jatropha curcas l.: a potential bioenergy crop - on field research in belize

Università degli Studi di Padova

Facoltà di Agraria

Dipartimento di Biotecnologie Agrarie

Laurea Magistrale in Scienze e Tecnologie Agrarie

Jatropha curcas L., a potential bioenergy crop.

On field research in Belize.

Relatore:

Prof. Mario Malagoli, Università degli Studi di Padova

Correlatore:

Dr. ir. Raymond Jongschaap, Wageningen University and Research centre,

Plant Research International

Laureando:

Berardo da Schio

Matricola n° 588712

Anno Accademico 2009/2010

If you use information from this M.Sc. dissertation document, please citeand refer to:

da Schio, B., 2010. Jatropha curcas L., a potential bioenergy crop. On fieldresearch in Belize. M.Sc. dissertation. Padua University, Italy and Wageningen University and Research centre, Plant ResearchInternational, the Netherlands.

“Sub umbra floreo”.

National motto of Belize.

Table of Contents

List of Abbreviations.........................................................................................................7

Abstract............................................................................................................................11

1.Introduction..................................................................................................................13

1.1 Energy crisis and global climate...........................................................................13

1.2 Jatropha curcas L., a potential bioenergy crop....................................................18

1.2.1 Knowledge gaps in Jatropha curcas L. research..........................................28

1.2.2 Selection of knowledge gaps and justification..............................................31

1.3 Aim and objectives of the thesis...........................................................................33

2.Materials and Methods.................................................................................................35

2.1 Research at PRI Wageningen, the Netherlands.....................................................35

2.2 On field research in Belize, Central America.......................................................36

2.2.1 Climate data..................................................................................................39

2.2.2 Maya Ranch trial...........................................................................................40

2.2.3 Warrie Head trial...........................................................................................44

2.2.4 Central Farm trial..........................................................................................45

2.3 Statistical analysis.................................................................................................49

3.Results and discussions................................................................................................51

3.1 Important drivers for Jatropha curcas L. growth and development and how are

these for Belize...........................................................................................................51

3.1.1 Radiation and light interception....................................................................51

3.1.2 Temperature...................................................................................................52

3.1.3 Water.............................................................................................................53

3.1.4 Vapour pressure and wind speed...................................................................53

3.2 Response of genetically different accessions to available resources in Belize.....55

3.2.1 Seed dimension and weight...........................................................................55

3.2.2 Seed germination rate....................................................................................58

3.2.3 Biomass development at nursery stage: LA, fresh weight, taproot length....60

Table of Contents

3.3 Resources use efficiency and optimization for jatropha crop conditions in Belize..

.....................................................................................................................................63

3.3.1 Plant density..................................................................................................63

3.3.2 Plant spacing.................................................................................................64

3.3.3 Crop management.........................................................................................71

3.4 Discussions...........................................................................................................80

4.Conclusions..................................................................................................................85

5.Acknowledgements......................................................................................................89

Annex 1. Growth parameters and sustainability indicators tables...................................91

Annex 2. Experimental designs.......................................................................................99

References.....................................................................................................................107

6

List of AbbreviationsAET............... Actual Evapo-Transpiration

aft. ….............after (in Annex 1)

agr. …............ agricultural (in Annex 1)

BNMS............Belize National Meteorological Service

BT.................. Bullet Tree

CBD...............Convention on Biological Diversity

CDM..............Clean Development Mechanism

CF.................. Central Farm

COCyTECH.. Consejo de Ciencia y Tecnología

comm. …....... communication

DM................ Dry matter

DMA............. Dry matter assignment

EEP................ Energy and Environment Partnership

EM.................Effective Micro-organisms

ERA-ARD..... Agricultural Research for Development; Dimension of the European Research Area

EU..................European Union

FACT............. Fuel on Agricultural Common Technology

FAO............... Food and Agriculture Organization of the United Nations

GHG.............. Greenhouse gases

GUARD.........Galen University – Applied Research and Development for SustainabilityInstitute

HI...................Harvest index

IEA................ International Energy Agency

IPCC.............. International Panel on Climate Change

JC...................Jatropha curcas L. (in Annex 1)

LA..................Leaf Area

LAI................ Leaf Area Index

LCA............... Life Cycle Analysis

MR.................Maya Ranch

NBS............... Nucleotide Binding Site

NGO.............. Non Governmental Organization

List of Abbreviations

OAS...............Organization of the American States

OM.................Organic Matter

PET................ Potential Evapo-Transpiration

pm..................parameter (in Annex 1)

PRI.................Plant Research International

PS...................Production system (in Annex 1)

T,M,B.............Top, Middle, Bottom branches (in Annex 1)

TSDF..............Tropical Studies and Development Foundation

UB................. University of Belize

UNEP.............United Nations Environment Programme

UNDP.............United Nations Development Programme

UNFCCC.......United Nations Framework Convention on Climate Change

USD...............United States Dollar

WH................ Warrie Head

WUR..............Wageningen University and Research centre

8

Ai miei genitori,

e ai miei nonni.

Abstract

Potentials of bioenergy crop Jatropha curcas L. are investigated through field trials in

Cayo District, Belize, Central America. Crop growth and development are monitored in

two jatropha plantations of one and six years, respectively in Warrie Head and Maya

Ranch. A third plantation is set up in Central Farm, in the framework of the '1st

Coordinated Call for a Transnational Research Activity under the ERA-ARD Net:

Bioenergy – an opportunity or threat for the rural poor', in the project 'Bioenergy in

Africa and Central America – Opportunities and Risks of Jatropha and Related Crops'.

Biomass development is assessed through measurements of dry fruit yield, LAI

development, length of effective branch, seed dimensions and weight, fruit to seed ratio

and seed to kernel ratio and seed germination test in relation to different crop variables,

according to the different trials: management, such as pruning and cropping system

(monoculture, intercropping and living fence), genotype, plant spacing and plant

density. Outputs on biomass development are linked with weather variables data, kindly

provided by the National Meteorological and Hydrological service of Belize.

Results indicate that Jatropha curcas L. has promising potentials to play a decisive role

in bioenergy scenario in Belize and the Region, for the favourable pedoclimatic

situation and the availability of genetic resources.

Key words: Jatropha curcas L. – Biofuels – LAI development – Belize – Tropical

agriculture.

RiassuntoIl potenziale della coltura energetica Jatropha curcas L. viene investigato in prove di

campo nel Distretto di Cayo, Belize, America Centrale. La crescita e lo sviluppo della

coltura vengono monitorati in due piantagioni di uno e sei anni, rispettivamente a

Warrie Head e a Maya Ranch. Una terza piantagione viene messa a dimora a Central

Farm, nel contesto della '1st Coordinated Call for a Transnational Research Activity

under the ERA-ARD Net: Bioenergy – an opportunity or threat for the rural poor', nel

progetto 'Bioenergy in Africa and Central America – Opportunities and Risks of

Abstract

Jatropha and Related Crops'.

Lo sviluppo della biomassa è stimato attraverso misurazioni di: produzione di frutta,

sviluppo del LAI, lunghezza effettiva dei rami, dimensioni e peso dei semi, rapporto in

peso di frutto e seme, prove di germinazione, in relazione a variabili differenti, secondo

le diverse prove: gestione colturale, come potatura e sistema colturale (monocoltura,

consociazione e recinto verde) genotipo, spaziatura e densità. Lo sviluppo della

biomassa viene confrontato in relazione ai dati sulle variabili climatiche, gentilmente

messi a disposizione del servizio Meteorologico ed Idrologico Nazionale del Belize.

I risultati indicano che Jatropha curcas L. mostra promettenti potenziali nello scenario

bioenergetico del Belize e della Regione, in ragione della situazione pedoclimatica

favorevole e della disponibilità di risorse genetiche.

Parole chiave: Jatropha curcas L. – Biocombustibili – indice di area fogliare LAI –

Belize – Agricoltura tropicale.

12

1. Introduction

Energy availability and energy use are issues of global concern and have been under

research worldwide for a long time. Attention is mostly given to reduce energy

consumption and to detect new and renewable energy resources, in order to cope with

the world energy crisis. Two main processes are responsible for this situation: first, the

increasing population and development rates are rapidly multiplying the global energy

demand in many countries; secondly, the great share that traditional fossil fuels occupy

on the global energy consumption can hardly be sustained. In fact, the ongoing fossil

fuels depletion has reached a stage where the current reserves seem not enough for

future needs. Furthermore the role of fossil fuels on climate change and global warming

can no longer be neglected (IPCC, 2007).

1.1 Energy crisis and global climate

High fossil fuel prices, the risks of fossil fuel dependence and the increasing greenhouse

gas (GHG) emissions derived from this kind of fuels are the main reasons to find new

and renewable energy sources for the coming years (FAO, 2008). In fact the current

energy crisis is mainly due to the high dependence on fossil fuels. It is now evident that

oil consumption is drastically increasing, while the reserves are rapidly diminishing

(Dowlatabadi, 2006), so it would be more relevant to talk about oil crisis than energy

crisis. Current global trends in energy supply and consumption are patently

unsustainable: environmentally, economically and socially. That indicates a global need

to secure the supply of reliable and affordable energy and to effect a rapid

transformation to a low-carbon efficient and environmentally benign system of energy

supply. It is also clear that current energy fossil fuel consumption trend will have severe

consequences on natural ecosystems and social communities. Switching to renewable

energy will therefore reduce global warming and curb actual trends (IEA, 2006). These

are the reasons why a search for alternatives to fossil fuels, such as renewable energy

from solar, wind, water, biomass and nuclear, has been provoked.

All renewable energy options have pros and cons and a global analysis should be

undertaken for each one of them. Various aspects of renewable energies will be

1.Introduction

discussed, but nuclear energy will not be taken into consideration.

The matter of renewable energy involves different forms and sources of energy.

According to the Unified Bio-Energy Terminology definition (FAO, 2004), renewable

energy consists of energy produced and/or derived from sources infinitely renovated

(hydro, solar, wind) or generated by renewable combustibles (sustainably produced

biomass). Renewable energy offers an interesting option to reduce fossil fuels

dependence and to reach climate change mitigation and if well consciously and

sustainably managed, it may help to preserve biodiversity, water and soil reserves, as

well as human livelihoods.

Due to its importance, international actors have expressed themselves on the subject.

The United Nations Framework Convention on Climate Change (UNFCCC, 1992)

supports bioenergy as one of the “precautionary measures to anticipate, prevent or

minimize the causes of climate change”. The 1997 Kyoto Protocol to the UNFCCC

recognizes the importance of renewable energy as a contributor to mitigating climate

change, with a view to assisting developing countries in achieving sustainable

development and enabling industrialized countries to comply with their quantitative

emission targets thanks to the Clean Development Mechanism. The Convention on

Biological Diversity (UNEP, 1992) is relevant to sustainable bioenergy development as

it commits parties to biodiversity conservation, the sustainable use of its components

and the fair and equitable sharing of benefits arising from the use of genetic resources.

Many different solutions to face worldwide changes on climate and on energy demand

are available. Alternatives to fossil fuels seem in fact numerous. The appropriate

solution to alleviate fossil fuel crisis and related climatic problems may vary according

to the local situation and taking into account social, economic and environmental

spheres. An interesting option that should be seriously taken into account in relation to

the local factors is represented by biofuels produced directly or indirectly from biomass.

They have been subject of many claims and researches during the past decades, and

they are now classified by the FAO as “First-generation” and “Second-generation”

biofuels. First generation biofuels are the ones mainly derived from food-crops,

14

1.Introduction

including sugar- and starch-based bioethanol and oilseed based biodiesel; while Second

generation biofuels are the ones derived from non-food crop agricultural and forestry

products, making use of the lignin, cellulose and hemicellulose components of plants

(FAO, 2008). Both first and second generation biofuels present good opportunities but

also have negative sides. In fact, on the one hand they are a remarkable option to

combat climate change and to reduce fossil fuel dependency, while on the other hand

they can directly or indirectly affect food security and do not play a relevant role in

GHG emissions mitigation. It is important to bear in mind that biofuels often compete

for land, water and nutrient resources and they can provoke an increase of food price.

However, in an optimized setting, (local) energy supply may contribute to productivity

increase and to the prosperity of livelihoods. A way to check the effectiveness of climate

change mitigation through biofuel production and use should be found, which means

identifying tools that allow comparing energy and GHG emission balances (inputs and

outputs) and indicating if a better action is effectively accomplished. Ultimately, the

impact of biofuels on livelihood should not be disregarded.

To date, energy and GHG emission balances are of high concern as researches on this

issue provoke great discussions. To loose this worry, life cycle assessments (LCA) are

used as tools that take into account different parameters and variables to define the best

improvement on an environmental scale: impacts are evaluated after different decisions

and management actions over the whole life cycle of a specific product. Indeed, the

benefits coming from renewable energies' strategy and management implementation are

linked to many variables, as the good opportunity of favourably impacting the

environment and the farmers' livelihoods. With regard to all these concerns, a further

broad question is attracting people’s attention and animating the worldwide debate on

energy: the struggle between local and global energy. In fact, energy consumption is an

issue present everywhere the humanity stands, and people are arguing on who is the

actor, on how and why the energy (or oil) production and distribution are controlled.

Globally, there is an increasing energy demand and a global concern on occurring

climate change, as well as a worldwide spread awareness of the necessity of finding

15

1.Introduction

alternatives. With regard to that, an emergent question is showing up: what consequence

would bring the development of a global energy based community and what if it is local

energy based. According to the previous discussion, it is important to remember that

global energy production can involve high energy losses due to the transportation itself

and risks of energy market monopoly or oligopoly. Local energy options seem to be

socially sustainable and economically viable, if proper infrastructures and services are

provided. Local energy development starts at a local scale, identifying the potential

alternatives to put into effect: in this regard, biofuels from agricultural crops often

represent a valuable opportunity. In relation to the local environmental and social

situations and to the pedoclimatic characteristics, many could be the suitable crops:

sugar crops (sugar cane, sugar beet, sweet sorghum), starchy crops (maize, wheat,

barley, rye, potatoes, cassava) and cellulosic material (switchgrass, Mischantus, willow,

poplar, crop stover) for the production of ethanol; oil crops (rapeseed, oil palm,

soybean, sunflower, peanut, Jatropha) for the production of biodiesel; biomass coming

from different crops but also from agro-industrial by-products and municipal wastes for

the production of biogas (FAO, 2008).

However, despite some possible negative impacts, many are the potential benefits of

bioenergy development. Indeed, it is clear the strong call for implementation strategies

that will act on the development of this sector. Often, well balanced policies and

accurate actions can strongly operate to maximize positive effects and reduce the

negative ones. As positive effects there are: diversification of agricultural output,

stimulation of rural development and contribution to poverty reduction, increase in food

prices and higher income for farmers, development of infrastructure and employment in

rural areas, lower greenhouse gas emissions, increased investment in land rehabilitation,

new revenues generated from the use of wood and agricultural residues, and from

carbon credits, reduction in energy dependence and diversification of domestic energy

supply, especially in rural areas, access to affordable and clean energy for small and

medium-sized rural enterprises. On the other hand, potential negative effects are

addressed to as reduced local food availability if energy crop plantations replace

16

1.Introduction

subsistence farmland and increased food prices for consumers. Demand for land for

energy crops may increase deforestation, reduce biodiversity and increase GHG

emissions. Increased number of pollutants, modification to requirements for vehicles

and fuel infrastructure, higher fuel production costs, increased wood removals leading

to degradation of forest ecosystems, displacement of small farmers and concentration of

land tenure and incomes, reduced soil quality and fertility from intensive cultivation of

bioenergy crops, distortion of subsidies on other sectors and creation of inequities

across countries represent some other alarming impacts (FAO, 2008).

A strong focus on this issue is necessary and more importance should be given to the

problems of biofuels’ production, by looking at them from an agricultural point of view.

To what concerns the fuels coming from food crops, the main problems seem to be the

competition for their destination as human food or animal feedstock and from the

competition for agricultural land resources, water, energy and nutrients. The fear

coming from the cultivation of food crops for energy production is also due to the

mismanagement of these crops. In fact, while climate change mitigation can be partly

achieved (if it is truly proved for some produce, for others should be cautiously

explored), mismanagement can lead to a loss of biodiversity, especially in the case of

repeated monoculture over the years, and in a reduced efficiency of water and soil

resources that are of vital importance. That is especially the case at the moment in non-

industrialized countries, where the demand for large area to place bioenergy plantations

is increasing (Wood, 2005; von Braun and Meinzen-Dick, 2009; Daey Ouwens et al.,

2007). The other option, represented by the use of “second-generation” biofuels, seems

to be of difficult and slow spreading in most countries at the present day, due to the lack

in technology knowledge and resources for processing the lignin component that is still

under development (FAO, 2008). What should not be forgotten is that second generation

biofuels might not affect the availability of food but they do compete for land, water,

nutrients and energy.

Thence, biofuels represent a valuable solution to mitigate global warming and to reduce

oil dependence. Nevertheless, significant objections are still heard against their use, as

17

1.Introduction

their consequences on communities could be positive as well as negative. Major

concerns lie in the selection of the fuel crop and its management in the cultivation and

processing steps: solutions may vary according to the regional context. Moreover, the

use of some fuel crops is controversial, as they have been proven to be not enough

efficient or useful. For some others, more research is required and their use as an energy

feedstock will heavily depend on how this research is carried out and how the results are

presented. Among these last mentioned, a relatively new energy crop is Jatropha curcas

L. (Figures 1.1 and 1.2).

1.2 Jatropha curcas L., a potential bioenergy crop

Jatropha curcas L. is a deciduous monoecious perennial shrub or small tree belonging

to the botanical family of Euphorbiaceae, to the tribe Jatropheae of the subfamily

Crotonoideae. Common name varies according to the region: in English it is called

'physic nut', while in Italian it is known as 'ricino d'inferno'. J. curcas probably

originated in southern Mexico or neighbouring parts of Central America, which are the

only areas where it has often been collected from undisturbed vegetations. It was then

distributed all over the world by Portuguese seafarers in the XVII century and is now

18

Figure 1.1. Jatropha curcas L. plantation atfruiting stage, in Maya Ranch, Belize, July22nd, 2009.

Figure 1.2. Jatropha curcas L. fruits, in MayaRanch, Belize, July 22nd, 2009.

1.Introduction

naturalized throughout the tropics and subtropics (Figure 1.3). Different parts of J.

curcas are used for a range of medicinal purposes; moreover it is a source of oil used for

soap production and as a source of energy, as mentioned before; it is also an important

hedge plant (Baldrati, 1950; Henning, 2007). Hereunder, a review of jatropha plants,

fruits, seeds and leaves (Figures 1.4, 1.5, 1.6 and 1.7).

19

Figure 1.4. Row of six years old Jatrophacurcas L. plants pruned at four years, inMaya Ranch, Belize, July 22nd, 2009.

Figure 1.5. Jatropha curcas L. dry fruit coatsand seeds. In the background, Arachispintoii growing as intercrop with jatropha, inMaya Ranch, Belize, July 22nd, 2009.

Figure 1.3. 'Global indication of the most suitable climate conditions for the growth ofJatropha (J. curcas L.) (30°N, 35°S) and Oil palm (Elaeis guineensis Jacq.) (4°N, 8°S)'.Source: Claims and Facts on Jatropha curcas L., Jongschaap et al., 2007.

1.Introduction

The plant ecophysiology and the botanical features have been investigated. The plant

develops a deep taproot and initially four shallow lateral roots (Figure 1.8). The stem,

arising from a thick, perennial rootstock, with watery to whitish latex, has a bark

smooth, grey or reddish, shiny, peeling off in papery scales. Leaves are alternate,

simple, petioled and glabrous, with a blade broadly ovate in outline, usually shallowly

5-lobed and margins usually entire. Terminal inflorescences contain unisexual flowers.

The fruit is a broadly ellipsoid capsule, smooth-skinned containing three ellipsoid seeds,

1-2 cm long, mottled black and coarsely pitted. Growth in J. curcas is intermittent and

sympodial, dormancy is induced by fluctuations in rainfall, temperature and light but

not all plants respond simultaneously. Pollination seems to be carried out by honeybees

and beetles (Bhattacharaya et al., 2005) and moths (Henning, 2007). In flowering, the

female flowers open one or two days before the males one; male flowers last only one

day. Seed never sets in indoor cultivation unless the flowers are pollinated by hand. J.

curcas occurs in semi-arid tropical and warm subtropical climates with mean

pedoclimatic surviving requirements as the followings: daily temperatures of 20-30°C,

annual rainfall of 300-600mm (but resistant to periods of drought of up to seven

months), absence of frost (Figure 1.9).

20

Figure 1.7. Six years old fruiting Jatrophacurcas L. plants, in Maya Ranch, Belize, July22nd, 2009.

Figure 1.6. One year old Jatropha curcas L.plant, in Warrie Head, Belize, July 22nd,2009.

1.Introduction

The main inputs for the production of oil-bearing fruits of J. curcas are land area

including the prevalent site characteristics, plantation establishment practices and

plantation management practices. The outputs are the seeds and other biomass elements

(Achten et al., 2008). J. curcas can grow in a wide range of soils: on degraded, sandy or

gravelly and even saline soil with low nutrient content. Nevertheless, clay soils are

unsuitable for the plant if water logging or saturation occurs due to the climatic

conditions. It is clear that J. curcas responds highly when growing on well aerated soils.

Sandy to loamy soils seem to be a best fit. Optimal pH reaction is considered between 6

and 8.5. The plant is well adapted to marginal soils with low nutrient content but in

order to support a high biomass production the crop shows a high demand for nitrogen

and phosphorus fertilization (Henning, 2007; Daey Ouwens et al., 2007). Among soil

proprieties, pH, EC, CaCO3, organic C and clay significantly affect the availability of

nutrients, thus soil conditions reflect the effect of jatropha cultivation practices on a

degraded soil. From the perspective of both soil structure and carbon and nitrogen

sequestration, jatropha cultivation under minimal soil disturbance can serve

‘environmental functions’. In fact, jatropha cultivation improves soil resistance to wind

erosion and enhanced macro-aggregate stability to water erosion. Under jatropha,

increased potential carbon sequestration rates are possible as stable micro-aggregates

21

Figure 1.9. Six years old Jatropha curcas L.plantation after an extraordinary dry month,in Maya Ranch, October 28th, 2009.

Figure 1.8. Particular of Jatropha curcas L.root system. Central taproot and four lateralroots are evident, in Belmopan, Belize,November 27th, 2009.

1.Introduction

can offer protection to organic carbon. Therefore jatropha cultivation programmes will

not only serve as a source of income-generation to resource-poor farmers but will also

improve the quality of their soils in the long run (Ogunwole et al., 2008).

Propagation is done by seeds or cuttings. Plants raised from seed are more resistant to

drought than those raised from cuttings, because of the taproot they develop. The

development of root system is then different, according to the originating part of the

plant (Achten et al., 2007). The taproot enables a straighter and deeper root system

growth so to extract moisture from deeper layers of the soil. This root structure is also

preferable in intercropping systems to minimize the competition for water and nutrients

between the different crops. Thereafter, nursery-grown seedlings have a higher survival

rate than direct-seeded ones and produce seeds earlier (Figure 1.10). Seeds in nursery or

direct seeding with seed treatment is recommended (Daey Ouwens et al., 2007). Seed

soaking in cold water for 24 hours is suggested for better and quick germination

(Kaushik et al., 2007), although it might influence more the germination celerity than its

rate (Sengfelder, personal comm.). At the onset of the rains the seedlings can be planted

in the field (Heller, 1996). It was noted that spacing of plants is a trade off between

biomass and fruit production. Thus, optimum spacing is differently achieved depending

on weather situation, site characteristic and intended objective (Achten et al., 2008).

Irrigation will depend on the climatic conditions of the location. Although J. curcas

can survive precipitation as low as 300mm by shedding its leaves, it does not produce

well under such conditions. Minimum and optimal rainfalls to produce fruits are

assessed on values of 600mm ha-1 y-1 and 1000-1500mm ha-1 y-1. Water and rains after

periods of drought will induce blossoming. Hence, too much rain and humidity will

provoke fungus, thus high rainfall might require other spacing (Daey Ouwens et al.,

2007). Indeed, an economic sustainable oil production is achieved with higher minimum

requirements of water of at least 750 mm annual rainfall or supplementary irrigation

(Henning, 2007). Plantations aiming at oil production might also need artificial or

organic fertilization. Fertilizers at least compensate the nutrient removal due to harvest

or management practice (e.g. pruning). Simultaneous reclamation of barren lands and

22

1.Introduction

biodiesel production will inevitably imply use of fertilizer and irrigation (Achten et al.,

2008).

Pruning is a very important issue as it determines to a large extent, although not

completely, seed yield in each site and it can facilitate manual and mechanical

harvesting of fruits (Figure 1.11). Canopy size determines the maximum number of

flowering branches. Large trees on a low planting density or smaller plants on high

densities can apparently both result in sufficient flowering branches (Daey Ouwens,

2007). The pruning should be done when the tree sheds leaves and enters a period of

dormancy (Kaushik et al., 2007), that is usually coinciding with the dry season. Cultural

practices in new plantations, thence, include regular weeding, pruning and fertilization.

Standard management count on a plant density field design of 1350-2500 plants ha-1

(Henning, 2007).

Diseases and pests attacks should not be underestimated. Opinions on this issue are

contrasting. In fact, Henning (2007) says that intervention against pests and diseases

occurs rarely and just in the case of powdery mildew (Uncinula necator), Alternaria

spp., and caterpillars of Spodoptera litura and several species of phytophagous beetles,

and particular attention must be put on intercrops grown together with J. curcas, as it

23

Figure 1.11. Six years old Jatropha curcas L.plant pruned two years before, in MayaRanch, Belize, July 22nd, 2009.

Figure 1.10. Jatropha curcas L. seedlings aweek after sowing, in Bullet Tree, Belize,September 30th, 2009.

1.Introduction

can be an alternative host (e.g. Cassava mosaic virus). While Daey Ouwens et al. (2007)

say that the plant is vulnerable to most common pests and diseases found in food crops,

adding that most of these pests and diseases can be treated fairly easily and, if required,

biologically.

Basic agricultural operations are done manually, and so harvesting and separation of

seeds from fruits. Handling after harvesting foresees a careful exsiccation in the shade

until 6-9% moisture content. Subsequently the extraction of the oil can be done

following different techniques (Henning, 2007). The reported yields range from

extremely low to high; Jongschaap et al. (2007) conclude to a potential yield range of

1.5-7.8 dry seed ha-1 y-1. As mentioned above, yield depends on site characteristics

(temperature, radiation, rainfall, soil type and soil fertility), genetics (a strict selection of

seeds or cuttings leads to more uniformity in offspring and higher yields per plant),

plant age and management (propagation method, spacing, pruning, fertilizing, irrigation,

etc.) (Daey Ouwens et al., 2007; Achten et al., 2008).

The oil contained in the seeds, around 35% by weight (Baldrati, 1950; Kandpal and

Madan, 1995; Ginwal et al., 2004; Jongschaap et al., 2007), has to be expelled or

extracted. For extraction of the jatropha oil two main methods have been identified:

mechanical extraction (with manual ram press or engine driven screw press) and

chemical extraction (aqueous enzymatic or solvent oil extraction). Finally the oil may

be refined in a continuous transesterification reactor to produce biofuel or diesel oil and

glycerol as a valuable by-product. The oil quality is dependent on the interaction of

environment and genetics (Jongschaap and van Loo, 2009; Achten et al., 2008). Thus,

the cake attributes change in relation to the oil characteristics and the oil extraction

method used. Anyway, the cake contains high-quality proteins and various toxins. The

presence of biodegradable toxins makes the fertilizing cake simultaneously serving as

biopesticide/insecticide and molluscicide. Anyway, it is advisable to check the absence

of phorbol esters in the crops grown on jatropha cake fertilized land, certainly in crops

for human consumption. Digesting the cake and bringing the effluent back to the field is

thought to be the best practice at present from an environmental point of view. Due to

24

1.Introduction

the toxicity of the seeds and oils, some attention should be paid to the human health and

work environment impact categories (Achten et al., 2008).

Available genetic resources show several types of J. curcas. Low-toxic type from

Mexico, type with larger leaves and larger but fewer fruits and seeds from Nicaragua,

male sterile type which produce more fruits than normal types, just to quote some

examples. A study on 200 J. curcas accessions from different regions around the world

highlighted, among other characteristics, the differences in oil composition that could be

regionally identified (Jongschaap and van Loo, 2009). In order to start breeding the

genetic variation needs to be assessed. Most plant material used so far is derived from

simple selection within semi-wild populations or landraces. Between-plant variation of

vigour and seed yield are tremendous and great genetic improvement in seed yields and

other important characteristics may, therefore, be expected from systematic breeding

(Figure 1.12). Obviously, oil yield per hectare will dominate breeding objectives for J.

curcas cultivars for biofuel production. Cultivars with compact growth would facilitate

harvesting (Henning, 2007). Literature reports lack of genetic variation. To date, it is

assessed a high phenotypic variation (e.g. plant architecture) in material from Latin

America (Figure 1.13). Genetic variability was found low in African and Indian J.

curcas accessions but high in Guatemalan and other Latin American ones. Diversity in

J. curcas should be found in wild species, in their centre of origin in Mexico, Central

and South America (Jongschaap and van Loo, 2009; Montes et al., 2008). Plant

breeding programmes should be carried out after a more through analysis of the existing

genetic resources and variability, that would allow getting the characteristics that would

be required. Among the most important and urgent features to be investigated, there are:

toxicity of seeds, oil-seed and seedcake (source of protein that could be suitable for

animal feedstock); drought resistance and water requirements under different

pedoclimatic situations; plant susceptibility to pests and diseases.

25

1.Introduction

Concerning environmental impacts of J. curcas production system, the main issues are

the energy balance, impact on global warming potential and land use impact. Energy

balance of J. curcas biodiesel is reported to be positive and the total energy inputs into

the crop to the energy output ratio is estimated at 1:4-5 (Henning, 2007). The available

information shows that energy balance improvement options lay in the cultivation,

where irrigation and fertilization are the most energy intensive practices, and

transesterification steps. How positive the balance is in reality, will mainly depend on

how efficiently the by-products of the system are used. Impact on global warming

potential showed a reduction of GHG emissions for the production of biodiesel from J.

curcas in comparison to fossil fuels. However, the removal of (semi-) natural forest for

the introduction of J. curcas is expected to have a significant negative effect on the

GHG balance of the whole life cycle. Ultimately, it is expected that land occupation

impact of J. curcas on the soil will be positive, as the plant is observed to improve soil

structure, is strongly believed to control and prevent soil erosion and sequestrates

carbon. Nonetheless, being an exotic species in most actual growing areas, the impact of

land use change towards J. curcas on biodiversity is expected to be negative, although

this will largely depend on the mix of land use which is replaced by J. curcas and on

how the plant is cultivated (Achten et al., 2008).

J. curcas’ considerable potential as an oil crop for biofuel purposes at relatively low

26

Figure 1.13. Particular of stem and lateralbranches of a year old Jatropha curcas L.plant, in Warrie Head, July 22nd, 2009.

Figure 1.12. Seed coats and kernels of threeaccessions of Jatropha curcas L., inBelmopan, Belize, November 2nd, 2009.

1.Introduction

costs and modest demands on the local agro-ecosystem has received much attention in

recent years. It is foreseen that within the next decade or so, J. curcas will become a

major source of renewable energy in the drier rural areas of (sub) tropical Asia, Africa

and America (Henning, 2007). The promise of J. curcas as a species to produce high

quantity and quality feedstock for bioenergy is considerable. First, yields are expected

to increase over the years as seed improvement takes effect; they are expected to reach 6

to 7 ton dry seeds ha-1 y-1 within few years, but only under optimal climate conditions,

using high yielding strains, and optimal soil fertility conditions. Looking at such

promise, it is concluded that jatropha might be an alternative for other oil producing

plants such as oil palm, especially for less humid areas (Daey Ouwens, 2007).

The role of J. curcas in bioenergy generation looks like to be of great interest; in fact,

biodiesel production from jatropha seeds give an optimistic impression of the capability

to combine the low-technology inputs required for oil production with other agricultural

interesting claims on the plant. In fact, many are the claims regarding J. curcas, and its

development as an agricultural crop appears to have many positive effects. The present-

day hype for this plant comes from the theoretical combination of all the good features

that characterize J. curcas cultivation, however they are not always scientifically proven

and barely come out altogether simultaneously in the same site. In fact, many good

characteristics of this plant appear to exist because of its rusticity and an intensive

exploitation it is not like to be supported by scientifically sound agronomic data. Indeed,

often good resistance characteristics are not linked with high productivity values

(Jongschaap et al., 2007). To understand better the limits and the potentials that J.

curcas crop growth may result from a more intensive and focused farming, the main

agronomic characteristics, the physiological behaviours, the reactions to different sites

and the relevance of genotype or environmental influences should be known, and if not,

they should be meticulously detected and, afterwards, explained to farmers. Keeping

this assessment in mind and looking at an objective of J. curcas cultivation techniques

improvement, knowledge gaps on botanical features, potential utilizations, claims and

facts regarding J. curcas and its production system will be hereunder briefly described

27

1.Introduction

and explained. In any case, a clear statement can be extrapolated: the plant cannot

perform all its functions together at the best level.

1.2.1 Knowledge gaps in Jatropha curcas L. research

Despite the huge interest that J. curcas production system has attracted by now, a lack

of knowledge and available data is evident. The main gaps concern some basic

agronomic characteristics, the application of the good agricultural practices, the

development of a complete J. curcas production system (including oil yield

characteristics and oil processing) and the input/output balances at all these stages.

Moreover, information is still required to assess the nutrient requirements and the dry

matter assignment in different agricultural settings and pedoclimatic conditions. There is

lack of data also in reported genetic variability that would allow beginning plant

breeding programmes. Further research towards the discovery of the potential of

utilization of other J. curcas products and by-products would be very welcome.

Accurate data on yield and on its characteristics are missing. In order to respond to the

J. curcas oil production want of a list of countries, in which incredible large areas, that

are drastically increasing, are planned to be grown with this plant, reliable information

on crop requirements and climate/soil characteristics are still very much required (Daey

Ouwens et al., 2007). Much agronomic and breeding work needs still to be done to

maximize oil production potential per ha and thus improve the economic sustainability

of jatropha oil production. To this, rapid multiplication techniques and facilities have to

be developed to make improved planting material available in adequate amounts. This is

especially urgent as planting of unimproved material not only leads to low returns on

investments but may also lead to a loss of interest in this crop (Henning, 2007).

Concerning the plant cultivation, substantial efforts should be made to streamline

observations in current jatropha planting sites, to implement specific experiments for

unravelling the impact of different production factors on crop performance and to

exchange knowledge and information, in order to prevent unjustified investments. It is

recognized that the main knowledge gaps are situated in the cultivation step, where a

28

1.Introduction

description of the best practice and the potential environmental risks or benefits are

needed. In fact, basic agronomic proprieties are not exhaustively understood and the

environmental effects have not been investigated yet (Achten et al., 2008). Correct

spacing should be identified depending on different intended objectives and much has

still to be learned from plant manipulation, from more or less intensive pruning or

curving of branches, at different moments. As a new technology, the micropropagation

is being developed by Manurung (Daey Ouwens et al., 2007; Achten et al., 2008).

Taproot potential has not been investigated scientifically. The susceptibility of J. curcas

to pests and diseases is a source of discussion and is believed to depend on the

management intensity. More experiments are needed where the growth effect on

different kinds of crops are monitored in intercropping systems. Impacts on soil

structure, water-holding capacity, soil decomposition, organic matter content and soil

biological activity should be brought under detailed investigation as well. Dominant

role of environment over genetics in seed size, seed weight and oil content (Achten et

al., 2008) should be more deeply investigated. Much research is still necessary to

improve yield, to exactly understand the energy efficiency of the plant under different

conditions, to allow use of bioproducts such as oil cake as animal fodder (Daey Ouwens

et al., 2007).

Nutrient requirements for maximum oil production are not well-defined for J. curcas

(Henning, 2007). No information is available on nutrient cycles and the impact on soil

biological life (Achten et al., 2008). The relation between plant nutrients, organic matter

content of the soil and micronutrients and yields is not fully understood (Daey Ouwens

et al., 2007). Jatropha has not been domesticated yet and basic knowledge of its soil-

plant relations is required for the development of appropriate agricultural techniques.

Very little is known about foliar nutrient content of jatropha and soil-plant relationship,

which is essential to domesticate the plant and establish the nutrients requirements

(Chaudhary et al., 2008).

The input levels to optimize the harvest index (HI) in given conditions are yet to be

quantified. Very limited information is available regarding acidification, eutrophication,

29

1.Introduction

and other LCA impact categories of the J. curcas production cycle. Increased

investigation of the cultivation step in the production of jatropha biodiesel will enable

researchers to assess the specific contribution of the plant in these impact categories as

well. As the reduction of global warming potential is one of the main aims of the J.

curcas biodiesel system, this confirms the research need on input-responsiveness of the

J. curcas cultivation step.

Good documented yield data are still scarce. Seed yield and biomass production in

different environmental and abiotic settings, varying provenances or accessions and

applying different levels of different inputs should be monitored in order to discover the

input-responsiveness of the plant in different settings as well as the interactions between

the different inputs and the interaction between the environmental and genetic set-ups

and the inputs. Notwithstanding, there is still insufficient information to account the

nutrient and water needs for specific environmental and genetic set-ups. The actual

potential of J. curcas cultivation should be explored, as it is not clear if the plant is able

to produce ecologically and socio-economically viable amounts of energy in barren

situation (Achten et al., 2008). From selection of basic plant material up to yield, there

are many options, with a lot of variation in available data and not enough information

for optimization. More research should also be initiated on medicinal proprieties of

different parts of the plant, e.g. wound healing, antimalarial and anti-HIV effects, and

investigation of the agronomic and medicinal potential of other Jatropha species would

be valuable as well (Henning, 2007).

J. curcas is still a wild plant with a wide variation in growth, production and quality

characteristics. In order to start breeding towards high yielding biodiesel plantations, the

best suitable germplasm has to be identified for different cultivation situations

(Henning, 2007; Daey Ouwens et al., 2007; Achten et al., 2008). For this reason,

research makes progresses thank to new patent free molecular marker technology :

conserved sequence based on NBS-gene family. A starting point in this sense could

reasonably be intercrossing ‘elite’ J. curcas accessions (e.g. ‘Cabo verde’) with low

toxic and toxic accessions as starting point for breeding, now that genetic analysis of

30

1.Introduction

segregating population is possible (Montes et al., 2008). More research is necessary on

oil content, oil quality/acidic composition and the influence of environment and genetics

on it. Vegetable oil can be used as base for liquid engine fuel in various ways; choice of

extraction method is clearly dependent on the intended scale of activity; crucial research

and development options lay in the maximization of the transesterification efficiency at

minimal cost. About this, an important issue is the improvement in the catalytic process,

certainly the recovery and the reuse of the catalyst. As part of the option of

decentralized processing units, low-cost, robust and versatile small-scale oil

transesterification designs should be developed (Achten et al., 2008).

1.2.2 Selection of knowledge gaps and justificationThe above mentioned statements and knowledge gaps lead the interest and the

requirement of further research that is now the case. A broad investigation appears to be

necessarily addressed to all the mentioned topics; however the evident risk of being

imprecise would necessary bring to a selection. As, to date, some major knowledge gaps

of the whole J. curcas production system are in the cultivation step, a deep analysis into

that will put in evidence the need of looking for growth variables in monoculture,

intercropping and hedges, as well as looking for sustainability indicators, also in these

three production systems.

Growth Parameters are of major concern to understand net primary production of the

plant, its potential and actual energy and water use efficiencies, its nutrient

requirements. In general, growth parameters are needed to better understand the

ecophysiology of the plant so to allow a full implementation of its potentials, adding the

required inputs. Concerning J. curcas growth parameters, a general overview will be

given. Firstly, a description is presented of growth parameters by plant parts: seed, root,

stem/wood, leaf, flower, fruit and whole plant (Annex 1a). In this section some of the

reported data are followed by annotations that would explain whether there were

exceptional conditions when the data were recorded. That is the case of seed

germination, oil quality, apical dominance and fitness. In fact, seed germination varies

31

1.Introduction

apparently depending on different pre-treatments; oil quality, that is its physical-

chemical proprieties and its constituent composition, varies under environmental

conditions and genotype (Jongschaap and van Loo, 2009; Achten et al., 2008). To what

concern apical dominance and plant fitness, it must be said that plant breeding is still in

its infancy. Variability in plant architecture between different accessions is reported

(Montes, 2008). Then, growth parameters are intended under different farming

condition. Three cropping systems are taken into account: monoculture, intercropping

and living fence. Same growth parameters in the three cases are reported and differences

between values will highlight differences between farming systems (Annex 1b).

The potential of jatropha oil production at a small scale and its implementation as a tool

for rural development lead to a necessary investigation of sustainability indicators. A

sustainability indicator is a parameter that allows understanding the impact of an action

at different levels, mainly environmental, economic and social. This indicator should be

clear enough to describe accurately the input/output ratio of each step of an entire

process and tell whether it is more or less sustainable. In the case of the J. curcas

production system, sustainability indicators will be identified and, firstly, divided into

agronomic, environmental, economic and social spheres (Annex 1c). These categories

were chosen to better explain the interactions between J. curcas production system

internal and external factors and actors. Then, an overview of sustainability indicators

will be given for different cropping systems: monoculture, intercropping and living

fence (Annex 1d), as above considered. A deeper investigation in this sense will allow

to define which one of the production systems is expected to be more sustainable. Here

a right and proper specification: often the results depend on local or regional variables

that are unable to be chosen or modified.

A relief of basic parameters coming out from the analysis of growth variables and

sustainability indicators and an attempt to link them together should eventually give a

general idea of growing patterns and impacts of the different J. curcas production

systems.

32

1.Introduction

1.3 Aim and objectives of the thesis

J. curcas production system is attracting worldwide Institutions, Companies and

Organizations attention, both for its oil yield suitable for biodiesel uses and for its

capability to sustainably interact with rural tropical and sub-tropical world. A lot of

projects are now taking place in Countries all over the world to assess the feasibility of

the set-up of J. curcas production systems and their implementation at different scales

and in relation with different realities and conditions.

The present work is a part of a wider research promoted by the 1st Coordinated Call for

a Transnational Research Activity under the ERA ARD net (the Agricultural Research

for Development; Dimension of the European Research Area): “Bioenergy – an

opportunity or threat to the rural poor”. Specifically, a joint consortium of academic,

governmental and private institutions has proposed the interdisciplinary research and

capacity development project “Bioenergy in Africa and Central America – Opportunities

and Threats of Jatropha and Related Crops”, thus selecting two main foci: a crop, the

Jatropha curcas L., and the regions, Central America and East Africa. The objective of

ERA-ARD is to follow the growth and development of Jatropha curcas by monitoring

important dynamic crop variables in different production systems and densities, and

relate them to the environmental circumstances. The opportunity that I have to join this

ERA ARD proposal has included a research on crop growth and processing at Tropical

Studies and Development Foundation, in Belmopan, Belize, under the scientific

guidance of Plant Research International, Wageningen, the Netherlands.

The main research activity was held in Belize and consisted on gathering crop growth

and development data from existing plantations (LAI, yield) and to set up a field trial, in

view of establishing the growth and development of Jatropha curcas L., and searching

the links between these data to the environmental variables. The aim to share knowledge

and to set up discussions on biofuels at national and regional levels is also pursued. In

Belize, the goodness of jatropha as an oil feedstock and as a tool for rural development

at small and medium farm size will be evidenced by further research, looking at the

results in the coming years.

33

2. Materials and Methods

The work was structured and developed in two periods. The first period, from 14th April

to 14th May 2009, was spent at Plant Research International (PRI) of the Wageningen

University and Research centre, the Netherlands, and was directed to the bibliographic

research and study of the state of the art on the jatropha plant and the whole jatropha

system, with a focus on the cultivation. Research activities have also been undertaken in

the greenhouse, such as for leaf area index (LAI) and light interception measurements,

and in the laboratory, such as for oil extraction. The second period, from 15th July to 15th

December, was dedicated to the field research in Belmopan, Belize, at the NGO

Tropical Studies and Development Foundation (TSDF), with the collaboration of Galen

University – Applied Research and Development for Sustainability Institute (GUARD)

and the University of Belize (UB).

2.1 Research at PRI Wageningen, the Netherlands

During the research period in Wageningen twenty-six jatropha plants from four different

accessions from Central America coded as 160 (7 plants), 176 (9 plants), 177 (7 plants)

and 184 (4 plants) were grown in a greenhouse experiment for leaf area (LA)

measurements and for assessing the interception capacity of photosynthetically active

radiation (PAR). The plants were five months old, they were daily watered in the

morning and evening and exposed to 12 hours of light, from 7.00 to 19.00 hours. For

each plant, cotyledons and leaves were counted, and length (L) and width (W) of each

leaf was measured; then leaf area was calculated according to the following formula:

A=0.84∗L∗W 0.99

(Liv Soares et al., 2007). Jatropha light interception was also measured through a beam

('SunScan Canopy Analysis System, type p.SS1'), which could measure the fraction of

photosynthetically active radiation (PAR) intercepted by the plants at different levels in

the canopy (top, middle and bottom) and in fifteen different plant densities (Table 2.1).

This research phase allowed testing a methodology for LA estimation on field and light

interception calculations that were later used for the research activities in Belize.

Part of the research activity was carried out in the chemical laboratory, where oil was

2.Materials and Methods

extracted from jatropha seeds and weighed. Kernels were separated from shells,

smashed and mixed with the solvent: 7.5ml of hexane per round of extraction (3 times)

with about 0.4g to 1.0g of kernel (van Loo, 2009, personal comm.).

2.2 On field research in Belize, Central America

Belize, Central America, has a total land area of 22.966 km2. The Country is located at

17°15' N, 88°45' W, with climate characterized by a dry and a rainy (June to November)

season and mean annual rainfall from 1524mm in the north to 4064mm in the south

(Figures 2.1 and 2.2) (CIA World Fact Book, 2009; Belize National Meteorological

Service, 2009). Central Region, where the trials of the present research are located,

shows a primary and secondary rainfall maxima occurring in June and September; in

this region, main soil type is cambisol (FAO et al., 2009). In the Country, jatropha is

known as physic nut and used for curative purposes; just recently it received more

attention by the Ministry of Agriculture and some private investors, although policies on

bioenergy and market for jatropha products are lacking.

36

Table 2.1. Fifteen J. curcas plant set-ups for LAIand light interception measurements(Jongschaap et al., unpublished data)

Treatment Length Width Area(m) (m) (m) (m) (m2)

1 1,00 0,90 3,00 4,50 13,502 1,00 0,60 3,00 3,00 9,003 1,00 0,45 3,00 2,25 6,754 1,00 0,30 3,00 1,50 4,505 0,90 0,90 2,70 4,50 12,156 0,90 0,60 2,70 3,00 8,107 0,90 0,45 2,70 2,25 6,088 0,90 0,30 2,70 1,50 4,05

9a 0,60 0,90 1,80 4,50 8,109b 0,60 0,60 1,80 3,00 5,4010 0,60 0,45 1,80 2,25 4,0511 0,60 0,30 1,80 1,50 2,7012 0,45 0,45 1,35 2,25 3,0413 0,45 0,30 1,35 1,50 2,0314 0,30 0,30 0,90 1,50 1,35

Row Distance

Plant Distance


Field trials were performed in three areas in Belize: at Maya Ranch, a six year old

jatropha plantation; at Warrie Head, a one year old jatropha plantation; at Central Farm,

a new plantation of jatropha, whose design was set up at Wageningen. These three trials

were treated and monitored trough the study of different variables: crop growth and

development was monitored through the Leaf Area Index (LAI) measurement (a non-

destructive method useful in yearly biomass production assessment) in all the three

trials, while yield was measured only at Maya Ranch. Measurements on seed dimension

and a germination test, other biomass production and crop development indicators, were

performed at Bullet tree, the nursery for the jatropha seedlings destined to Central Farm

trial. Environmental variables taken into consideration were: climatic data (the same for

the three trials) and soil samples (at Central Farm trial, only). Locations of

meteorological stations and experimental sites are shown in figure 2.3.

37

Figure 2.2. Map of Belize andits Districts (source:http://www.watersidebelize.com/images/belize_map.jpg).


38

Figure 2.3. Map of Belize and location of meteorological stations (PhilipGoldson International Airport and Central Farm) and experimental sites(Maya Ranch, Warrie Head, Bullet Tree and Central Farm).(Source: http://www.hydromet.gov.bz/AgroClimat_Stations.htm).


2.2.1 Climate data

Climate data collection was a kind concession from the Belize National Meteorological

service (www.hydromet.gov.bz). Weather variables were recorded on a daily basis

(Table 2.2), through two climate stations: one station was settled at Philip Goldson

International Airport (17°32' N, 88°18' W) and recorded radiation (kJ m-2 d-1), vapour

pressure (kPa) and wind speed (m s-1); the second one, in Central Farm (17°11' N,

89°00' W), recorded Min and Max temperatures (°C) and precipitation (mm d-1). Both

stations were selected as the closest available to trials and able to record the required

data on a daily basis. However, actual weather variables in the experimental sites might

slightly differ. In fact, trials occurred in different locations at around 100km to 140km

from Philip Goldson International Airport and 1km to 25km apart from Central Farm

weather stations (Figure 2.3).

Table 2.2. Weather variables required on a daily basis.

Abbreviation Weather variable Unit

Rad Radiation (kJ m-2 d-1)Tmax Maximum temperature (°C)Tmin Minimum temperature (°C)VP Vapour pressure (kPa)WS Wind speed (m s-1)P Precipitation (mm)

39


2.2.2 Maya Ranch trial

Maya Ranch field trial, with an area of almost 0.5ha, is located at the 4th mile on the

Caracol Road, in Cayo District, at an altitude of 150 meters above the sea level (Figures

2.4 and 2.5), in a location out of the main routes. The area is surrounded by tropical

rainforest and was formerly used as pasture for sheep, then abandoned. In June 2003,

TSDF transplanted around five hundred jatropha seedlings, from seeds harvested from

wild spontaneous and backyard grown isolated trees. Jatropha was planted in the

context of an Organization of American States (OAS) funded agro-forestry project, that

involved the planting of a teak plot (Tectona grandis) that still exist beside the jatropha

field, and the sowing of Habanero peppers (Capsicum sp.) and Arachis pintoii as

suitable inter-crops for jatropha. To date, A. pintoii is still growing on the south-east side

of the jatropha plantation and is giving positive feedback since it is a leguminous able to

control weed and its cultivation does not require much labour. A. pintoii, known in

Belize as Pinto peanut (English) and Maní forrajero (Spanish), is a perennial herb that

develops a strong taproot and forms a dense mat of stolons and rhizomes up to 20 cm

deep; there are low and highland species (up to 1400m) that show high tolerance to

shade and drought. It has been used as a forage legume in intensively managed

grass/legume pastures and tree plantations, or as a ground cover in tree plantations

(Cook, 1992). Its key benefits are weed control, nitrogen fixation and ability to lower

surface temperature for better soil health and moisture.

The project was temporarily suspended, in 2006/2007, and the whole area was left

abandoned, until July 2009, when the jatropha field became a trial to the purpose of the

current research for which an inventory was done, on 22nd July. The inventory lead to

the following results: 458 plants were counted, organized in 8 rows. The distances are

4m between rows and 2m between the plants within the row (1250 plants ha-1). The field

is oriented on a south-north axis and a slight slope gradient is present in this direction,

from the south side where the upper part is, to the north, at the bottom of the field

(lower part). In the field, three sets of jatropha plants were recognized: i) the plants of

the two west side rows and the last six or seven plants of each row at the bottom of the

40


field appeared smaller and less vigorous than the others, and they were barely bearing

fruits, as a result probably of less deep soils on this side and water logging at the bottom

of the field; ii) about one third of the plants towards the northern part had been pruned

in 2006/2007, they presented long and straight upward branches and already some

fruits; iii) the remaining two thirds consisted on the largest trees, with many branches

that closed completely the rows and were bearing a lot of fruits in groups of three to

eight racemes, A. pintoii was found growing below these plants. Two-meter high wild

herbaceous vegetation was growing along the field and in the surroundings, which have

been cut by machete twice during the growing season, in July and October 2009.

Beginning a research activity on a field at that stage required some quick decisions,

therefore two trials were initiated: they have been developed in separate times during

the growing season but both of them have been set up in the same field and considered

the same jatropha plantation. The first trial A (27th July – 10th August) focused on the

harvest, while the second trial B (1st September – 1st December) on LAI measurements,

as described below.

For the first trial A, 'pruning' and 'intercropping' were identified as already existing

treatments, and two plots were selected within the field: one with pruned plants growing

in monoculture (named 'pruned'), and, the other one with not-pruned plants under which

A. pintoii was vigorously growing (named 'not pruned')(see annex 2, table a). Fruits

41

Figure 2.5. Jatropha curcas L. plantation, inMaya Ranch, Belize, August 11th, 2009.

Figure 2.4. Jatropha curcas L. row inintercropping with Arachis pintoii, in MayaRanch, Belize, August 11th, 2009.


were harvested and dried separately by plot. The harvest was done on 7th July and 10th

August, 2009, and fruits were left drying under a roof during four to six weeks. After

this period, the fruits have been weighed on a 100g precise scale separately as follows:

7th July-pruned, 7th July-not pruned, 10th August-pruned and 10th August-not pruned.

From each of the four groups, a 2% fruit sample (between 140g and 740g) was picked

and coats and seeds were separated and weighed on a 1g precise scale. From each of the

four groups, a 100g seed sample was chosen and shells and kernels separated and

weighed on a 1g precise scale. Moreover, one thousands of randomly selected fruits

were opened: the number of seeds per fruit was counted and the average coat to seed

weight ratio was measured on a 1g precise scale. A 100 seed sample was crushed and

shell to kernel ratio was measured on a 1g precise scale.

For the second trial B, two already existing treatments were identified: pruning and

intercropping, and three plots were selected according to their cultural management, as

follows: 'intercrop/not pruned', 'monoculture/pruned' and 'monoculture/not pruned' (see

annex 2, table b). 'Pruning' referred to those plants that had been pruned two years

before at an height of 60cm, and, as intercrop, A. pintoii was maintained because its

easy-to-cultivate characteristics and its reciprocal benefits with J. curcas had been

noted. To record jatropha growth and development, 90 monitoring plants were selected

for LAI measurements: 36 plants from the 'intercrop/not pruned' plot, 18 from the

'monoculture/pruned' plot, 36 from the 'monoculture/not pruned' plot. LAI

measurements and estimation have been performed on 1st September, 1st November, 1st

December, according to the methodology described in table 2.3. The choice of different

amount of monitoring plants in the plots was necessarily taken as a trade off between

the existing situation and the new research objectives. Furthermore, on the 1st November

and the 1st December, the length and the effective length of representative branches of

the monitoring plants were measured to report the leaf production and fall off trends.

Effective branch is expressed as the segment of the branch in which green leaves are

still growing. This methodology allowed to monitor two aspects of plant growth and

development: first, to record the branch part actually involved in solar radiation

42


interception and to monitor how its length changes during the season; secondly, to

observe the plant dry matter production potential and its nutrients cycle, for what

concern leaf production and decay, from the soil deeper layers to the leaves back to the

soil, on the superficial layers.

Further calculations were made to find out intercepted solar radiation by the leaves of

the monitoring plants, applying the following formula:

1−e−k∗LAI

from Beer's Law formula for light interception, first described for plants by Monsi and

Saeki (1953), where k=0.68, in the case of J. curcas L. (Jongschaap, unpublished data).

Table 2.3. Estimation method of the Leaf area per tree. 1Estimation method per leaf presented at

Expert seminar on J. curcas L. (March 2007) (Jongschaap et al., 2007).

(example

data)

unit

Measure the length of a representative branch a 0.75 (m)

Count the number of leaves on this branch b 17 (#)

From the mid-section of the representative branch, select

a representative leaf. Measure the length from the point

where the leaf sheath is attached to the petiole to the

opposite point of the leaf

c 21.5 (cm)

Measure the maximum width of the leaf, perpendicular

on axis of the previous measurement

d 18.5 (cm)

Estimate how often this representative branch ‘fits’ in

the monitoring tree (e.g.5.5 similar branches)

e 5.5 (#)

Leaf Area1 = 0.0001 m2 cm-2 * b * 0.84 * (c * d)0.99 * e 3.50 (m2 tree-1)

43


2.2.3 Warrie Head trial

Warrie Head field trial, about 0.8ha large, is located just off the 9th mile of the Western

Highway, from Belmopan to San Antonio, in Cayo District, at an altitude of 45 meters

above the sea level (Figures 2.6 and 2.7). The area is a private property, surrounded by

forest, and at the border of the Belize River. In 2008 the land was cleared from the

prevalent graminaceae wild vegetation and ploughed. In July of the same year, in the

framework of an OAS-EEP research project, TSDF planted around five thousands

jatropha seedlings of two accessions (from Guatemala and Cuba, the Cuban being called

'Cabo Verde'), at two different spacings (3*1.7m alternated with 1.7*1.7m and 4*1m)

but resulting in the same plant density of 2500 plants ha-1. Water soluble polyacrylamide

(ultra-fine water-soluble polymer/acrylamide providing benefits as soil conditioning

agents) in one half and effective micro-organisms (a biological product that contains a

mixture of beneficial organisms, such as lactic acid bacteria, yeast, and phototrophic

bacteria) on the other half of the field were sprayed (Baumgart and Sengfelder, personal

comm.). On the short sides of the trial, additional jatropha seedlings were transplanted

and not sprayed with micro-organisms. An irrigation system was installed. In October

2008, almost two thirds of the jatropha plants were uprooted and died, as a consequence

of an extraordinary flood from the Belize River. The field was left abandoned until its

rehabilitation as a trial for the current research, in July 2009.

44

Figure 2.6. Jatropha curcas L. plantation andparticular of irrigation system (not in use), inWarrie Head, Belize, August 11th, 2009.

Figure 2.7. Jatropha curcas L. plantation(distance 1.7m between the two centralrows), in Warrie Head, Belize, August 11th,2009.


For this trial, the preparatory inventory lead to the following results and assumptions:

1476 plants were counted, the majority of them being the additional plants in the sides

of the EEP-OAS trial; these plants survived the flood because they were growing in a

slight hilly area; the treatments still existing after the flood were genotype and plant

spacing; at this point on time the micro-organisms previously sprayed are most likely

lost and not able to interfere in the plantation; concerning the plant size, a great

phenotype variability was evident (individual height from 0.3m to 3m), but plant

architecture appeared quite similar and suggested a strong competition for light with

wild herbaceous vegetation; apparently, soil is deep. During the trial, the field was

cleared by machete and bush-hogger twice, in July and in October 2009. As shown in

annex 2, table c, the field is organized in four groups, divided by genotype and plant

spacing in: Guatemala-(3*1.7)*1.7m2 (328 plants), Cuba-(3*1.7)*1.7m2 (370 plants),

Cuba-4*1m2 (387 plants) and Guatemala- 4*1m2 (391 plants), where (3*1.7)*1.7m2

spacing consists in the 'double row' and 4*1m2 is 'single row'. Both spatial design result

in 2500 plants ha-1. The research activity, then, started from this situation and focused on

LAI measurements. Each group was divided in three sub-plots and six monitoring plants

have been chosen from each sub-plots. In total, the same 72 plants (18 per group) were

selected for LAI measurements four times in the growing season on 2nd September, 2nd

October, 2nd November and 2nd December. The methodologies used for LAI

measurements and estimation and for effective branch length measurements are similar

to the ones applied for Maya Ranch trial, as well as the formula used to calculate

intercepted solar radiation.

2.2.4 Central Farm trial

The trial in Central Farm was established in the framework of the project 'ERA-ARD

Biofuels in Africa and Central America 2009-2013'. The preparatory work consisted on

the experimental design finalization and on the seed retrieval. The on field activities

have been carried out in two places: the sowing was done in a nursery at Bullet tree and,

two months after, the seedlings were transplanted on field at Central Farm.

45


The nursery was set up at Bullet tree, three miles off the west end of the Western

Highway, in Cayo District, at an altitude of 80 meters above the sea level (Figures 2.8

and 2.9). At the nursery stage data on seed dimension were taken, a germination test, LA

measurements and destructive biomass assessment were performed, from the seed to the

two month old seedlings. The nursery was located in a vegetable organic farm, and teak

seedlings were present, too. Once a week all the plants, including the jatropha, were

sprayed with a micro-organisms mixture that granted the sanity of the seedlings during

this raising period. For the purpose of the ERA-ARD project, three seed accessions have

been used: the Belize local one, collected in Maya Ranch, the Guatemalan G17

provided by the company 'Biocombustibles de Guatemala' and a low-toxic Mexican

provided by the 'Universidad Autónoma Chapingo'. The average 100-seed weight was

established weighing 937 Mexican seeds, 822 Guatemalan and 1000 Belizean on a 1g

precise scale. The length and the width of hundred seeds per accessions were measured,

and the length to width ratio was calculated. Hundred seeds per accession were crushed,

and shell and kernel were weighed separately. After these measurements, on the 23rd

September, 1144 seeds per accessions were sown in black cylindrical perforated plastic

bags, 20cm high and 10cm in diameter, filled with local soil and rice husks (Figure 2.8);

they were watered twice daily and sprayed with an EM mixture once a week. More

Belizean seeds were sown: 288 on the same day and 1088 on the 9th October, in the

context of the EEP project. Surveys at the nursery were done on the 30th September, 2nd

and 7th October, and on the 21st October for the last sown seeds: germinated seeds and

standing plants were counted. At the nursery stage, ten plants per accessions were

randomly selected and LA measurements were performed one month after the

germination (3rd November), and at the moment of transplanting (26th November,), using

the same methodology explained for Maya Ranch trial. On the 26th November, the same

ten plants per accessions were uprooted and dried under a roof for two weeks: on the

11th December dicotyledons, leaves, petioles, stems and roots were counted and weighed

on a 1g precise scale. All stems and some leaves of Guatemalan (11 leaves) and

Belizean (1 leaf) accessions were still green and fresh. Tap root lengths were measured.

46


On the 26th November, 1494 jatropha plants were transplanted on a 0.6ha field at UB

Campus, according to the design in annex 2, tables d and e. Additionally, 504 plants

were transplanted on the north side of the experimental plot (264 plants, 0.15ha) and on

the south (240 plants, 0.14ha) (see annex 2, table f). The field selected is located on the

top of a hilly area at Central Farm, in Cayo District, at an altitude of 60 meters above

the sea level (Figure 2.10). The field is east to west oriented and has a pig house on the

east side, a vegetable garden and the additional jatropha on the south, orange trees on

the west and the natural forest on the north, beyond the additional jatropha strip. There

is a slight slope gradient going downwards from south to north. Formerly, there was an

orange plantation, then, nearly half of the field was covered by meadow and half

cultivated with corn (on the east side). The field has been bush-hogged, cleared and

plough prior the transplanting. The transplanting followed the trial set up: a randomized

blocks design with three factors and three repetitions (see annex 2, table d). The factors

were three genotypes: Mexican, Guatemalan and Belizean; three agricultural production

systems: monoculture, intercropping with A. pintoii and living fence; two plant densities

of about 1250 and 2500 plants ha-1, organized in spacing of 3.7*2.2m2 and 3.7*1.1m2 in

the plot (monoculture and intercropping) and 0.25m and 0.5m in the living fence. There

were twelve treatments per block, repeated in three blocks, resulting in a total of 36 sub-

plots in the field. Moreover, six treatments repeated four times for a total of 24 segments

47

Figure 2.9. Jatropha curcas L. nursery, inBullet tree, November 2nd, 2009.

Figure 2.8. Sowing Jatropha curcas L.seeds, in Bullet Tree, Belize, September23rd, 2009.


in the living fence. In each of the thirty-six block, six monitoring plants (which had at

least 1 border row in the sub-plot) were selected and LAI measurement was performed,

on the 2nd December, using the same methodology explained for Maya Ranch trial

(Figure 2.11). For the statistical analysis, although, the design was reinterpreted, as, at

the time of the first LAI measurement, intercropping was not available and genotype

and plant density were the only factors. The trial was treated as a complete randomized

block design for the analysis of the variance, though not two repetitions per three blocks

have been considered but totally six repetitions for each treatment.

On the 10th December, after the transplanting of jatropha but before A. pintoii was in the

ground, representative soil samples were taken from each of the three blocks at 0-20cm,

20-50cm and 50-100cm depths. For the size of the experiment, six random pits per

block were prepared and samples from the three depths extracted with an auger. In total,

nine soil samples were collected for different soil characteristics (Table 2.4).

48

Figure 2.11. LAI measurements of Jatrophacurcas L. with technicians from the Ministryof Agriculture and the University of Belize,an example of knowledge sharing andinstitutional strengthening, in Central Farm,Belize, December 2nd, 2009.

Figure 2.10. Transplanted Jatropha curcasL. seedlings at 60 days, in Central Farm,Belize, November 26th, 2009.


Table 2.4. Soil variables required for 1st soil characterization.

Abbreviation Soil variable Unit

Sand% Sand (%)Silt% Silt (%)Clay% Clay (%)BD Bulk density (g cm-3)OM% Organic Matter content (%)C% Carbon content (%)Norg% Organic Nitrogen content (%)N Mineral nitrogen (ppm)P Available Phosphorous (ppm)K Potassium (ppm)

2.3 Statistical analysis

The collected data were analysed and organized in factorial spreadsheets, using

OpenOffice.org Calc. Average, standard deviation and standard error of the treatments

of each trial were calculated. Thereafter, descriptive methods have been used for climate

data, fruit yield at Maya Ranch, jatropha seed dimensions and germination rate in Bullet

Tree; while, on data collected at Maya Ranch (LAI and effective branch length), at

Warrie Head (LAI and effective branch length) and at Central Farm (LAI) the software

Anova97 ver. 3.12 (Onofri, 1997) was used to perform the analysis of the variance. In

each trial, monitoring plants were grouped and averaged by treatment and block (or

repetition), and the average of these groups were compared, to the purpose of the

ANOVA. To differentiate the means, the Duncan test with P=0.01 was applied in all the

cases, except where otherwise specified.

49

3. Results and discussions

Outcomes of the preparatory research in Wageningen and of the on field research in

Belize, for the period July – December 2009, are presented in this chapter.

3.1 Important drivers for Jatropha curcas L. growth and

development and how are these for Belize

Weather variables, soil composition and nutrients availability are main drivers that

contribute to characterize the pedoclimatic condition of an agro-ecological zone and

directly influence crop growth and development. In the current research it was possible

to gather climate data, provided by the Belize National and Meteorological Service. To

this purpose, the closest available climate stations were used: in Central Farm (1km to

25km apart from the experimental sites), to record temperature (Min and Max) and

precipitation, and at Philip Goldson International Airport (100km to 140km apart from

the experimental sites), to record radiation, vapour pressure and wind speed. With

regard to this, it should be reminded that this situation may have influenced some

findings of this research: in fact, it is possible that radiation, vapour pressure and wind

speed values recorded in a station by the coast of the Caribbean sea and close to a large

urban area (Belize City, 70000 inhabitants) may differ from actual values occurred more

than 100km in the inland in less populated areas. Hereunder, climatic situation in Belize

for the year 2009 is summarized on a daily basis.

3.1.1 Radiation and light interception

Over the whole year 2009, radiation showed the highest mean value in May, where it

reached more than 18kJ m-2 d-1; since then, mean monthly values were constantly and

gradually declining to 12kJ m-2 d-1 recorded in December (Figure 3.1).

To analyse resource use efficiency, solar radiation interception was measured. Light

interception formula for jatropha has been calculated in a trial at PRI Wageningen,

where measurements and calculations on jatropha at different plant densities indicate

that value of coefficient 'k' is 0.68. However, it changes according to different LAI: in

fact, for LAI>7, k=0.55 and for LAI<1-1.5, k=0.75 (Jongschaap, unpublished data).

3.Results and discussions

3.1.2 Temperature

Mean monthly temperatures have been recorded to be between 15 and 35°C, with

average Maximum temperature around 31°C and minimum around 21°C. Both Max and

Min temperature values were above the mean from April to October (Figure 3.2).

52

Figure 3.1. Mean monthly values of radiation recorded at Philip Goldson International Airportmeteorological station, in Belize, 2009. Source: Belize National Meteorological Service,personal communication.

J F M A M J J A S O N D

0

5

10

15

20

Weather variables, Belize, 2009Mean monthly values - Philip Goldson International Airport station

Radiation [kJ m -2 d-1]

Figure 3.2. Mean monthly values of minima (Temp. Min.) and maxima (Temp. Max.)temperatures recorded at Central farm meteorological station, in Belize, 2009. Source: BelizeNational Meteorological Service, personal comm.


0

5

10

15

20

25

30

35

40

Weather variables, Belize, 2009Mean monthly values - Central Farm station

Temp. Max. [°C]

Temp. Min. [°C]


3.1.3 Water

A total yearly precipitation of 1476mm was recorded in Central Farm, where the driest

period occurred from February to May, with about only one sixth of the yearly

precipitation (245.1mm); while the wettest months have been June, July, August and

November, totalling 792.2mm, equivalent to more than a half of total yearly

precipitation. Oddly, October was recorded to be exceptionally dry, being the driest

month with only 31.4mm of rainfall (Figure 3.3). Given this information, the beginning

of the growing season of jatropha could have been most likely established in June, when

important precipitations occurred on the 5th (72mm) and between 16th and 20th

(86.4mm).

3.1.4 Vapour pressure and wind speed

Vapour Pressure was at lowest levels of around 25kPa in the beginning of the year, then

increased from April, reaching maximum values between June and September when it

was recorded at around 32kPa; it finally came down to values close to 27-28kPa in the

last two months of the year (Figure 3.4).

53

Figure 3.3. Total monthly values of precipitation (Tot. Precip.), number of days of rain andmean monthly precipitation (Mean Precip.) recorded at Central Farm meteorological station, inBelize, 2009. Source: Belize National Meteorological Service, personal comm.


0

50

100

150

200

250

300

Rainfall distribution, Belize, 2009Total monthly values - Central Farm station

Tot. Precip. [mm]

Days of rain [#]

Mean Precip. [mm]


Wind speed mean values over the year were recorded to be around 3m s-1, with slightly

above-the-mean values from January to July and slightly below-the-mean in the rest of

the year (Figure 3.5).

54

Figure 3.4. Mean monthly values of vapour pressure (Vap.Press.) recorded at Philip GoldsonInternational Airport meteorological station, in Belize, 2009. Source: Belize NationalMeteorological Service, personal communication.


0

5

10

15

20

25

30

35


Vap.Press. [kPa]

Figure 3.5. Mean monthly values of wind speed recorded at Philip Goldson InternationalAirport meteorological station, in Belize, 2009. Source: Belize National Meteorological Service,personal communication.


0

1

2

3

4

5


Wind Speed [m s-1]


3.2 Response of genetically different accessions to available

resources in Belize

Different accessions have been used in the three trials: local Belizean, in Maya Ranch,

and Cuban and Guatemalan, in Warrie Head, where plants were already in the ground;

while in Central Farm, seeds from Mexico, Guatemala and Belize were analysed and

sown. In this section, firstly, seed morphological characteristics, and, secondly,

responses to agro-ecological condition in Belize are reported. Results achieved in

Central Farm trial are treated in the frame of work package 1 'Crop growth and

processing' of the ERA-ARD project 'Bioenergy in Africa and Central America –

Opportunities and Threats of Jatropha and Related Crops'. Results obtained refer to seed

dimension, germination, LA, fresh seedling weight and taproot length, during the

nursery stage in Bullet Tree, and to LAI measurements during transplanting in Central

Farm.

3.2.1 Seed dimension and weight

Measurements of length, width and hundred seed weight of J. curcas L. were

determined for three genotypes: a low-toxic Mexican, a Guatemalan (G17), and a local

Belizean accession. Guatemalan seeds were recorded among the largest for dimensions,

(Figures 3.6, 3.7 and 3.8) and weight (Figure 3.9). Guatemalan average seed length was

above 1.8cm and had 100-seed weight of 73g. Mexican and Belizean seeds had an

average length slightly under 1.8cm and a 100-seed weight, well below Guatemalan

values, at 58g for Mexican seeds and 55g for Belizean seeds (Figure 3.10).

55


56

Figure 3.6. Length of jatropha seeds as average of a hundred seed sample peraccession. Seed accessions are from Mexico (low-toxic), Guatemala (G17) andBelize (local). 2009.

1.35 1.45 1.55 1.65 1.75 1.85 1.95 2.05 2.15

0

10

20

30

40

50

Length of jatropha seeds of three accessions, Belize, 2009Bullet Tree, nursery

Mexico

Guatemala

Belize

Class central value [cm]

Fre

qu

ency

[# o

f se

eds

]

Figure 3.7. Width of jatropha seeds as average of a hundred seed sample peraccession. Seed accessions are from Mexico (low-toxic), Guatemala (G17) andBelize (local). 2009.

0.82 0.87 0.92 0.97 1.02 1.07 1.12 1.17 1.22

0

10

20

30

40

50

Width of jatropha seeds of three accessions, Belize, 2009Bullet Tree, nursery

Mexican

Guatemalan

Belizean

Class central value [cm]

Fre

qu

ency

[# o

f se

eds

]


57

Figure 3.8. Length to width ratio of jatropha seeds as average of a hundred seedsample per accession. Seed accessions are from Mexico (low-toxic), Guatemala(G17) and Belize (local). 2009.

1.46 1.54 1.62 1.7 1.78 1.86 1.94 2.02 2.1

0

10

20

30

40

50

Length:width ratio of jatropha seeds of three accessions,Belize, 2009 - Bullet Tree, nursery

Mexico

Guatemala

Belize

Class central value

Fre

qu

ency

[# o

f se

eds

]

Figure 3.9. Weight of 100 seeds of J. curcas L. of accessions from Mexico (low-toxic), Guatemala (G17) and Belize (local). 2009.

Mexico Guatemala Belize

0

10

20

30

40

50

60

70

80

Weight of 100 seeds of jatropha of three accessions, Belize, 2009Bullet Tree, nursery

Shell [g]

Kernel [g]

Accessions

We

ight

of 1

00 s

eed

s [g

]


3.2.2 Seed germination rate

After measuring the seed dimensions, 1144 seeds per accession were sown and

germination rate and standing plants were recorded three times. One week after sowing,

the majority of seeds already germinated, however differences among accessions were

noticed; more than 85% of Mexican and Guatemalan seeds germinated, while only 70%

of Belizean seeds germinated after one week. Two weeks after sowing, Mexican seeds

recorded the highest germination rate (96%), followed by Guatemalan (91%) and

Belizean (80%) seeds (Figure 3.11); after that moment, germination was not surveyed

any longer. Standing plants, that are upraised plants with open cotyledons, were counted

at the same time intervals and results were calculated as percentage over sown and

germinated seeds. Significantly different results were obtained for the three genotypes.

At the time of the first survey, less than 3% of jatropha plants from Mexican seeds were

standing, while Guatemalan and Belizean showed standing rates of 37% and 22% over

sown seeds (Figure 3.12) and 44% and 32% over germinated seeds (Figure 3.Error:

Reference source not found). However, two weeks after sowing, more than 99% of

58

Figure 3.10. Length, width, length to width ratio (L:W ratio) and weight of jatrophaseeds as average of a hundred seed sample per accession. Seed accessions arefrom Mexico (low-toxic), Guatemala (G17) and Belize (local). 2009.

Length [cm] Width [cm] L:W ratio Weight [g]

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Average dimensions of jatropha seed of three accessions,Bullet Tree, nursery

Mexico

Guatemala

Belize


plants from germinated seeds of all the accessions were standing (Figure 3.13).

59

Figure 3.11. Germination rate of J. curcas L. seeds of three accessions, on 1144seeds per accession monitored in intervals of 7, 9 and 14 days after sowing. Seedsfrom Mexico (low-toxic), Guatemala (G17) and Belize (local). 2009.

2009.09.23 2009.09.30 2009.10.02 2009.10.07

0

10

20

30

40

50

60

70

80

90

100

Germination rate [%] of 1144 jatropha seeds of three accessions,Belize, 2009 - Bullet Tree, nursery

Mexico

Guatemala

Belize

[%] o

f ge

rmin

ate

d s

eed

s

Figure 3.12. Standing plants as percentage of sown seeds of J. curcas L. of threeaccessions. 1144 seeds per accession monitored in intervals of 7, 9 and 14 daysafter sowing. Seeds from Mexico (low-toxic), Guatemala (G17) and Belize (local).2009.

2009.09.23 2009.09.30 2009.10.02 2009.10.07

0

10

20

30

40

50

60

70

80

90

100

Standing plants as [%] of sown jatropha seeds of three accessions,Belize, 2009 - Bullet Tree, nursery

Mexico

Guatemala

Belize

[%] o

f sta

ndi

ng

pla

nts


In general, Mexican low-toxic seeds showed a slower but more effective germination

characteristic, Guatemalan accession G17 were the quickest plants to stand with a

satisfying germination rate, while Belizean local seeds depicted the lowest, but

acceptable, germination rate and an average standing plant percentage compared to the

other accessions.

3.2.3 Biomass development at nursery stage: LA, fres h weight,

taproot length

During two months at the nursery stage, leaf area (LA) measurements on jatropha

seedlings of the three accessions were performed twice, one month after germination

and at the time of transplanting. The analysis of the variance revealed high significant

differences for the factor 'date' and the interaction 'genotype x date'. In fact, at the first

survey in the beginning of November, no significant differences were found among the

three genotypes. Instead, in the second survey, after a month, significant differences

were found between Mexican and Belizean genotypes, while LA of Guatemalan

60

Figure 3.13. Standing plants as percentage of germinated seeds of J. curcas L. ofthree accessions. 1144 seeds per accession monitored in intervals of 7, 9 and 14days after sowing. Seeds from Mexico (low-toxic), Guatemala (G17) and Belize(local). 2009.

2009.09.23 2009.09.30 2009.10.02 2009.10.07

0

10

20

30

40

50

60

70

80

90

100

Standing plants as [%] of germinated seeds of jatropha of threeaccessions, Belize, 2009 - Bullet Tree, nursery

Mexico

Guatemala

Belize

[%] o

f sta

ndi

ng

pla

nts


seedlings were not significantly different from the other two accessions. Considering the

effect of date separately per accessions, it was found that LA of Belizean seedlings did

not differ significantly between dates, while LA of both Mexican and Guatemalan

seedlings were greater and significantly different at the time of the second survey than

of the first (Figure 3.14).

Additional information about early biomass development of jatropha seedlings came out

from the measurements of taproot length and weight of ten individuals per accession at

the time of transplanting. Results on taproot length analysis indicated that there is a

significant difference, for P=0.05, between Guatemalan and Mexican accessions, while

Belizean accession did not significantly differ from the two other accessions (Figure

3.15). Fresh seedlings of Guatemalan origin seedlings produced more biomass than

others in the first two months of life (Figure 3.16), which can be related to the seed

dimensions, as an indication for the growth reserves available in the seeds. Belizean

accessions with more or less same seed weight but with lower kernel weight (Figure

3.9) grow slower than the other accessions, but invest relatively more dry matter in

61

Figure 3.14. Mean LA of ten jatropha seedlings of three accessions, from Mexico(low-toxic), Guatemala (G17) and Belize (local), measured about one and twomonths after germination. 2009. The same letters above the histograms indicatethat between the treatments significant differences were not found at the Duncantest, with P=0.01.

2009.11.03 2009.11.26

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

0.040

c

a

c

ab

bc bc

LA measurements on jatropha of three accessions, Belize, 2009Bullet Tree, nursery

Mexico

Guatemala

Belize

LA

[m2

*pla

nt-1

]


roots.

Jatropha seedlings dry weight could not be properly measured, since a stove was not

62

Figure 3.16. Fresh weight of ten jatropha seedlings of three accessions, from Mexico(low-toxic), Guatemala (G17) and Belize (local). 2009.

Fresh w eight [g]

0

5

10

15

20

25

Fresh weight of jatropha seedlings of three accessionsBelize, 2009 - Bullet Tree, nursery

Mexico

Guatemala

Belize

[g]

Figure 3.15. Taproot length of ten jatropha seedlings of three accessions, fromMexico (low-toxic), Guatemala (G17) and Belize (local). 2009. The same lettersabove the histograms indicate that between the treatments significant differenceswere not found at the Duncan test, with P=0.05.

Taproot [cm]

0

5

10

15

20

25

30

b

aab

Taproot length of jatropha seedlings of three accessionsBelize, 2009 - Bullet Tree, nursery

Mexico

Guatemala

Belize

[cm

]


available. As a result, two weeks after uprooting and air drying, the young plants' stems

were still green. However, some indicative data were acquired: in two weeks, uprooted

seedlings lost from one quarter to one third by weight; stems were still green and

accounted for the three quarters of the weight; the remaining weight (one quarter) was

divided over roots, petioles and leaves according to the ratio 4:1:4, approximately, for

all three accessions.

3.3 Resources use efficiency and optimization for jatropha

crop conditions in Belize

In the three trials, different agricultural features were considered (plant density in

Central Farm trial, plant spacing in Warrie Head trial and crop management in Maya

Ranch trial). LAI development and effective branch length were recorded in order to

measure part of the plant biomass development and to reveal differences between

different treatments, in view to eventually evaluate resources use efficiency and

optimization for the crop.

3.3.1 Plant density

One week after transplanting jatropha seedlings in Central Farm, LAI measurements

were performed, on December 2nd. Data showed the plant density as the factor that

influenced the LAI values in the different combinations (genotype x plant density). At

the same plant density, no significant differences were found between genotypes (Figure

3.17). Although not significantly different, LAI of Belizean plants were the lowest

among genotypes at high density (circa 2500 plants ha-1) and LAI of Guatemalan plants

were the highest among genotypes at low density (circa 1250 plants ha-1).

63


LAI measurements performed after transplanting in the fields of Central Farm resulted

in smaller values than the ones in the nursery in Bullet Tree, even if occurred one week

after. The reason might be searched in the loss of leaves by the plants during the

transportation from the nursery to the field ('transplanting shock').

3.3.2 Plant spacing

Results from Warrie Head trial deal with LAI and length of effective branch, measured

in four treatments, as a result of the combination of two genotypes (Guatemalan and

Cuban jatropha accession), and two plant spacing designs, single row (4*1m2) and

double (3*1.7)*1.7m2.

To compare the mean values of the four treatments, LAI values are first presented by

date and in a summary graph for all dates. On September 2nd, the only statistically

significant difference was found between the 'Guatemala-double row' plot and the

'Cuba-single row', with LAI values greater than 0.08 in the first one and below 0.06 in

the second. The other two plots, 'Cuba-double row' and 'Guatemala-single row', did not

show statistically significant differences with any of the treatments (Figure 3.18). At the

64

Figure 3.17. LAI measurements of J. curcas L. two month old seedlings of threeaccessions, from Mexico (low-toxic), Guatemala (G17) and Belize (local), at twoplant densities, Central Farm, Belize, 2009.

ca 1250 plants*ha-1 ca 2500 plants*ha-1

0.000

0.001

0.002

0.003

0.004

0.005

c

a

bc

a

c

ab

LAI measurements on jatropha of three accessions andtwo plant densities, Belize, 2009 - Central Farm trial

Mexico

Guatemala

Belize

Plant density

LA

I [m

2*m

-2]


time of the second survey, on October 2nd, no differences were noticed between the LAI

values for the four treatments (Figure 3.19). Later on in the season, statistically

significant differences were observed between LAI values in 'Cuba-double row'

treatment, with more than 0.06m2 of leaf per m2 of soil, and the two accessions in 'single

row', both of them having LAI between 0.03 and 0.04, but these were not significantly

different. LAI of jatropha in 'Guatemala-double row' plot was not significantly different

from the other three treatment (Figure 3.20). Again, towards the end of the growing

season, on December 2nd, no significantly differences were observed between the LAI of

jatropha growing under the four treatments, being at values around 0.025 (Figure 3.21).

65

Figure 3.18. LAI measurements on J. curcas L. on September, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.

Guatemala, (3*1.7)*1.7m2Cuba, (3*1.7)*1.7m2

Cuba, 4*1m2Guatemala, 4*1m2

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09 a

ab

b ab

LAI measurements on jatropha, Belize, 2009September 2nd - Warrie Head trial

Treatment (Genotype, Spacing)

LA

I [m

2*m

-2]


66

Figure 3.19. LAI measurements on J. curcas L. on October, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.



0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

aa

aa

LAI measurements on jatropha, Belize, 2009October 2nd - Warrie Head trial


LA

I [m

2*m

-2]

Figure 3.20. LAI measurements on J. curcas L. on November, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.



0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

ab

a

b b

LAI measurements on jatropha, Belize, 2009November 2nd - Warrie Head trial


LA

I [m

2*m

-2]


An overview of the LAI measurements resulting from monitoring of jatropha in the

Warrie Head plantation from September to December is hereunder provided. Spacing is

influencing LAI of jatropha in the first part of the monitoring period, while effects

caused by genotype are not statistically significant. This behaviour suggests a greater

biomass development capacity in plants in a double row than the ones, more closed, in

the single row, at the same plant density of 2500 trees ha-1. However, the jatropha plants

were relatively young (only fifteen months) and have never been pruned, and they did

not have many lateral branches. Factor 'date' showed its effects especially reducing

differences towards the end of the season. LAI values in 'Guatemala-double row' had a

more gradual reduction towards the end of the growing season than LAI in the other

three treatments. 'Cuba-double row' LAI showed an abrupt difference between

November and December, while LAI of jatropha in 'single row', between October and

December (Figure 3.22). The design of the Warrie Head experiments were blocked

perpendicular on the slope gradient; however, it might be that the location of the

'Guatemala-double row' treatment, closer to the margins of the forest and to the river,

could have attenuated the effects of the weather variables along the season, especially in

67

Figure 3.21. LAI measurements on J. curcas L. on December, 2nd, in Warrie Head,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.



0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

a a a a

LAI measurements on jatropha, Belize, 2009December 2nd - Warrie Head trial


LA

I [m

2*m

-2]


the drought of October. Moreover, the analysis of the variance highlighted differences

among the blocks, with the block in the middle having generally higher values than the

ones on the sides.

Additional information on jatropha growth potentials is obtained through the calculation

of intercepted radiation by the plants in the growing season. As they are mainly

depending on the LAI, values of intercepted radiation are following the same LAI trends

discussed above. Solar radiation was slightly decreasing from September to December,

however, due to limited interception capacity of the low LAI, plants were only able to

use a small amount of the available radiation (Figure 3.23; note the log scale). This

situation might suggest a potential improvement of solar radiation use by jatropha, in all

the situations. Basically, to improve radiation interception, LAI should be increased by

management actions that, on the one hand, induce more and larger branches and leaves

that stay green longer in the season, such as pruning (strongly recommended as the

plantation is still young), and, on the other hand, increase plant density and plant

capability to completely close the rows, such as spacing at transplanting and curbing

68


branches, thus to optimize the use of available space.

The 'effective branch' length measurements supported the results obtained for LAI,

although not completely, highlighting statistically significant differences between dates,

October 2nd and December 2nd (Figure 3.24) and blocks. No significant differences were

found between genotypes and spatial arrangement of the rows. The lengths of effective

branch in Warrie Head trial were similar to the ones in Maya Ranch, during the same

dates of survey, mainly around 10-12cm in November and 4-5cm in December.

However, in relative terms, length of effective branch was almost double in Maya

Ranch than in Warrie Head, being around 20% and 10% of the whole branch length in

the first site and around 10% and 5% in the second, in the dates considered (Figure

3.25).

69

Figure 3.23. Solar radiation, LAI of jatropha under different treatments (combinations of twogenotypes and two spacings: Guatemala-double row, Cuba-double row, Cuba-single row andGuatemala-single row) and intercepted radiation are represented from September to December,in Warrie Head, Belize, 2009.

S O N D S O N D S O N D S O N D

0.01

0.1

1

10

100

Solar radiation, jatropha LAI and intercepted radiation, Belize, 2009Warrie Head trial


LAI [m2 m-2]

Intercepted radiation [kJ m -2 d-1]

Treatment (from left to right: Guatemala- and Cuba-double row, Cuba- and Guatemala-single row )and date (September, October, November, December)


70

Figure 3.24. Length of the 'effective branch' (part of the branch with green leaveson), in J. curcas L., Warrie Head, Belize, for October 2nd, November 2nd andDecember 2nd, 2009. The same letters above the histograms indicate that betweenthe treatments significant differences were not found at the Duncan test, withP=0.01.



0

5

10

15

20 a

ab

aa

abc abcabc

abc

c c bcbc

Jatropha 'effective branch' length, Belize, 2009Time series - Warrie Head trial

2009.10.02

2009.11.02

2009.12.02


Effe

ctiv

e b

ran

ch [c

m]

Figure 3.25. Relative length of the 'effective branch' (part of the branch with greenleaves on) as percentage of the whole branch, in J. curcas L., Warrie Head, Belize,for October 2nd, November 2nd and December 2nd, 2009.



0

5

10

15

20

25

Jatropha 'effective branch' relative lenght, Belize, 2009Time series - Warrie Head trial

2009.10.02

2009.11.02

2009.12.02

Treatment (Genotype, Spacing)Effe

ctiv

e b

ran

ch a

s [%

] of t

ota

l bra

nch


3.3.3 Crop management

As in the case of Warrie Head trial, assessing jatropha biomass development was the

objective of the research in the Maya Ranch plantation, as well. Results from Maya

Ranch trial refer to yield, LAI and length of the effective branch.

Firstly, results from fruit and seed production are given. It must be underlined that yield

values are referred to as dry weight production. Separately, for the two plots considered

and for the two dates of harvesting, yield values are given under three forms: reported as

harvested per plot, as an average per plant and extrapolated to a unit surface basis (kg

ha-1). Data are indicating different production potentials in the plots considered (Table

3.1). Over the season, in the treatment 'Not pruned', where plants have never been

pruned and were growing in intercropping with A. pintoii, jatropha fruit production was

double than the one in the treatment 'Pruned', where, instead, jatropha plants were

growing in monoculture and have been pruned two years before (Figure 3.26).

Specifically, fruit production from 'Not pruned' treatment was almost triple at the

moment of the first harvest and one tenth higher at the second harvest. However, fruit

production trends revealed important differences between the time of the two harvests;

in fact, during the season, production from 'Not pruned' treatment decreased almost by a

half, while production from 'Pruned' plot increased by 70% (Figures 3.27 and3.28).

Cautiously, it has to be reminded here that production losses seemed to be significant: in

fact, by the time of the first harvest, fruits were already on the ground and have not been

collected; moreover, after the second and last harvest, fruits have been seen on the

plants and on the ground up till mid November, and some plants were still flowering in

October. These considerations suggest that potential production is bigger than measured,

although it is difficult to determine how bigger. An estimation of the production that

could not be harvested may be possible, considering the fruiting period (mid July to end

October), the harvested yield in the period from July 27th to August 10thand its trend for

the different treatments, the average dry fruit production per plant (0.26kg for 'Not

pruned' and 0.14kg for 'Pruned' treatment), the number of branches per plant (23 for

'Not pruned' and 16 for 'Pruned' treatment), the fruit ripening period (40-80 days), the

71


LAI development and the weather variables trends. It may be concluded that dry fruit

potential yields would have been around 400-450kg in 'Not pruned' treatment and

around 250-300kg in 'Pruned' treatment.

72

Table 3.1. Dry fruit production of J. curcas L. with two treatments:i)never pruned and in intercropping with A. pintoii (Not pruned), and ii)pruned two years before and in monoculture (Pruned), in MayaRanch, Belize, 2009.

Fruit Production Not pruned PrunedArea (m2) 1728 960# of plants 216 120Yield 2009.07.27 (kg) 37 7

kg*plant-1 0.17 0.06kg*ha-1 214 73

Yield 2009.08.10 (kg) 20 10kg*plant-1 0.09 0.08

kg*ha-1 116 104Total yield (kg) 57 17

kg*plant-1 0.26 0.14kg*ha-1 330 177

Figure 3.26. J. curcas L. dry fruit, dry seed and kernel total productions for 'Notpruned' and 'Pruned' treatments, in Maya Ranch, Belize, 2009. Jatropha plants weregrowing in intercropping with A. pintoii and have never been pruned ('Not pruned'treatment) or were growing in monoculture and have been pruned two years before('Pruned' treatment).

Not pruned Pruned

0

50

100

150

200

250

300

350

Total jatropha yield, Belize, 2009Maya Ranch trial

Fruit [kg*ha-1]

Seed [kg*ha-1]

Kernel [kg*ha-1]

[kg

*ha-

1]


Further measurements and calculations on the harvested yield have been undertaken to

establish dry matter assignment in the fruit. Seed to fruit ratio and kernel to seed ratio

73

Figure 3.27. J. curcas L. dry fruit, dry seed and kernel productions from 'Not pruned'treatment, represented by harvests on the 27th July and 10th August, in Maya Ranch,Belize, 2009. Jatropha plants were growing in intercropping with A. pintoii.

2009.07.27 2009.08.10

0

50

100

150

200

250

Jatropha yield from 'Not pruned' plot, Belize, 2009Maya Ranch trial

Fruit [kg*ha-1]

Seed [kg*ha-1]

Kernel [kg*ha-1]

[kg

*ha-

1]

Figure 3.28. J. curcas L. dry fruit, dry seed and kernel productions from 'Pruned'treatment, presented by harvests on the 27th July and 10th August, in Maya Ranch,Belize, 2009. Jatropha plants have been pruned two years before and were growingin monoculture without intercropping.

2009.07.27 2009.08.10

0

50

100

150

200

250

Jatropha yield from 'Pruned' plot, Belize, 2009Maya Ranch trial

Fruit [kg*ha-1]

Seed [kg*ha-1]

Kernel [kg*ha-1]

[kg

*ha-

1]


were calculated, separately per date and per treatment. On a dry matter basis, seed

weights were 70.5% to 74.3% of the dry fruit weight; while kernel weight was between

63% and 65% of the dry seed weight (Table 3.2).

A thousand dry fruit sample was randomly collected from the whole production of the

trial: seed dry matter was about 71% of dry fruit weight, which agreed with previous

measurements (Table 3.3). An average value 2.65 seeds per fruit was recorded (Table

3.4).

74

Table 3.2. Dry fruit weight, seed to fruit ratio and kernel to seed ratio of J. curcas L. in twotreatments: i)never pruned and in intercropping with A. pintoii ('Not pruned'), and ii) prunedtwo years before and in monoculture ('Pruned'), in Maya Ranch, Belize, 2009.

2009.07.27 2009.10.08 Total 2009Not pruned Pruned Not pruned Pruned Not pruned Pruned

Fruit (kg) 37 7 20 10 57 17Fruit sample (g) 740 140 400 200 1140 340

of which seed (g) 530 104 282 141 812 245Seed:Fruit (%) 71.62 74.29 70.5 70.5 71.23 72.06Seed sample (g) 100 100 100 100 200 200

of which kernel (g) 64 65 63 65 127 130Kernel:Seed (%) 64 65 63 65 63,5 65Fruit (kg*ha-1) 214 73 116 104 330 177Seed (kg*ha-1) 153 54 82 73 235 128

Table 3.3. J. curcas L. fruit coat to seed ratio, on a dry weight basis, fromone thousand dry fruit samples randomly collected in Maya Ranch, Belize,2009.

DRY ITEM QUANTITY (#) WEIGHT (g) (%)Fruits 1000 1681 100.00Coats 1000 485 28.85Seeds 2648 1196 71.15

Table 3.4. Number of seeds per fruit of J. curcas L., from onethousand dry fruit samples randomly collected in MayaRanch, Belize, 2009.

Number of fruits with: (#)4 seeds 23 or 2 seeds 9621 seed 36Average # of seeds*fruit-1 2.65


At Maya Ranch trial, further research was carried out to determine biomass

development by monitoring LAI and length of the effective branch. At the time of the

first survey, on September 1st, monitored plants were grouped according to their

management (Not pruned/Intercropping, Pruned/Monoculture or Not

pruned/Monoculture), showed LAI values between 0.7 and 0.8 for the

'Pruned/Monoculture' and the 'Not pruned/Intercropping' treatments, which were

significantly larger than the values of 'Not pruned/Monoculture' treatment (Figure 3.29);

although, this difference was not significant later on the season. LAI values were much

smaller (around 0.2; Figures 3.30, and 3.31) for the Not pruned/Monoculture treatment.

LAI values reported in Maya Ranch are altogether presented in Figure 3.32, where

management and date effect can be visually compared.

75

Figure 3.29. LAI measurements on J. curcas L. on September, 1st, in Maya Ranch,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.

Not pruned/Intercropping Pruned/Monoculture Not pruned/Monoculture

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9a

a

b

LAI measurements on jatropha, Belize, 2009September 1st - Maya Ranch trial

Management

LA

I [m

2*m

-2]


76

Figure 3.30. LAI measurements on J. curcas L. on November, 1st, in Maya Ranch,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

a

a

a

LAI measurements on jatropha, Belize, 2009November 1st - Maya Ranch trial

Management

LA

I [m

2*m

-2]

Figure 3.31. LAI measurements on J. curcas L. on December, 1st, in Maya Ranch,Belize, 2009. The same letters above the histograms indicate that between thetreatments significant differences were not found at the Duncan test, with P=0.01.


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

aa

a

LAI measurements on jatropha, Belize, 2009December 1st - Maya Ranch trial

Management

LA

I [m

2*m

-2]


Values of intercepted radiation by jatropha plants in Maya Ranch trial followed the

same trends discussed for the LAI. Solar radiation values are the same as for Warrie

Head, since they have been recorded in the same meteorological station. It is clear that

there is a considerable loss of solar radiation by jatropha in all the situations, over the

season (Figure 3.33; note the log scale). Similar management actions as discussed for

plantation at Warrie Head should be undertaken.

77

Figure 3.32. LAI measurements on J. curcas L. in Maya Ranch, Belize, 2009. Data arepresented in time series, according to the surveys over the season, occurred in September 1st,November 1st and December 1st. The same letters above the histograms indicate that betweenthe treatments significant differences were not found at the Duncan test, with P=0.01.


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9a

a

bb

b

b

bb b

LAI measurements on jatropha, Belize, 2009Time series - Maya Ranch trial

September

November

December

Management

LAI

[m2

*m-2

]


The lengths of the effective branch have been recorded twice during the season and

results showed values of 12cm to 18cm on November 1st and around 4cm on December

1st. However, treatments did not evidence statistically significant differences on

effective branch length, while differences appeared considering the date of survey

(except in the case of 'Pruned/Monoculture' plot).Overall, the longest effective branch of

'Not pruned/Monoculture' plot in November and the shortest of 'Not

pruned/Intercropping' plot in December have been pinpointed (Figure 3.34). In figure

3.35 the length of the effective branch in relation to the total length of the representative

branch is presented.

78

Figure 3.33. Solar radiation, LAI of jatropha under different treatments (managements: Notpruned/Intercropping, Pruned/Monoculture and Not pruned/Monoculture) and interceptedradiation are represented from September to December, in Maya Ranch, Belize, 2009.

S O N D S O N D S O N D

0.01

0.1

1

10

100

Solar radiation, jatropha LAI and Intercepted Radiation, Belize, 2009Maya Ranch trial


LAI [m2 m-2]

Intercepted radiation [kJ m -2 d-1]

Treatment (from left to right: Not Pruned/Intercropping, Pruned/Monoculture, Not Pruned/Monoculture)and month (September, October, November, December)


Regrettably, the survey could not be completed over the whole growing season, so the

growth curve for LAI and length of the effective branch can not be presented.

79

Figure 3.34. Length of the 'effective branch' (part of the branch with green leaveson), in J. curcas L., Maya Ranch, Belize, for November 1st and December 1st, 2009.The same letters above the histograms indicate that between the treatmentssignificant differences were not found at the Duncan test, with P=0.01.

Not pruned/IntercroppingPruned/Monoculture

Not pruned/Monoculture

0

4

8

12

16

20

ab abc

a

c bc bc

Jatropha 'effective branch' length, Belize, 2009Time series - Maya Ranch trial

2009.11.01

2009.12.01

Management

Effe

ctiv

e b

ran

ch [c

m]

Figure 3.35. Relative length of the 'effective branch' (part of the branch with greenleaves on) as percentage of the whole branch, in J. curcas L., Maya Ranch, Belize,for November 1st and December 1st, 2009.

Not pruned/IntercroppingPruned/Monoculture

Not pruned/Monoculture

0

5

10

15

20

25

30

35

40

Jatropha 'effective branch' relative length, Belize, 2009Maya Ranch trial

2009.11.01

2009.12.01

ManagementEffe

ctiv

e b

ran

ch a

s [%

] of t

ota

l bra

nch


It is noted that there is a sudden lowering of LAI values in the period September –

November, especially in 'Not pruned/Intercropping' and 'Pruned/Monoculture'

treatments; while in the period November – December LAI measured in the same

treatments is decreasing much slower, and even is increasing in 'Not

pruned/Monoculture' treatment, although differences are not significant. This fact can be

linked with the relatively low precipitation in October and a remarkable restart of the

rainfall in November and December. The additional information, provided by the length

of effective branch, suggest that between November and December the branch length in

which green leaves were growing was reduced but the leaf area did not vary, since

effective branch length decreased while LAI values kept being similar. Indeed, from

November to December, some leaves died thus reducing the space occupied on the

branch and some others leaves grew or in area or in number. Due to the favourable

precipitation events in November and December, jatropha might have developed and

increased the area of the already existing leaves or a new significant sprouting might

have occurred.

Observations in the two experimental sites (6 year old Maya Ranch and 1.25 year old

Warrie Head) lead to the following considerations. Results on biomass development

(LAI and effective branch) suggest that, even if the length of representative branch was

recorded to be greater in Warrie Head trial, jatropha plants in Maya Ranch had a

significantly larger LA and longer segments of branch with green leaves and more

branches. The reason for this is the different age, management (pruning and plant

density), genotype and degree of adaptation to the location; therefore, reasons of

different plant development should be cautiously studied.

3.4 Discussions

Field research in Belize allowed to monitor Jatropha curcas L. growth and development

under a wide range of conditions. Many different environmental variables have

influenced jatropha growth in the surveyed trials. Trials in Maya Ranch, Warrie Head,

80


Central Farm (and Bullet Tree) represent a wide range of different environmental factors

and differences in plant genotype, age, crop management (treatments: pruning,

intercropping, spacing), that unravelling the effects among these factors in jatropha

growth and development is challenging. At this point in time, after a relatively short

period of on field research, it is difficult to weigh the outputs and quantify the outcomes

of all the experiments considered. Last but not least, there may exist a difference in

weather variables that could not be specified per location, since the same meteorological

stations were used in the experimental sites. Some constraints were encountered and

scientific logic had to be developed in the process. Observations for the three trials with

possible comparisons are highlighted and specific actions on further research activity

are suggested.

As far as it is known, Belizean oldest jatropha plantation is located in Maya Ranch and

it has to be considered a valuable source of information. The present investigation

provides additional information to research previously undertaken in Maya Ranch. So

far, it looked like jatropha in Maya Ranch received a benefit from the intercropping with

Arachis. Not pruned plants might have larger biomass development, while pruned plants

keep both leaf and fruit production slightly delayed in the season: the reasons could be

that the plants still invest more biomass in new branches and have a more compact but

intense growth. Drought in October might have negatively affected leaves development,

but re-occurring rains in November restored the plants. Management actions, such as

weeding, could have influenced jatropha growth more, by eliminating those plants that

compete for resources and by leaving the vegetable material in the field, as organic

fertilizer. In general, the jatropha plantation at Maya Ranch is looked after with interest

and this potential could be valued even more, since a selection within the local genetic

resources could start from here. To follow this aim, production per single plant in a

defined production system need to be assessed, in order to start a selection that would

eventually lead to a breeding program. For this purpose, harvested seed should be

isolated per tree and number of fruits per inflorescence should be monitored. The seed

production reached in 2009 does not justify a commercial implementation of the crop.

81


Measures have to be undertaken in order to increase the production. An action to

improve crop production is making better use of the available space, that is to occupy

the inter- an intra-row space in order to give the plant a better chance of developing

lateral branches, bringing along the benefit of reducing weed growth; bending long

branches downward without breaking them could have a beneficial impact in order to

achieve the mentioned objective; also in this sense, knowledge in jatropha cultivation is

increasing and suggestions are made about yearly pruning in the dry season, setting

principal branches at about 50cm from the ground, leaving about 20cm of the original

branches and about 7-8 branches per plant (Stanningen, personal comm.). Moreover, it

has to be understood why, within the plot, some plants are weaker, smaller and were not

yielding; with regard to this, soil analysis are strongly recommended. After all, Maya

Ranch is an ideal place where to test different management actions on local genetic

material, so to analyse the responses and elaborate a jatropha cultivation decision-

support system.

The Warrie Head trial is set up with some of the considerations mentioned for Maya

Ranch, with a few exceptions. At Warrie Head, the plantation is five years younger and

three times bigger, and moreover it involves different genotypes and management

treatments. In general, LAI values measured in Warrie Head trial were, even at a double

plant density, about ten times smaller than the ones measured in Maya Ranch. Plant

spacing, at Warrie Head plantation, played a significant role in LAI development, with

the 'double-row' system being more efficient, even if plant architecture (single stem) of

both systems and genotypes did not appear the most efficient for optimized seed

production. Firm actions should be undertaken, i.e. start with pruning to induce

branching (Stanningen, personal comm.). The crop in Warrie Head might have suffered

from the drought in October, as well, and the response to the unexpected rains in

November was not so evident. For further investigations, consequences of intercropping

or application of effective microorganism should be analysed. Furthermore, the Cuban

accession (referred to as 'Cabo-Verde') should be surveyed, as 'Cabo Verde' is the most

productive accession to date in many areas. Further research could be implemented

82


since an irrigation system is available, where river water can be used to overcome water

shortage. At this point and time, TSDF together with the Energy and Environment

Partnership (EEP) is aiming to continue the research and the set up of a breeding

program should bring along beneficial consequences also in this situation. Further

investigations both in Warrie Head and Maya Ranch would necessarily have to deal

with the fact that plants were already in the ground and some factors would have to be

considered fixed; in any case the surrounding environment is promising and

expectations are high.

Adding knowledge and experience to current research is the jatropha plantation in

Central Farm, one of the latest pilot project set up in Belize, thanks to the ERA-ARD

transnational call. Results of the first three months of surveying, since its original

implementation, brought to considerations that should be discussed with similar trials

within the net. According to the data analysis, it seemed that the largest seeds, from

Guatemalan accession G17, resulting in a considerable germination rate, gave also the

largest amount of biomass in seedlings. The low-toxic accession from Mexico and the

local accession from Belize showed different germination patterns, but eventual

biomass development did not differ significantly. Mexican low-toxic accession seemed

to have a superior germination power resulting in the highest germination rate and a

discrete degree of adaptation for its greater increase in LA between the two dates of

survey. Belizean local accession, instead, showed satisfying patterns of germination,

growth and development, although considered average when compared to the other two

accessions. A selection of plant material should be done as the next step in developing

Belize jatropha scenario. Hopefully, the project outputs will contribute to a beneficial

application of jatropha system in Belize and worldwide. A summary of results of this

work is reported in the column 'Research in Belize', in tables a,b,c and d of annex 1.

83

4. Conclusions

Energy demand and environmental awareness are pushing world community to search

for alternatives to fossil fuels, both in developing and developed countries. With regard

to this search for alternatives, a significant question is emerging about new energy

source, what choice should at the same time mitigate global warming, reduce oil

dependence, and, possibly, improve quality of life globally. Thence, numerous solutions

to face energy hunger worldwide, without compromising the health of the planet, seem

available nowadays and may vary according to regional peculiarities. In fact, issues,

such as food security, land property and division, technology availability, market

competition, social disparity and natural constraints among others, might affect local

and regional decision-making processes towards selection and definition of a

sustainable energy system. In this sense, comprehensive policies are strongly

recommended to initiate such sustainable energy process, together with the

implementation of research and development projects on new suitable energy sources.

The present research investigated the cultivation of Jatropha curcas L., as one of the

potential candidate crops as renewable energy source in Belize is, indeed, jatropha

vegetable oil. This crop appears to be a suitable and valuable option to meet the needs

of the country because of its remarkable features. Findings and challenges that the start

up of a jatropha based bioenergy system would bring are hereunder discussed.

The implementation of jatropha cultivation in Belize is an opportunity because of the

following good reasons. Jatropha is native to Belize, and researches suggested genetic

resources availability and a proper pedoclimatic situation for its growth and

development in the country. Moreover, land is available and the integration of jatropha

in existing farming systems (especially intercropping and agro-forestry systems) or its

use as hedge seem feasible and helpful, as its cultivation is easy to implement at a

small-farm scale and low technology inputs are required. In fact, being a perennial

drought tolerant energy crop brings to a series of positive patterns, even at low seed

production levels: there are no needs for fulfilment of annual agricultural practices that

often require appropriate machinery and structures (e.g. tillage, sowing); it withstand the

possibility of one or more years of interruption of cultivation for climatic or human

reasons; its cultivation provides valuable co-products such as leaves,latex, fruits coats,

4.Conclusions

seed cake and shells for medicinal uses, fertilizers, insecticides, soap production or

combustibles, as well, according to researchers' judgements and findings in similar

agro-ecological zones (Baldrati, 1950; Heller, 1996; Rijssenbeek and Togola, 2007;

Kumar and Sharma, 2008; Jongschaap et al., 2007; Achten et al., 2008; Ogunwole et

al., 2008). Low technology inputs are required on the cultivation step ,where most of

the management actions are done manually (pruning and harvesting, mainly), and on oil

processing. In fact, BD20 blends (20% of vegetable oil and 80% of diesel) are possible

and, after all, would greatly reduce Country costs for energy.

In Belize, interests on jatropha have been shown at local national and regional levels. In

the Country, the Ministry of Agriculture is going to start up a five acre jatropha pilot

plantation to optimize the agro-technology and bring it to farmers (Martinez, personal

comm.); private investors are increasing since few years, both for research purposes and

commercial activity set up; the NGO Tropical Studies and Development Foundation

Belize is conducting research projects together with the Energy and Environment

Partnership (EEP), the Organization of the American State (OAS), the ERA-ARD net,

and its role as pioneer on jatropha research throughout the Country is remarkable. At

regional level, Central America and Caribbean Countries are cooperating and pushing

for a concrete development of bioenergy regulations and for a deep technology research.

Particularly, Belize, represented by the Ministry of Agriculture, the University of Belize

and TSDF, signed a Memorandum of Understanding, planning further collaboration and

research together with Colombia, Costa Rica, El Salvador, Guatemala, Honduras,

Mexico, Nicaragua, Panama and Dominican Republic at the 'First Reunion of the

Biofuels Research and Development Network' of the Mesoamerican Project (Primera

Reunión de la Red Mesoamericana de Investigación y desarrollo en Biocombustibles,

23-27 de Agosto, 2009, Tuxtla-Gutierrez, Chiapas, México). With regard to this,

institutional strengthening at national and regional scale is recommended, and, in

Belize, the creation of a platform to host highly scientific researches and knowledge

exchange would be very welcome.

Next steps that would allow to unravel jatropha potentials in Belize include: the

86

4.Conclusions

selection of high-yielding individuals and the set up of a breeding programme;

feasibility studies of jatropha cultivation in different Districts; regulation of bioenergy

sector, to promote the birth of an equitable market for jatropha and other bioenergy

products. What is more, the existing knowledge should be integrate with next findings

and the wide range of possibilities linked to a jatropha production system should be

shared with farmers and growers associations. Ultimately, as motivating the first actors

(the farmers) in this value chain is essential, possibilities should be exhaustively

investigated both on developing agro-forestry applications suitable in Clean

Development Mechanism projects or other rural development and bioenergy projects

and, what is more, oil extraction and processing technology should be brought and

developed in Belize.

87

5. Acknowledgements

All around the world, many friends and tutors I met along the road and I thank them all

for helping and talking and walking with me to the slopes of the mountain. My sincere

gratitude goes to Sylvia and Alex Laasner and TSDF Belize, who welcomed me from

the very beginning until the last day, providing the basic equipment to carry out the

research activity in the field and in the office and indicating me the borderline between

the 'endless research' and the implementation of research findings into concrete actions;

to Michael Rosberg, Marion Cayetano and Sylvia Carillo from Galen University, who

stimulate a debate on jatropha (and helped me getting the visa); to Dr. Holder, Dr.

Mendez and Maynor Hernandez from University of Belize, for their essential

collaboration; to Ann Gordon and Michelle Smith of the National Meteorological and

Hydrological service for their most valuable contribution in providing all the climatic

data; to Eva, Toby, Alan and all TSDF team, who could translate theory to practice,

implementing the experimental design so efficiently; to the Mexican Secretary of

Foreign Affairs and to COCyTECH and the State of Chiapas, Mexico, who permitted to

bring the debate on bioenergy and jatropha at international level, fostering cooperation

and knowledge exchange between Central American States, during the First Reunion of

the Mesoamerican Network on Biofuels Research and Development in Tuxtla-Gutierrez,

Chiapas; to Pio Saki from the University of Belize and to Clifford Martinez from

Belizean Ministry of Agriculture, who joined me, as TSDF representative, and

represented Belize in that reunion; to Hans Stanningen, for sharing his knowledge on

jatropha cultivation; to John and Richard, to the friends of 6, Bladen street, especially

Mrs Flores and her familiy and, the best chess player, nurse Robert John Ilao, to take

care of me and make my experience in Belize more sustainable. Some friends, in Belize,

are pictured in figures 5.1, 5.2, 5.4 and 5.3.

I thank professor Berti, for the valuable contribution on structuring the statistical

analysis of this thesis.

My gratitude also goes to my friends and my family in Italy, to Papà, who stimulates a

critic dialogue on agriculture, together with Diego and my friends of studies Mariano,

Lorenzo, Marco, Alvise, Alessandro, Giulio and Linda; to Mamma, Clara, Nicola,

5.Acknowledgements

Maria, Girolamo and all the members of my family to support (and 'sopport') me until

here, especially Zia Agnese, who taught me the first steps in the world of Research, and

Zia Lavinia, who constantly stimulate my research and interests forwarding me

agricultural information and news on jatropha. I thank my grandparents Nonna Paola

and Nonno Berardo, Nonna Clara and Nonno Beppi, for their best lessons of life, being

the most precious model I have ever known. Last but not least, I thank Valentina, for

patiently reviewing drafts of this M.Sc. thesis, finding better expressions, being an

outsider, and for showing me the power of love.

I apologize if I missed someone but I guarantee: I did not forget anyone.

90

Figure 5.2. Transplanting jatropha with Toby,Alan and TSDF team, in Central Farm,Belize, November 2009.

Figure 5.1. Harvesting with Rubelio and histwo brothers, in Maya Ranch, Belize, July2009.

Figure 5.4. Surveying jatropha plantations,with Hans Stanningen and Toby Sengfelder,Cayo District, Belize, October, 2009.

Figure 5.3. Surveying jatrophaplantations, with RaymondJongschaap, Cayo District,Belize, October, 2009

Annex 1. Growth parameters and sustainabilityindicators tables

Annex 1a. Growth parameters by plant part

(continues in the next page)

Growth Parameter Unit or evaluating pm Measurement Lite rature ResearchSEED in Belize

Seed germinability % Kaushik et al., 2007 80-96Seed germination energy days to germination 10 Henning, 2007Seed yield (dry seed) t*ha-1*yr-1 1.5-7.8 Jongschaap et al., 2007Seed size length (cm) 1-2 Henning, 2007 1.8-1.9

width (cm) 1-1.1HI-seed kg*kg-1 0,35 Jongschaap et al., 2007100-seed weight g 63 Singh et al., 2008 54-731000-seed weight g 400-730 Henning, 2007Shell:Kernel ratio by DM % 34.3:65.7 Openshaw, 2000; Singh et al., 2008 33-37:63-67Oil content in seed % 33.6-37.0 Rivera Lorca and Ku Vera, 1997Oil content in kernel % 21-74 Shah et al., 2005Oil yield l*ha-1 439-2.217 Jongschaap et al., 2007HI-oil l*kg-1 0,1 Jongschaap et al., 2007Oil quality Different compounds and composition Henning, 2007; Jongschaap and van Loo, 2009DMA-seed % 32 Jongschaap (personal comm.)DMA-shell % 11 Jongschaap (personal comm.)DMA-kernel % 21 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007

ROOT# roots*plant-1 n Kaushik et al., 2007Length (aft. 90 days) cm 10-17 Kaushik et al., 2007Root hairs yes/noExplored area by roots cm³Water uptake mm*ha-1Nutrient uptake (NPK) kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Mychorrization (after inoculation) yes/no yes Jongschaap et al., 2007DMA % 8 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007

STEM/WOODCuttings survival rate (T,M,B) % 42-72-88 Achten et al., 2008Seedling survival rate % 95-100 Kaushik et al., 2007Total height (aft. 90 days) cm 29-47 Kaushik et al., 2007Total height m 1.15-1.34 Kaushik et al., 2007Collar diameter (aft. 90 days) cm 8-11 Kaushik et al., 2007Crown size m 1.25-1.52 Kaushik et al., 2007

n 25 Henning, 2007Apical dominance low/highDMA % 23 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007

LEAF# leaves*plant-1 (aft. 90 days) n 13-20 Kaushik et al., 2007Leaf size length (cm) 7-18 Henning, 2007

width (cm) 5.5-18 Henning, 2007LA m²leaf*plant-1Light interception k 0.55-0.68-0.75Clorophyll content SPAD values existing data Jongschaap (unpublished data)PET, AET mm*day-1Photosyntetic activity existing data Jongschaap (unpublished data)DMA % 23 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007

FLOWER# male flowers*plant-1 n# female flowers*plant-1 nMale:female ratio n 13:1, 29:1 Achten et al., 2008Location of flowers Female major axis, male lateral, branch age Henning, 2007Cross:self-pollinated Abdelgadir et al., 2008Pollination actors Moths yes(/no) Henning, 2007

Honeybees yes(/no) Abdelgadir et al., 2008Small flower and abortion % up to 60 Jongschaap et al., 2007

FRUIT# fruits*plant-1 n 24-240# fruits*branch-1 n 3-8Fruit size length (cm) 2.5 Singh et al., 2008Fruit setting %Ripening days 90Coat:Seed ratio by DM n 30:70 Openshaw, 2000 29:71HI-fruit kg*kg-1 0.50 Jongschaap et al., 2007DMA % 46 Jongschaap (personal comm.)DMA-coat % 14 Jongschaap (personal comm.)Nutrient composition (NPK, …) % existing data Jongschaap et al., 2007

89 (a)7-14 (a)

0.13-0.24 (b)

8-16 (j)19-25 (c)

17-20 (c)0.5-2.5 (d); 2-4 (e)

# branches*plant-1 (optimum) 1-4 (d); 11-40 (e)Montes et al., 2008 (f)

1-5 (c)

0.02-0.9 (k)Jongschaap (unpublished data) (g)

Annex 1. Growth parameters and sustainability indicators tables

(a) The value may vary according to different pre-treatments.

(b) Data not fully reliable for Belize (see section 3.2).

(c) 60 days after sowing.

(d) 1 year old plantation.

(e) 6 years old plantation.

(f) It is reported variability in plant architecture among different accessions.

(g) 'k' varies according to LAI values, respectively >7; 7>LAI>1,5; <1,5.

(h) Plant breeding still in its infancy.

(i) Calculated on Minimum and Maximum monthly values in the growing season (June – December 2009).

(j) At different planting times.

(k) According to plant age and period during the growing season.

94

PLANT Growth Parameter Unit or evaluating pm Measurement Lit erature in BelizePlant energy efficiencyNutrient cycles (macro/micro) Chaudary et al., 2008Plant potential lifespan years 30-50 Henning, 2007

GenotypeFitness (h)

HormonsQualityQuantityLocation in plant organs

Stress toleranceAbiotic Temperature (optimum) °C 20-28 Achten et al., 2 008;

Rainfall (optimum) mm*ha-1*yr-1 1000-1500 Daey Ouwens et al., 2007 1476R.U. %

RadiationVapour pressure kPaWind speed m*s-1

Biotic Pest (types) Phytophagous, powdery mildew; more Henning, 2007; Daey Ouwens et al., 2007Disease (types and plant organ) Cassava mosaic virus; more Henning, 2007; Daey Ouwens et al., 2007Nutrient competitionWater competitionEnergy competition

20-33 (i)

kJ*m-2*d-1 12-17 (i)28-32 (i)4-6 (i)

Annex 1b. Growth parameters by crop system

(a) It should always be specified for a complete understanding of following data.

CROP SYSTEMGrowth Parameter Unit or evaluating pm Measurement Lit erature Research

Monoculture in Belizeplants*ha-1 1100-2500 Heller, 1996; Henning, 2007 1250-2500

Light interception radiation intercepted*m-2Energy use efficiencyLAICanopy size m³Total aerial biomass kg*ha-1Root system development kg*ha-1

m³*plantSeed yield (dry seed) kg*ha-1HI-seedWater uptake mm*ha-1PET, AET mm*ha-1*day-1Water use efficiencyNutrient uptake (NPK) kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Plant potential lifespan yearsInteractions with neighbour plants Effects

Intercroppingplants*ha-1

Light interceptionEnergy use efficiencyLAICanopy size m³Total aerial biomass kg*ha-1Root system development kg*ha-1


Living fenceplants*ha-1

Light interceptionEnergy use efficiencyLAICanopy size m³Total aerial biomass kg*ha-1Root system development kg*ha-1


Plant density (a)

Plant density (a)

Plant density (a)

Annex 1c. Sustainability indicators by sphere of interest

Sustainability indicators Unit or evaluating pm Measu rement Literature ResearchCrop energy balance (input:output) 1:4-5 Henning, 2007 in Belize

AGRONOMICSoil

Structure macro-aggr stab. + 6-30% Chaudhary et al., 2007soil bulk density - 20% Ogunwole et al., 2007

OM contentMicrobial activityMicrobial diversitySoil moisture retention increased Kumar and Sharma, 2008Erosion controlOn farm use of by-products yes/no yesNutrient cycles (NPK) kg*ha-1*yr-1 Jongschaap (personal comm.)

WaterPlant water use efficiency (seeds) kg*m-3 0.615-1.314 Abdrabbo and Atta, 2008Plant water use efficiency (oil) kg*m-3 0.154-0.393 Abdrabbo and Atta, 2008Actual water use no data Jongschaap et al., 2007Water pollutionNutrient cycles

AirNutrient cycles

ENVIRONMENTALSoil

Soil recovery Spaan et al., 2004; Kumar et al., 2008)Soil preservation Spaan et al., 2004Biodiversity (macro/micro-flora/fauna) # species*m²Acidification g SO4²--eq*ha-1*yr-1 no data IFEU Institute, 2008

WaterWater consumption l*week-1*plant-1 Abdrabbo and Atta, 2008Groundwater leaching g NO3-*ha-1*yr-1Eutrophication g P2O5-eq*ha-1*yr-1 no data IFEU Institute, 2008

AirGHG emission kg CO2-eq 56,7 Prueksakorn and Gheewala, 2006GHG emission balance neutralCarbon sequestration g CO2*ha-1*yr-1

ECONOMICLabour cost $*man-1*d-1 10-15USDIncome generation $*kg-1By-products $*kg-1Fossil fuel independence $Renewable energy production $*J-1

SOCIALDiversify agr. activity # agr. activitiesLabour generation man*day-1*ha-1

Annex 1d. Sustainability indicators by crop system

CROP SYSTEMSustainability indicators Unit or evaluating pm Measu rement Literature Research

Monoculture in BelizeEnergy Input l of petrol*ha-1

Output eq-l of petrol*ha-1Water Input (irrigation) mm*ha-1*yr-1

Consumption mm*ha-1*yr-1Nutrient Nutrient input (NPK, …) kg*ha-1*yr-1

Nutrient Removed kg*ha-1*yr-1 existing data Jongschaap (personal comm.)Others Foreign molecules input (ie:pesticide) kg*ha-1*yr-1

Amendments input kg*ha-1*yr-1On farm use of by-products from JC PS kg*ha-1*yr-1Labour input man*day-1*ha-1Interactions with neighbour plants Effects

IntercroppingEnergy Input l of petrol*ha-1





Living fenceEnergy Input l of petrol*ha-1





Annex 2. Experimental designs

Table a. Maya Ranch trial yield design.

A B C D E F G HNot pruned o o o o o o o o 1

o o o o o o o o 2o o o o o o o o 3o o o o o o o o 4o o o o o o o o 5o o o o o o o o 6o o o o o o o o 7o o o o o o o o 8o o o o o o o o 9o o o o o o o o 10o o o o o o o o 11o o o o o o o o 12o o o o o o o o 13o o o o o o o o 14o o o o o o o o 15o o o o o o o o 16o o o o o o o o 17o o o o o o o o 18o o o o o o o o 19o o o o o o o o 20o o o o o o o o 21o o o o o o o o 22o o o o o o o o 23o o o o o o o o 24o o o o o o o o 25o o o o o o o o 26o o o o o o o 27o o o o o o o 28o o o o o o o 29o o o o o o o 30o o o o o o o 31o o o o o o o 32o o o o o o o 33o o o o o o 34o o o o o o 35

o o o o o 36o o o 37o o o 38

Pruned o o o o o o o o 39o o o o o o o o 40o o o o o o o o 41o o o o o o o o 42o o o o o o o o 43o o o o o o o o 44o o o o o o o o 45o o o o o o o o 46o o o o o o o o 47o o o o o o o o 48o o o o o o o o 49o o o o o o o o 50o o o o o o o o 51o o o o o o o o 52o o o o o o o o 53o o o o o o o o 54o o o o o o o o 55o o o o o o o o 56o o o o o o o o 57o o o o o o o o 58o o o o o 59

Not yielding o o o o o 60o o o 61o o o 62o o o 63o o o 64o o o 65

o o 66

Table b. Maya Ranch trial LAI design

A B C D E F G H1

Block 1 2 Not pruned,3 Monoculture

Not pruned, 456789

10111213

Block 2 141516171819202122232425

Block 3 2627282930313233343536373839

Block 1 4041

Pruned, 4243444546

Block 2 47484950515253

Block 3 54555657585960616263646566

o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o o

Intercropping o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o oo o o o o o

o o o o oo o oo o o

o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o o

Intercropping o o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o oo o o o oo o oo o oo o oo o oo o o

o o

7 6 5 4 3 2 CA 7 6 5 4 3 2 GA53 57 55 52 51 52 50 51 49 51 46 48 45 38

o o o

oo

oo o

oo o

o oo o o o

o o o oo o o o o

o o o o oo o o o o o o

o o o o oo o o o o o o o o

o o o o o o o oo o o o o o o o o o

o o o o o o o oo o o o o o o o

o o o o o o o o o o o oo o o o o o o o o o o oo o o o o o o o o o o o

o o o o o o o o o o o o o oo o o o o o o o o o o o o

o o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o o oo o o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o o oo o o o o o o o o oo o o o o o o o oo o o o o o o o oo o o o o o o o oo o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o oo o o o oo o o o oo o o o oo o o oo o oo o oo oo o

o

Table c. Warrie Head trial design

4 3 2 GB 4 3 2 CB95 98 99 99 94 98 100 95

GB: Guatemala,4*1mCB: Cuba, 4*1mCA: Cuba, (3*1,7)*1,7mGA: Guatemala, ( 3*1,7)*1,7

o

o oo o

o o oo o

o o oo o o o

o o oo o o

o oo o o o

o o o o o oo o o o o

o o o o oo o o o o oo o o oo o o o o

o o o o oo o o o

o o o o o o oo o o o o o oo o o o o o o o

o o o o oo o o o o o o

o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o o

o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o o oo o o o o o oo o o o o o oo o o o o o oo o o o o oo o o o o oo o o o o oo o o o oo o o o oo o o o oo o o oo o o oo o o oo o oo o oo o oo oo oo oo

Table d. Central Farm trial design (1/2)

ERA-ARD Biofuels in Africa and Central America 2009 -2013 – Planting Plan 26 November 2009Gradient >>>

Block I Block II Block III

01 o o o o o o 02 o o o o o o 13 o o o o o o 14 o o o 25 o o o o o o 26 o o o 01

o o a o b o o o o a o b o o o o a o b o o o a b o o o a o b o o o a b o

o o c o d o o o o c o d o o o o c o d o o o c d o o o c o d o o o c d o

o o e o f o o o o e o f o o o o e o f o o o e f o o o e o f o o o e f o 02

o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o

03 o o o o o o 04 o o o 15 o o o o o o 16 o o o 27 o o o o o o 28 o o o o o o 03

o o a o b o o o a b o o o a o b o o o a b o o o a o b o o o o a o b o o

o o c o d o o o c d o o o c o d o o o c d o o o c o d o o o o c o d o o

o o e o f o o o e f o o o e o f o o o e f o o o e o f o o o o e o f o o 04


05 o o o 06 o o o o o o 17 o o o 18 o o o 29 o o o o o o 30 o o o 05

o a b o o o a o b o o o a b o o a b o o o a o b o o o a b o

o c d o o o c o d o o o c d o o c d o o o c o d o o o c d o

o e f o o o e o f o o o e f o o e f o o o e o f o o o e f o 06

o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o

07 o o o o o o 08 o o o 19 o o o o o o 20 o o o o o o 31 o o o o o o 32 o o o 07

o o a o b o o o a b o o o a o b o o o o a o b o o o o a o b o o o a b o 111m

o o c o d o o o c d o o o c o d o o o o c o d o o o o c o d o o o c d o

o o e o f o o o e f o o o e o f o o o o e o f o o o o e o f o o o e f o 08


09 o o o o o o 10 o o o 21 o o o 22 o o o 33 o o o 34 o o o 09

o o a o b o o o a b o o a b o o a b o o a b o o a b o

o o c o d o o o c d o o c d o o c d o o c d o o c d o

o o e o f o o o e f o o e f o o e f o o e f o o e f o 10

o o o o o o o o o o o o o o o o o o o o o o o o o o o

11 o o o 12 o o o 23 o o o o o o 24 o o o o o o 35 o o o o o o 36 o o o 11

o a b o o a b o o o a o b o o o o a o b o o o o a o b o o o a b o

o c d o o c d o o o c o d o o o o c o d o o o o c o d o o o c d o

o e f o o e f o o o e o f o o o o e o f o o o o e o f o o o e f o 12

o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o

24 23 22 21 20 19 18 17 16 15 14 13

52m

Table e. Central Farm trial design (2/2)

Row D1 D2

G1 Mexico accession 3,7 2,2 1,1 m I1 No Intercropping Intercrop: Arachis pintoii

G2 Belize accession 3,7 2,2 1,1 m Jatropha curcas O Border row plant

G3 Guatemala accession 3,7 2,2 1,1 m I2 Intercropping X Monitoring plant

1250 2500 trees ha-1

Treatments G D I Treatment randomization plots

1 1 1 1 11 3 12 5 8 2

2 1 1 2 7 5 11 1 12 4

3 1 2 1 2 8 9 6 7 10

4 1 2 2 12 1 3 4 11 6

5 2 1 1 4 6 2 10 5 1

6 2 1 2 9 10 8 7 3 9

7 2 2 1

8 2 2 2 Treatment randomization horizontal hedge (left to r ight)

9 3 1 1 1 8 12 6 4 7 3 9 11 5 2 10

10 3 1 2

11 3 2 1 Treatment randomization horizontal hedge (top to bo ttom)

12 3 2 2 1 6 10 8 4 7 11 2 12 5 3 9

Plots row plants plants plot-1 Plants for plots Field size (m2) 6440 m2

Plants per plot D1 5 4 20 18 plots x 20 plants 360

D2 5 7 35 18 plots x 35 plants 630 990 plants

Living fence D1 D2 Plants per fence Plants per treatment unit in fence

Field length 111 m 0,25 0,50 m 55,5 m / 0.25 + 55,5 m / 0.5 = 333 D1 37

Field width 52 m 0,25 0,50 m 26 m / 0.25 + 26 m / 0.5 = 156 489 plants D2 19

Distance fence from other plots Total plants 1479 plants

At least 3,7 m

Additional plants: 255

19m

103,6m o o o o o o o o o o o o o o o

o o o o o o o o o o o o o o o


o o o o o o o o o o o o o o





o o o o o o o

o o o o o o o

o o o o o o o

o o o o o o o

o o o o o o

o o o o o o

o o o o o o

o o o o o o

o o o o o o

o o o o o o o o o o o

o o o o o o o o o o

o o o o o o o o o o

o o o o o o o o o

o o o o o o o o o

o o o o o o o o o

o o o o o

o o o o o

o o o o o

o o o o

103,6m o o o o9m

Table f. Extra land (above and right) for additional plants atCentral Farm

Additional plants: 240




o o o o o o o o o o o o o o o o o o o o o o o o o o o 38m


o o o o o o o o o o o o o o o o o o o o o





38 m

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If you use information from this M.Sc. dissertation document, please citeand refer to:

da Schio, B., 2010. Jatropha curcas L., a potential bioenergy crop. On fieldresearch in Belize. M.Sc. dissertation. Padua University, Italy and Wageningen University and Research centre, Plant ResearchInternational, the Netherlands.

jatropha curcas l.: a potential bioenergy crop - on field research in belize

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