horticulture division technical annual report · 2016-04-14 · management techniques for cashew 59...

1

TECHNICAL BULLETINNO.

HORTICULTUREDIVISION TECHNICAL

ANNUAL REPORT1995 - 1996

2CONTENTS

Preface 1Horticulture Division Staff 5Location Details 7FRUITS PROGRAMMango Research in Central Australia 8Variation in Mango Production 12Mango Postharvest Research 14Daily Temperatures to Predict Harvest Date of Mangoes 18Effect of Pre-flowering Soil Moisture and Cultar on Flowering, FruitSet and Yield of Kensignton Pride Mangoes 20Industry Development and Support - Bananas 22Banana Nutrient Monitoring 24Banana Cultivar Assessment 28Effect of Irrigation Rate on Banana Growth and Yield 29Durian Cultivar Identification, Flowering and Pollination Studies 31Rambutan Mulching Trial 33Rambutan Pruning Trial 35Rambutan, Mangosteen and Durian Industry Strategic Plan 37Rambutan Fruit Browning and Packaging 39Rambutan Phenology and Nutrition 39Assessment of Red Flesh and Other Recently Introduced GrapefruitCultivars in Central Australia 41Evaluation of a Range of Stonefruit Types and Cultivars on Peach- Almond Hybrid Rootstock for Commercial Production 42Evaluation of a Range of Bunch Covers to Reduce Rain Damage in Dates 43Date Cultivar Evaluation 44Comparison of Imported Tissue Cultured and Offshoot Date Palms 45Date Germplasm Collection at the Arid Zone Research Institute 46Parlatoria Scale Eradication 48Evaluation of the Effect of Combine® on Bunch Quality in Tablegrapes 49Using Chemical Treatments to Break Grapevine Dormancy 51Rockmelon and Honeydew Trials in the Top End 53Cashew Breeding Line Assessment 58Management Techniques for Cashew 59Mastotermes Research in Katherine 60Bamboo Research 62Evaluation of Bamboo Variety Considered Suitable for Culinary, Wind Break and Timber Purposes 64VEGETABLES AND ORNAMENTALS PROGRAMEvaluation of the Potential of Centralian Native Species as Cutflowers 64VISITORS TO HORTICULTURAL RESEARCH ESTABLISHMENTS 65SEMINARS, WORKSHOPS AND FIELD DAYS 67PUBLICATIONS 70

3PREFACE

All Divisions within the Department are now organised along a number of programs,with cross-divisional interaction. The practice of preparing Business Plans continuesto stream line activities of the Department in assisting industry development. Areview has been undertaken of the policy for the management of the Department’sresearch and development programs. The revised arrangements now in placeemphasise the matching of projects to strategic issues known to be of importance toindustry.

Horticulture has experienced sustained growth over several years. Although the mostrecent mango season was unfavourable, the value of the crop increased by almost25%. The total value of horticulture, including the nursery and cut flower industry in1995 was approximately $44.7M, a 13.7% increase on the previous year. Continuingstrong growth in anticipated as the two large banana plantations being established atLambells Lagoon expand production and achieve a significant position in the overallAustralian industry.

The purpose of this report is unchanged, with an objective of presenting all the workdone in the past year by Horticulture Division staff in the NT. Work reported herewill be organised into the Division’s Program structure as detailed below:

FRUITS PROGRAMObjective: To improve the sustainability and expansion of commercial fruit

production.

Sub-Program Co-ordinatorMango: Dr V KulkarniBanana: Mr K BlackburnTable Grapes: Mr G KennaTropical Exotics Dr T K LimDates Mr G KennaCitrus Mr M HoultSub-Tropicals Mr G KennaCashew Dr V Kulkarni

VEGETABLES AND ORNAMENTALS PROGRAMObjective: To enhance the profitability and sustainability of vegetable and

ornamental production in the horticulture industry.

Sub-Program Co-ordinatorAnnual Crops Mr M SmithAsparagus Mr M SmithTropicals Mr J PowellAustralian Natives Mr G Kenna

4

Table 1: Trends in production, value and price of mango, banana and tablegrapes in the past 5 years.

1991 1992 1993 1994 1995MANGOProduction (Tons) 1984 3984 3810 5715 5598Value ($M) 6.15 10.92 13.73 15.83 19.67Average Price ($/Kg) 3.10 2.75 3.61 2.77 3.51

BANANAProduction (Tons) 1790 2800 2381 3154 2957Value ($M) 2.22 3.47 2.62 3.56 2.973Average Price ($/Kg) 1.24 1.24 1.10 1.13 1.01

TABLE GRAPESProduction (Tons) 811 1310 1149 1130 1600Value ($M) 2.36 4.54 4.42 4.63 6.40Average Price ($/Kg) 2.91 3.47 3.84 4.10 4.00

Whilst the value and production figures for banana production decreased slightly thisyear (by 6%), the future for bananas in the NT looks promising with the establishmentof two major banana growers, with 100 ha of bananas each, to be planted over thenext 2-3 years.

The value of table grapes this year increased by more than 38% to $6.4M. Productionwas also higher this year, with 470 tons more than last year..

Vegetable production this year increased by more than 16% compared to 1994 as lastyear as illustrated in Table 2.

Table 2: Production and value of fruit and vegetables for 1994 and 1995CROP PRODUCTION (Tons) VALUE ($M)

1994 1995 1994 1995FRUITS

Mango 5715 5598 15.831 19.671Melons 2715 2633 2.935 2.916Table Grapes 1130 1600 4.625 6.400Banana 3154 2957 3.562

2.973Others 447 768 2.088 2.184Sub-Total 13197 13556 29.041 34.144

VEGETABLESAsian Veges 251 678 0.525 1.718Cucurbits 1179 1248 1.173 1.021Others 1209 682 1.988 1.272Sub-Total 2639 2608 3.686 4.011

TOTAL FRUIT 15836 16164 32.727 38.155& VEGETABLES

The Asian vegetable industry is developing into a significant part of NT Horticulture.The data presented in Table 2 is incomplete as most of the trade is vertically

5integrated and goes into southern retail markets, without going through traditionalmarketing chains. This presents a problem in obtaining all the relevant data.

The accurate value of cut-flowers and other nursery industry production is alsodifficult to obtain. There is a definite increase with this industry and an estimate of$8.0-$10.0M is provided for this sector this year.

HIGHLIGHTS FOR THE YEAR

• During the past three years the Division has made a special effort to presentindustry with recent results from various sub-programs. During the year, therewere six presentations to address various industry sectors in the Darwin,Katherine and Alice Springs regions. Most of these presentations were wellattended by industry and useful feedback was received, which will assist withfuture planning.

• The Division organised a review of R&D in various sub-programs, listed in theDivision’s Business Plan. This process, along with the industry input listed above,will improve future program delivery to address industry issues.

• The Division assisted the banana industry in monitoring and evaluating the qualityof bananas supplied to various retail outlets in the Darwin area.

• The Division provided assistance to cutflower growers in the Alice Springs regionin direct export of native cutflowers to Japanese markets through the ClassicJapan marketing group.

• The Lambells Lagoon area, where citrus canker was identified in the early 1990’s,was declared free of this disease, after an intensive two year monitoring period.This now clears all of the NT from citrus canker quarantine restrictions.

• The Citrus Industry Review initiated last year was completed by the consultants.The report was presented to industry and the potential of developing red-fleshgrapefruit, summer lemons, pomelo and limited quantities of mandarin, limes andoranges was identified. This report will be used as a basis for assisting thedevelopment of the citrus industry in the NT. The first year of cropping in thecitrus research orchard at Katherine Research Station clearly demonstrated thehigh quality of super red grapefruit, the very early maturity times for mandarinsand the high quality and early maturity time for lemons during the summer period.

• The Division continued to participate in the National Mango Breeding Project, incollaboration with WA and Queensland State Departments and CSIRO, toimprove mango varieties for the Australian Industry. To date, some 750 hybridshave been generated collectively by all participants. These hybrids will be plantedin Queensland and the NT for further evaluation.

• First year results in the externally funded asparagus droughting projectdemonstrated the dramatic influence of droughting on spear quality and yield. Thecurrent commercial practice, of withholding irrigation for 6 weeks prior to harvestto induce dormancy, was shown to significantly limit both spear production andquality. However a short period of moisture stress was shown to be better thankeeping the crop well irrigated.

• The Division continued to employ a translator to assist a number of Vietnamesegrowers with pest control, pesticide application and other production issues.

• The Division set up an 'Exotic Pest Working Group' with industry representation,to formulate strategies to effectively deal with future incursions of insect anddisease problems.

• Through the Division's active participation, a number of areas for horticulturaldevelopment were released at Lambells Lagoon. Two large banana growers haveplanted significant areas and in two years are expected to treble the area under

6banana production in the NT. A new melon grower and a large asparagusgrower are expected to develop these crops in the NT in the coming year.

• With the Division’s participation, the Wildman River area (some 27,000 ha) wascompulsorily acquired from Wildman River Cashew Plantations, after theydefaulted on promised development. This land will now be sub-divided and madeavailable for developing cashews and other crops by a number of developers inthe future.

ACKNOWLEDGMENTS

We are most grateful for the assistance provided by a number of growers in allregions who allowed Divisional staff to conduct research and/or monitoring plantgrowth and related observations on their properties. This collaboration has enhancedthe effectiveness of research conducted and optimised our resource utilisation.

Assistance provided by the Rural Industry Research & Development Corporation forthree projects; Irrigation studies with Rambutan and Cupuacu, Responses ofAsparagus to droughting and Durian research is most appreciated.

Dr Niranjan R DasariDirector, Horticulture Division

7HORTICULTURE DIVISION STAFF

NAME DESIGNATION LOCATION (*)

DASARI Niranjan RB.Agr.Sc., M.Agr.Sc., Ph.D.Assoc. Dip. (Computing)

LIM, Tong KweeB.Agr,Sc.(Hons), M.Agr.Sc., Ph.D.

KULKARNI, VinodB.Agr.Sc., M.Agr.Sc., Ph.D.

BLACKBURN, KevinB.Agr.Sc.

POWELL, Jeremy 1B.Sc.

DICZBALIS, YanB.Agr.Sc., M.Agr.Sc.

LANDRIGAN, MargaretB.Sc.(Hons)

MARCSIK, Doris 2B.Agr.Sc.(Hons)

POFFLEY, MichaelDiploma Agr.

LUDERS, LanaB.App.Sc.

TRAYNOR, MarkCert.Trop.Hort.

HAMILTON, DavidTrade Cert.Hort.,B.Hort.Sc.(Hons)

WICKS, ChrisB.Sc. Agric.

NEILSEN, DebbieCert.Trop.Hort.

JETTNER, Colin

RAMSAY, GaryCert.Trop.Hort.

CLAPE, Warwick

MULLINS, Andy

SLINGER, Peter

Director of Horticulture

Principal Horticulturist

Senior HorticulturistPerennial Crops

Senior HorticulturistAnnual Crops

Senior HorticulturistOrnamental Crops

Senior HorticulturistIrrigation Research

HorticulturistPost Harvest

HorticulturistWinged Veterbrate Pests

HorticultureExtension Officer

Technical Officer (T3)Perennial Crops

Technical Officer (T3)Annual Crops

Technical Officer (T3)Perennial Crops

Technical Officer (T3)Irrigation

Technical Officer (T2)Ornamental Crops

Orchard Manager (T3)BARC Orchard

Orchard Manager (T4)CPRS Orchard

Technical Officer (T2)Research Station



BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

BARC

CPRS

CPRS

CPRS

CPRS

8HORTICULTURE DIVISION STAFF

NAME DESIGNATION LOCATION (*)

CARTER, Jane 3Adv.Cert.Trop.Hort.

ALBANO, PaulAdv.Cert.Trop.Hort.

McMAHON, Geraldine 4

HOPKINSON, Peter

SMITH, MalcolmB.Agr.Sc.

HOULT, MarkAss.Dip.Rural Tech. (Hort.)

FOORD, GavinCert.Ag.

BRIGHT, JeremyAssoc.Dip.App.Sci,B.Sc.(A.E.S)Grad. Cert. GIS

McALISTER, StuartAssoc.Dip.App.Sci

MARTIN, StevenDip.App.Sci.(Agriculture)

EASTBURN, Sandra 5

KENNA, GeoffDip.Hort.Sci.

MANSFIELD, John 6B.Agr.Sc., Ph.D.

YOUNG, KylieAssoc.Dip.Farm Man.(Hort)Assoc.Dip.Farm Man.(Apic)

FREEMAN, Shirley 7

ISGRO, NicAdv.Cert. AgricAdv.Cert.Hort

ELLIS, CarolynCert.Turf Management

MILLER, Scott

Technical Officer (T2)


Technical Officer (T2)RIRDC Project

Technical Officer (T1)Limited Tenure

Regional HorticulturistKatherine

Senior Technical Officer (P2)Perennial Crops

Senior Technical Officer (T4)Research Farm





Regional HorticulturistAlice Springs

Senior Horticulturist






BARC/CPRS

BARC/CPRS

BARC

CPRS

KRS

KRS

KRS

KRS

KRS

KRS

KRS

AZRI

AZRI

AZRI

AZRI

AZRI

AZRI

AZRI

1 Left March 1996 2 Left April 1996 3 Left March 1996 4 Left January 1996 5 Joined September 1995 6 Joined October 1995

7 Left February 1996

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LOCATION DETAILS

Berrimah Agricultural Research Centre (BARC)PO Box 990

DARWIN NT 0801Phone:(08) 89 995511Fax:(08) 89 992049

Coastal Plains Research Station (CPRS)Postal Address c/- BARC

Phone:(08) 89 888085Fax:(08) 89 888008

Katherine Research Station (KRS)PO Box 1346

KATHERINE NT 0851Phone:(08) 89 739739Fax:(08) 89 739777

Arid Zone Research Institute (AZRI)PO Box 8760

ALICE SPRINGS NT 0871Phone:(08) 89 518111Fax:(08) 89 518112

Ti Tree Research Farm (TTRF)Postal Address c/- AZRIPhone:(08) 89 569739Fax:(08) 89 569825

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MANGO RESEARCH IN CENTRAL AUSTRALIA

G Kenna, J Mansfield, K Young, N Isgro, A Mullins

The objective of this project is to evaluate the commercial production of mangoes inthe southern region of the Territory for the lucrative late season domestic market.

In 1990 two experimental plantings were made at the Ti Tree Research Farm. Thefirst plantings consist of 12 cultivars in a single row running north-south at a spacingof 3 m between trees. For nine of the cultivars there are two trees of each cultivarplanted adjacent to each other. For the other 3 cultivars (Davis Haden, Keitt andManzanillo Nunez) there is only one tree of each. All the trees are on Kensingtonrootstock except for the Manzanillo Nunez which is on Adelaide River Common. Thesecond experiment is a high-density planting trial where six plots are planted in aneast-west direction. Two plots are single row plantings of 5 trees each of Kent andNaomi at 2 m spacings between trees. Another four plots are double row plantings ata spacing of 2 m within rows and 2 m between rows. The two rows are offset to eachother by 1 m. One row contains five trees and the other contains four. The cultivarsgrown in these plots are Palmer, Keitt, Kent and Springfels. All the trees are onKensington rootstock.

For both experiments, mature fruit were harvested and weighed. The date and treefrom which it was removed was recorded. From this information it is possible tocompare the cultivars for differences in harvest patterns, fruit size, number of fruit pertree and yield (kg fruit/tree).

The results of the cultivar trail for the 1996 harvest season (Figure 1) showed thatIrwin was one of the first cultivars to produce mature fruit and had the longest harvestperiod although fruit size was small (302 g). Lippens produced fruit for a long periodand had the highest number of fruit however fruit size was the smallest (251 g). Keittand Kent had satisfactory fruit size, (454 g and 531 g average, respectively) howeverthe yield for Kent was very low (6 fruit). Keitt was one of the latest maturingvarieties. The cultivar R2E2 had the largest fruit (average 647 g), a yield/tree of 12 kgand was one of the earliest to mature (Figure 1).

In the high density trial, the 1996 harvest results (Figure 2) showed a differencebetween the Kent planted in the single row plot and those planted in the double rowplot. The single row planting had almost three times the yield per tree of the doublerow planting and also had larger fruit (average of 511 g compared to 433 g). Allcultivars in this trial except for the Kent in the single row plot had average yields pertree of less than 6 kg. The cultivar Springfels had an average fruit size of 668 g andthis was higher than the average fruit size of R2E2 in the other trial (647 g) thoughR2E2 produced the largest fruit for the 1996 season of 1292 g.

11a) Harvest range and duration

1-Jan

21-Jan

10-Feb

1-Mar

21-Mar

10-Apr

30-Apr

b) Yield/tree

0

5

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25

c) Fruit Number/tree

0102030405060708090

d) Average and range in fruit weight

0100200300400500600700800900

10001100120013001400

Cultiva rs

454393

515

302251

301

635

464541531

647

Figure 1. Comparison of mango cultivars at Ti Tree Research Farm

12a) Harvest range and duration

1-Jan

21-Jan

10-Feb

1-Mar

21-Mar

10-Apr

30-Apr

b) Yield/tree

0

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13

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100200

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Cultiva rs

379433

511

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668

Figure 2. Comparison of mango cultivars in the high density trial at Ti Tree ResearchFarm.

14

VARIATION IN MANGO PRODUCTIVITY

G Foord, J Bright, M Smith, M Hoult, S McAlister, L de Souza, M Landrigan

IntroductionIn 1995 some of the largest Kensington mango trees in the Katherine district producedless than a tray of marketable fruit. Other trees, of similar size, produced over 30trays. This highlights the variation between orchards and between trees within thesame orchard. DPIF Horticulture staff are attempting to identify why such variationsexist, compile a record of the size and productivity of the industry and develop amodel to predict productivity.

Materials and MethodsWe have identified groups of three trees in orchards on different soil types of variedbearing age and management practices. Data on phenology, nutrient status (atflowering and after harvest), fruit yield and fruit quality were collected from thesetrees in the 1995 season. Data collection will occur for at least the next two seasons,using the same trees.

Results and Discussion1995 data clearly show that some orchards are far more productive than others andthat this does not directly relate to orchard age, trunk circumference (see Figure 3.) orindeed, a number of other parameters. It will be necessary to accumulate at least thenext seasons' data before any real conclusions can be drawn. We expect to find that anumber of factors (nutrition, irrigation and soil type) in combination, must beconsidered in order to achieve optimum fruit yield and quality. The large variationsalready identified in this project clearly suggest that considerable opportunities existto boost productivity in the industry.

One interesting finding, was that the levels of leaf nitrogen content we detected atflowering and after harvest, did not significantly influence marketable yield or fruit size.However, the correlation between leaf zinc content and marketable yield was significant(Adj R-sq 0.468). This was strongly influenced by some extremely high zinc levels in asmall group of high yielding trees. Considering the size of the database we can reallyonly surmise from this that high zinc levels do not have a negative effect on yield.

Some useful information was gained in relation to future data collection. Manymeasurements were taken to determine tree size. These included the height and width ofthe tree canopy height and width and several measurements of trunk circumference (atdifferent heights above ground level and above and below the graft union). There was agood correlation between trunk circumference at 20 cm and 40 cm from ground level(see figure 4.) and between trunk circumference and canopy volume (see Figure 5.). Thiswill enable us to continue data collection using trunk circumference to indicate tree sizewithout the need to perform time consuming tree canopy measurements.

15

marketable trunk circumferenceweight 20cm from

ground(cm)

16.9 450 35.50 32

209.48 104196.8 99

173.22 11276.48 5781.64 57.599.74 65.5

109.34 114108.22 95

91.5 109

0

20

40

60

80

100

120

140

0 50 100 150 200 250

Marketable yield (kg)

trun

k ci

rcum

fere

nce

at 2

0cm

(cm

)

Figure 3. Correlation between trunk circumference and marketable yield (Adj R-sq -0.0506)

0

20

40

60

80

100

120

0 20 40 60 80 100 120 140

Trunk circumference at 20cm (cm)

Tru

nk c

ircu

mfe

renc

e at

40c

m (c

m)

Figure 4. Correlation between trunk circumference at 20 cm from ground level and trunk circumference at 40 cm from ground level (Adj R-sq 0.9586)

0

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Canopy volume (m)

Tru

nk c

ircu

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renc

e at

20c

m (c

m)

Figure 5. Correlation between trunk circumference at 20 cm from ground level and tree canopy volume (Adj R-sq 0.8208)

16

Through the use of remote sensing and GIS techniques we will identify mangoplantation numbers, sizes and changes over the last five years. This, with fieldsurveys, will determine the age of new orchards and identify when they will comeinto production.

We have compiled a survey form and are interviewing growers in the Katherineregion and collecting information on productivity and management practices (ie;irrigation, nutrition, pruning, chemical treatment, weed control, planting systems andyield).

MANGO POSTHARVEST RESEARCH

M Landrigan

DISCLAIMER: Naming of proprietary products in this review does not implyendorsement by DPIF. Postharvest chemical usage is currently controlled by strictgovernment legislation. It is illegal to use any chemical product for which specificregistration does not exist.

This season postharvest work continued in three areas;1) Consolidating the ripening work2) Sapburn and skin browning control3) Postharvest disease control

1) Mango ripening with EthrelOver the last few seasons we have shown that the application of an Ethrel dip canincrease the rate of mango ripening. Thanks to work carried out in the Horticulturesection, Graeme Patch and John Alcock from Resource Protection, as well as dataprovided by the chemical company Rhone Poulenc we have obtained Off-labelMinimal Use registration for next season only.

The rate to be used is 1mL/L Ethrel dip, with a withholding period of 4 days.Which simply means that fruit should not be ready to eat till at least 4 days aftertreatment, consequently only mature early season fruit should be treated.

2) Skin browning and Sap burn control

(i) Visit to southern markets

The main activity this season was a visit to the southern markets to monitor mangoharvesting and postharvest management systems in relation to mango fruit quality.This occurred in the last week of October which coincided with the middle of the NTseason. An exceptionally high incidence of mango anthracnose and skin browning wasobserved in Melbourne, Sydney and Brisbane. Twenty three assessments were made inthe wholesale markets and about thirty retail outlets were visited and fruit assessed.Around 50-60 % of the lines examined had browning problems that would affectsaleability. Table 1 illustrates the percentage of fruit out of grade with a specificdisorder.

17

Table 1. Disorders seen in the markets 26/10/95-2/11/95.

Disorder % Fruit AffectedAnthracnose 30Stem end rot 8Sapburn 13Blemishes 12Browning 25

On return to Darwin, follow up visits to packing sheds were carried out, along withdiscussions with growers to elucidate the causes of these significant problems.

As a result of a classification system developed by QPDI Hamilton researchers thebrowning can be differentiated into the categories shown in Table 2.

Table 2. Browning Classifications

Browning % Fruit AffectedEtching/smearing 29Abrasion 16Blotching 3Spotting 13Resin canal 32

The following causes of skin browning have been put forward:

-excessive water imbibition by fruits, from heavy irrigation, rain, leaving fruit too long indips, leaving wet fruit in contact with other fruit or hard surfaces-detergents, used at high concentrations-sap, in dirty dips and on equipment

There are, however still many unknowns and it is thought preharvest factors also have arole to play. More work will be continuing this season.

ii) Monitoring of sheds

Fruit were collected from four sheds, who use different postharvest systems on oneoccasion during the season. Fruit was assessed for browning and then stored at 10 °C for3 weeks, followed by 3 days at 22 °C and assessed again. At the end of the storage timebrowning was minimal on fruit from all four sheds. As fruit ripened browning becamemore apparent.

18

Table 3. Assessment of browning (score 1-5;1=nil, 5=severe) on fruit from four packingsheds in the Darwin area, after storage for 3 weeks at 10 °C and then when ripe.

Shed Browning after 3 weeks Ripe Fruit1 1.2 *a 1.9ab2 1.0a 2.8c3 1.7b 1.5a4 1.0a 2.4bc

* Means within columns followed by the same letter are not significantly different atP=0.05.

The type of browning seen here did not correlate with any specific management systemsin this small trial.

A comparison was also made between fruit harvested mechanically and fruit handharvested, from the same orchard. Browning problems were minimal. This furtheremphases the importance of pre-harvest factors in determining skin browning problems.

iii) Mango Wash and skin browning

Effect of postharvest treatments on skin browning. Last season postharvest treatmentsincreased the incidence of skin browning. Fruit were desapped into Mango Wash ateither 5 g/L or 20 g/L, this was followed by a one minute spray with Sportak (0.55ml/L) and finished with a light brushing. The incidence of skin browning increased witheach additional postharvest treatment and was slightly higher for fruit treated at thehigher rate of Mango Wash, although this effect was not significant. However, careshould be taken with amounts of detergents used and under some conditions (eg heavyrains last season) skin browning is inevitable.

iv) Paraffinic oils and skin browning

Two new oils were trialed for alleviating sapburn and their affect on skin browning.These were 1) DCTron +, a new horticultural petroleum spray oil, boosted for efficacyand lower chance of phototoxicology and 2) a light medicinal oil, with medicinalsurfactants, currently being trialed in the citrus industry. Sap burn was only slight for allthe treatments. Skin browning did not seem to be aggravated by the use of these oils.However the risk of heat injury was increased when these oils were used prior to heattreatment for fruit fly disinfestation.

19

0

1

2

3

4

5

Wat

er

DC

Tron

DC

Tron

+

Med

. oil

Treatment

Scor

e (1

-5)

Skinbrow ning

Heatscald

Figure 6. Effect of paraffinic oils on skin browning and heatscald damage.

3) Postharvest disease controlThis year, I think demonstrated how unseasonal rain in drier growing regions andshowery weather can accelerate the development of anthracnose. Infection takes place inthe orchard, then the anthracnose places a waiting game and lies dormant until the rightconditions are triggered by the ripening process. Use of the postharvest dip prochloraz asan overhead NON-RECIRCULATING spray will help control the fungus. And finallytemperature is a key factor in anthracnose development. With this in mind when welook at these results from last season.

Fruit from two growers in the NT were collected and half the fruit were treated withprochloraz, the remainder were left untreated. The fruit were then stored at the followingtemperatures, 10, 15, 22 and 30°C and scored for incidence and severity of anthracnosewhen fruit were ripe.

Firstly, one of the growers had a slightly higher overall incidence of anthracnose,highlighting the importance of preharvest controls. Secondly, to a certain extent theincidence of anthracnose is not dependent on the storage temperature. However, theseverity of disease increased with an increase in temperature. Finally, the coldprochloraz treatment was successful in reducing postharvest disease.

20

0

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10 15 22 32

Temperature (C)

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hrac

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sco

re (1

-5)

0

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Frui

t Firm

ness

Inde

x (F

FI) Control

Sportak

FFI

Figure 7. Effect Sportak treatment and storage temperature on anthracnosedevelopment (score 1-5; 1=nil, 5=severe) after 10 days storage. Klsd (P=0.05) for themeans anthracnose scores=0.55.

DAILY TEMPERATURES TO PREDICT HARVEST DATE OF MANGOES

Y Diczbalis, C Wicks

IntroductionMango fruit maturity is a topic of interest to most growers early in the season.Methods to determine maturity for the most part are based on the “dry matter test”and “flesh colour” and dare I say for some producers “PRICE”. Large quantities ofimmature fruit on the market decreases the price and hence producers of high qualitymature fruit are adversely affected. The image of the NT mango industry also suffers.

The maturity guides used (dry matter and flesh colour) to guide growers in theselection of mature fruit are not totally reliable. Evidence gathered through researchand experience indicate that fruit “dry matter” and “flesh colour” are influenced byconditions other than fruit maturity such as, irrigation management, soil type, growinglocation and season. For example research has shown that dry matter of the sameaged fruit can be as much as 2.0% higher in fruit from trees given the least amount ofwater compared to the highest irrigation rates. The fruit from the low irrigationtreatments harvested at 14% DM did not achieve the same quality at ripening as thefruit harvested from the high irrigation treatment at 14% approximately two weekslater. Time spent on the tree determines fruit maturity not indicators such as drymatter and flesh colour.

MethodA method used to determine the length of growth stages in other crops, based on timeand temperature during the growing period, known as heatsums (thermal-time) maybe a useful and more reliable guide for determining fruit maturity in mango. Themethod is based on multiplying the calendar days for a particular growth period with

21

the average temperature during that time. Hence the units for the outcome areexpressed as growing degree days (GDD). In our calculations to date we have usedeither weekly or daily maximum and minimum temperature, depending on availabilityand the days from early flowering to harvest. As part of our temperature calculationswe have used a base growing temperature of 12oC, temperatures below this are notused in the thermal time calculation as they are thought to be to low for growth inmango

ResultsResults gained from our irrigation monitoring work carried out over four years (1992- 1995) and from work carried out at Ti-Tree in 1988/89 are shown in Table 4.

Table 4. Thermal Time for mango maturity in the NT for different locations and years

Year Location Temperature DetailThermal Time (GDD)

from flowering to harvest.1988/89

(M. Hoult)Ti-Tree Monthly max and

min1,445

1992 Berry Springs Weekly max andmin

1,738


1,535


1,624

1995 Acacia Hills Daily max and min 1,530MEAN 1,574

(Max = maximum, min = minimum)

DiscussionThe data suggests that there is a close relationship between thermal time and fruitmaturity over a range of seasons and environments. In the above examples there wasno attempt to compare thermal time determined maturity with other fruit maturitypredictors or fruit quality at ripening.

If thermal time can be shown to be a more reliable indicator of fruit maturity, thereare a number of possible benefits to industry. Firstly the method could be used torecommend the optimal time, for each growing region, to commence selectiveharvesting. For example, temperatures could be monitored for growing regions andan advisory note published weekly in the newspaper (See example Table 5). Thisinformation could also be used by packing sheds to recommend to their clients whenselective harvesting should commence.

22

Table 5. Thermal Time (GDD) for the following growing regions as of October 15 forflowering times 17 June to 22 July. A thermal time of 1600 GDD is recommendedprior to the commencement of selective harvesting. Contact DPIF extension officer(ph 99200) or your packing shed manager for more details.

Today’s date 15 October Selective picking can commence at 1600 GDDThermal Time (GDD) from flowering for the regions below

FloweringDate

Middle Pt. Lambells L. Humpty Doo Berry Springs

17 June 1633 1600 1655 158024 July 1577 1573 1590 15001 July 1490 1489 1500 14408 July 1402 1400 1450 139015 July 1316 1300 1330 128922 July 1219 1210 1270 1199

Secondly, the method could be used as a farm management tool for individual farms.Once flowering commences the farm manager/owner, with the aid of averagemaximum and minimum temperature data and a calculator or computer will be able touse the method in a predictive manner to indicate when harvesting may commence.As each days maximum and minimum temperature is recorded and superimposed onthe average temperature data the predicted harvest date can be updated. Thisinformation would allow the farm manager to better organise labour requirements,fruit availability information and transportation requirements.

Work to be carried out this coming season will attempt to determine if there is arelationship between fruit maturity and possible maturity indicators such as; thermaltime, flesh dry matter, flesh colour, fruit appearance at harvest, ripe fruitcharacteristics such as days to soft ripe and post harvest fruit quality characteristics.Ideally this work should be carried out over a large a range of growing sites andmanagement practices as possible. This season the work will be carried out at onesite.

EFFECT OF PRE-FLOWERING SOIL MOISTURE AND CULTAR ONFLOWERING, FRUIT SET AND YIELD OF KENSINGTON PRIDEMANGOES.


23

IntroductionIrrigation monitoring studies carried out in past years suggested that mango waterrequirements were low in the few weeks following the commencement of irrigation atflowering. This low period of water use coincided with fruit set. Following fruit setwater requirements increased. It was suggested that the relatively low water use at thetime of fruit set may have been due to the lack of operational feeder roots followingthe extended pre-flowering drought and that this may be adversely affecting fruit set.A three year trial was initiated in 1995 at Acacia Hills Farm to determine whether pre-flowering irrigation influenced fruit set. The trial investigated the effects of soilmoisture and temperature and the flowering promoter Cultar.

MethodCultar treatments were imposed on 4.5 year old trees in late December 1994following pruning. Untreated trees (Non Cultar) were pruned at the same time. Anirrigation system was installed which allowed four pre-flowering irrigation treatments(50, 25, 13 and 0 mm/week) to be imposed from the end of the wet season (late April)until flowering. Following flowering trees were fully irrigated (approximately 40mm/wk) through to harvest. Measurements undertaken at the site included, soiltension, total soil moisture (EnviroScan), daily maximum and minimum temperature,tree phenology (flushing, flowering etc), flowering panicle number per tree andharvest measurements such as fruit number and total tree yield. The data presented aremeans of six trees per treatment.

ResultsMonitoring of vegetative flushes indicated that both Cultar and Non Cultar treatedtrees had a similar number of flushes following the onset of the dry season. Irrigationtreatments did not influence the flushing activity of the tree. There were four to sixflushes, depending on the tree aspect, between pruning and first flowering. The firstflowering occurred in Cultar treated trees and flowering was approximately a weeklater in Non Cultar treated trees (Table 6).

Table 6. Effect of flowering promoter and pre-flowering irrigation on the time offlowering (50 % of tree). (Standard Error (SE) for comparison of treatments = 1)Irrigation Treatment Cultar Non Cultar50 mm/wk 21 July 7 August25 mm/wk 18 July 24 July13 mm/wk 19 July 27 July0 mm/wk 20 July 24 July

The number of flowering panicles was significantly higher in Cultar treated trees.Irrigation treatments decreased flowering in Non Cultar treated trees and increasedflowering in Cultar treated trees (Table 7).

Table 7. Effect of flowering promoter and pre-flowering irrigation on the number offlowering panicles per tree.(SE for comparison of treatments = 28)

Irrigation Treatment Cultar Non Cultar50 mm/wk 252 4825 mm/wk 245 134

24

13 mm/wk 186 1420 mm/wk 148 152

Similar trends occurred for final fruit number per tree and fruit set (Table 8).

Table 8. Effect of flowering promoter and pre-flowering irrigation on fruit number pertree (SE = 11) and fruit set % in brackets (SE = 4.4).Irrigation Treatment Cultar Non Cultar50 mm/wk 47 (23) 13 (28)25 mm/wk 78 (31) 58 (44)13 mm/wk 44 (22) 59 (40)0 mm/wk 44 (29) 76 (52)

Tree yield was reduced by irrigation in the Non Cultar treatments and peaked at airrigation level of 25 mm/wk in the Cultar treated trees. The maximum yields forCultar and Non Cultar treated trees were the same (Table 9).

Table 9. Effect of flowering promoter and pre-flowering irrigation on tree yield (SE =5).Irrigation Treatment Cultar Non Cultar50 mm/wk 23 725 mm/wk 38 2913 mm/wk 22 280 mm/wk 21 37

DiscussionThe data revealed that under the temperature conditions which prevailed, floweringwas enhanced by one week through the use of Cultar. Irrigation pre-floweringadversely affected flowering in the Non Cultar treated trees but enhanced floweringin the Cultar treated trees. The earlier flowering (1 week) in Cultar treated treesdid not result in earlier fruit maturity. Cultar increased the number of floweringpanicles per tree but there was no evidence of a similar increase in yield as fruit setwas reduced in Cultar treated trees. There was no evidence to suggest that dryconditions pre-flowering reduced fruit set for either Cultar and Non Cultar treatedtrees in fact the reverse may be said to have occurred. This suggest that tree yieldmay be limited by tree physiological factors and hence the tree can only support acertain number of fruit regardless of the number of flowers produced.

The data and comments above are based on the first seasons data and should beinterpreted with caution. The trial is planned to continue for the next two seasons.Our thanks to Acacia Hills Farm for their continued support.

INDUSTRY DEVELOPMENT AND SUPPORT

K Blackburn and M Traynor

25

The formation of a Banana Working Group by DPIF, which includes both Darwin andKatherine Banana Growers, was a major recommendation of the first BananaWorkshop held in August 1993. This group meets three times a year and includesmeetings on growers farms, to discuss and suggest R & D projects for the industryand any other relevant industry matters with DPIF and other NT Governmentrepresentatives.

One of the first recommendations of the Working Group was the quarantine limitationon the importation of banana planting material into the NT, other than by tissueculture plants, to prevent the introduction of bunchy top and Panama disease. Overthe past two years DPIF has worked in closely with the industry and many significantachievements have been made. Some of these include:

• Grower study tours to North Queensland and Kununurra,• Grower and DPIF representatives attended the first National Banana Industry

Congress in May 1995.• An NT industry awareness of national banana issues eg quarantine pests such as

the oriental fruit fly and the spiralling white fly.• NT inclusion in the Black Sigatoka Disease Exclusion Project• Fact Files containing relevant extension and research articles on bananas culture

have been distributed to all growers. These are updated at intervals.• The Banana Working Group has been involved in general policy in the banana land

release strategy at Lambells Lagoon.

The Banana Working Group has been able to co-ordinate advisory services to growersand assist in the development of industry initiatives. The Research and Developmentprogram over the past two years has covered the following areas:

• Crop water requirements research• Nutrient monitoring project (1994 - 1997)• Pest and disease monitoring and control

− Nematode survey report (1994)− Pest and disease survey report (1994)− Integrated pest management project (1995 - 96)

• Banana cultivar assessment (Darwin & Katherine)• Sucker selection and nurse sucker technique evaluation (Katherine)• Plant Quarantine review to protect the NT Industry

Future developments are planned in

• In-store quality monitoring of NT fruit with grower feedback.• Benchmarking project• Local NT banana promotions• Quality management programs• Continuation of Integrated Pest Management work• Potential for pesticide-free production

26

The Banana Working Group provides an excellent forum for interaction betweenproducers and DPIF. The NT banana growers have run a local promotion projectusing their own funds with Australian Banana Growers Council television and instorepromotional material.

The NT industry is set to expand significantly as new farms come into production.The NT Government is addressing problems of land availability with adequate water,power and areas close to population centres.

The top end of the NT is highly attractive for banana production having a warmgrowing environment, a long dry season, adequate back loading with freight, relativefreedom from pests and diseases and a lower incidence of cyclones than northQueensland.

BANANA NUTRIENT MONITORING

K Blackburn, M Traynor

A banana nutrition monitoring program, consisting of bi-monthly leaf and soilanalyses commenced in March 1994. These are to be correlated with grower fertiliserpractises, over a three year period, to optimise banana nutrition.

Initially the project set out to identify what the situation was in regard to nutritionalstatus of the plants and the frequency, amounts and type of fertiliser presently beingapplied. Results in the first year (1994) over 5 sampling dates showed that regularmonthly fertiliser application was not always occurring especially during the wetseason when access to the crop is restricted by water-logged conditions. The rates ofapplication used by the 5 growers vary from 100 kg/ha/month with an average ofabout 200 kg/ha/month which corresponds to an annual rate of 330 kg N, 72 kg P and720 kg K per ha.

During 1995, farm fertiliser applications became more regular with an averageincrease in the total amount of fertiliser used. However, growers could not provideany yield estimates to determine whether the improved nutrition, has in fact, increasedfarm productivity. Although all growers agreed that production had improved. As in1994, high soil magnesium levels has affected both potassium and calcium leaf levelsby altering the cation balance and restricting their uptake by the plant. Low soilpotassium levels on most farms could be improved by small regular applications ofpotassium with 2 or 3 major applications at seasonal intervals. The maintenance ofadequate zinc levels in the leaf is an industry-wide problem. High soil zinc levels onone farm has not resulted in adequate leaf zinc levels although foliar application ofzinc is also used.

27

After two years of farm monitoring the results could be briefly summarised:

• Regular monthly applications of nutrients should be strictly carried out to maintaina constant supply to the growing crop. It is anticipated that, as the phenology ofthe crop is better understood, critical times for additional fertiliser applications willbe determined. For example. additional potassium could be required inMarch/April before the onset of cool dry season conditions.

• The importance of precise irrigation scheduling in bananas under local conditions

cannot be over-emphasised. Unless this is achieved, the response from animproved nutrition program will not be obtained. Current irrigation scheduling isgenerally variable and water is insufficient during Sept./Oct./Nov. when climaticconditions are harsh and banana crops are under undue stress. New plantings onexisting farms as well as two very large banana ventures just commencingoperations are using undertree sprinkler irrigation systems, rather than thetraditional overhead method, and will be injecting fertiliser through the irrigationsystem at regular intervals. It is considered that this system will be more efficientin supplying the irrigation requirements and the nutrient demands of the bananacrop under Darwin climatic conditions.

• Strategies for improving both zinc and potassium nutrition to ensure constant and

adequate levels in the soil and plant will have to be developed. The highmagnesium content in the irrigation water from bores is a concern and the effect onpotassium availability may only by partially overcome by small, frequentapplications of potassium fertilisers. Maintaining adequate zinc levels in the soiland leaf is an industry-wide problem and both ground and foliar application willneed to be employed to overcome deficiencies.

• The use of nutrient ratio’s such as the DRIS system, may offer more in analysing

nutrient interaction over time in a banana crop, rather than attempting to definestraight nutrient levels. There is a real need to develop the diagnostic technologynecessary to improve crop productivity but grower feedback is essential for this tohappen. Plant reserves and the cycling of some nutrients, such as potassium, needto be understood far more than the current knowledge available for strategicapplication of fertiliser.

• On one farm during 1995, leaf petiole sap analyses was carried out on foursampling dates, to compare the results against standard dry matter analysis. Therewas a good relationship for phosphorous and zinc, but not for nitrogen, potassiumand magnesium.

There was no correlation with the calcium levels of both analyses. Although thissmall project was only a preliminary look at the petiole sap analysis techniquethere are good indications that it could be used for some elements for grower use asan aid in decision making. Further evaluation of the method would require a muchlonger number of samples to be taken over a season.

28

• Figures 8 and 9 show both leaf and soil levels for a number of nutrients over 6farm sites and 6 sampling dates during 1995. The two horizontal bars represent therange of adequate levels of nutrients for leaf analysis, while the single horizontalbar in the soil analysis is considered to be an optimum level. Generally, nitrogenleaf levels could be higher on all farms earlier in the year but access problemsduring the wet season means that the necessary fertiliser is not always applied.Nitrogen levels are adequate in September after the cool, dry season, when plantsare growing actively.

29

LEAF ANALYSIS - NITROGEN

1

2

3

4

FARM1

FARM2

FARM3

FARM4

FARM5

FARM6

LEA

F (%

N)

2/02/95

30/03/95

31/05/95

1/08/95

28/09/95

5/12/95

3.5% N

3.0% N

LEAF ANALYSIS - POTASSIUM

1

2

3

4

5

FARM 1 FARM 2 FARM 3 FARM 4 FARM 5 FARM 6

LEA

F (%

K)

2/02/95

30/03/95

31/05/95

1/08/95

28/09/95

5/12/95

4.0% K

3.33% K

SOIL ANALYSIS - POTASSIUM

0

50

100

150

200

250

300


SOIL

(ppm

K)

2/02/95

30/03/95

31/05/95

1/08/95

28/09/95

5/12/95

150ppm K

Figure 8. Leaf and Soil Levels

30

LEAF ANALYSIS - CALCIUM

0

0.5

1

1.5


LEA

F (%

Ca)

2/02/95

30/03/95

31/05/95

1/08/95

28/09/95

5/12/95

0.9% Ca

0.6% Ca

LEAF ANALYSIS - ZINC

0

5

10

15

20

25

30

35

40

45


LEA

F (p

pmZn

)

2/02/95

30/03/95

31/05/95

1/08/95

28/09/95

5/12/95

35ppm Zn

21ppm Zn

SOIL ANALYSIS - ZINC

0123456789


SOIL

(ppm

Zn)

2/02/95

30/03/95

31/05/95

1/08/95

28/09/95

5/12/95

2ppm Zn

Figure 9. Leaf and Soil Levels Potassium leaf levels are generally adequate early in the year before the onset of the

cool weather but then drop off. Soil levels are variable but are good on 2 farms

31

that have a regular fertiliser program. Zinc leaf and soil levels are variable,generally inadequate and are a major nutritional problem. This project willcontinue for another 1 to 2 years and it is hoped that some strategies for improvinganana nutrition will be developed in that time.

BANANA CULTIVAR ASSESSMENT


One of the recommendations of the 1993 Banana Workshop was that a collection ofrelevant banana cultivars be established at the Coastal Plains Research Station forassessment of these under local conditions. The Banana Industry Working Group,with advice and co-operation from QDPI, decided that the collection should containcultivars that are popular with the major ethnic groups that have settled in the NT. Itwas considered that there would be less inclination to illegally bring in these cultivarsif they were locally available and so reduce the threat of disease importation fromcountries in the South East Asian area. As well, some new introductions and QDPIselections were included for assessment. Among these was Goldfinger, a newbreeding line from Honduras which has some excellent agronomic characteristics.

The original introductions arrived in early 1994 as “in vitro” tissue culture plantletsbut due to the varying number of plants recovered after growing on, these wereplanted in a temporary museum block. These were field planted on June 27, 1994into an undertree irrigation system. Two cultivars, Goldfinger and Santa CatarinaPrata were delayed due to legal and licence requirements and were field planted onDecember 13, 1994. In 1995, a larger banana arboretum block was planted out withincreased number of plants of each cultivar for assessment. Eventually suckers fromthese will be distributed to interested parties. The cultivar collection is listed in Table10.

Table 10. Banana cultivar collection at CPRSLab. Code Q Ban Reg. No. Cultivar

299299117229248259324362383401404411412321360

M450C398C405M421M438M320M259M511C543C550C582M559M566M567M508C541

SucrierJ.D. SpecialJ.D. DwarfLakatanPisang RajahPisang Gajih MerahDucassePacific PlantainDwarf French PlantainWilliamsGrande NaineSugarHorn PlantainImproved Lady FingerSanta Catarina PrataGoldfinger

32

EFFECT OF IRRIGATION RATE ON BANANA GROWTH AND YIELD.

Y Diczbalis, C Wicks, M Traynor, K Blackburn

The banana industry has grown rapidly over the last few years. Growers appreciatethe benefits of the Top End climate for the production of bananas with the mainproduction period occurring during our dry season when production in the other statesis limited. The late dry season, particularly the build up period when rain is isolatedand temperatures (day and night) are high, is a harsh growing period when watermanagement is critical if successful production is to occur. The water requirements ofbananas are well known as it is a well researched crop in Australia and overseas,however, there was a requirement to transfer the theoretical information to localexperience to develop a practical irrigation guide for growers.

Materials and MethodsA commercial patch of bananas at Middle Point was made available to us by acommercial grower. From early sucker emergence, four irrigation regimes (8.7, 6.8.5.1 and 3.8 mm/day) were imposed on the fourth ratoon crop. The irrigation systemconsisted of grey Waterbirds placed at 7 by 5 metre spacings. The aim of the trialwas to measure the effect of different irrigation rates on; leaf production rate, time toflowering, duration of fruit development stage, bunch weight and yield attributes suchas number and weight of hands. Ten plants were selected in each treatment forobservation of growth and phenological stages. At the 7-8 leaf stage (April 1995) thechosen suckers were tagged and leaf production was monitored fortnightly untilbelling. Following fruit set , the lowest one and a half hands were removed as pergrower practice and the bell removed and the bunch bagged. The bunches wereharvested when fruit had lost its angular appearance. Weekly maximum andminimum temperatures and rainfall and irrigation inputs were recorded. Soil moisturewas also monitored by tensiometer and capacitance probe.

Trashing, de-suckering, leaf spot and weed control were carried out by the growerwhile fertiliser inputs were controlled by DPIF. Fertiliser (NPK) was added daily viathe irrigation system initially at a rate 156, 65 and 312 kg/ha/year respectively. Thiswas increased to 390, 163 and 780 kg/ha/year later in the trial when it becameapparent, through leaf analysis, that the inputs were insufficient to meet therequirements of the crop. In general the leaf analysis data indicated that the crop wasunder fertilised and this needs to be taken into account when interpreting the results.

Results and DiscussionLeaf productionLeaf production rate was initially high (2 leaves/fortnight) but fell to approximately0.5 leave per fortnight by mid July. As night temperatures increased the leafproduction rate returned to approximately 1.5 leaves /fortnight just prior to belling. Itappears that the leaf production rate was independent of irrigation regimes. Thetemperature data indicated that the maximum temperatures remain constant (32-38oC)throughout the year but the minimum temperatures drop from 22oC in April to 8-10oCduring June and July with a return to 22oC from about mid August. It would appearthat the night temperatures are the major controlling factor of leaf production.

33

Plant size at belling and duration of growth stagesPlant size at belling was largest for the 6.8 mm/day irrigation treatment and smallestfor the lowest irrigation treatment (3.8 mm/day) Table 11.

Table 11. Plant height, stem circumference at 30 cm and green leaf number at belling

Irrigation(mm/day)

Plant Height(cm)

StemCircumference(cm)

Green leaf number

8.7 255 68.5 11.36.8 278 77.9 11.75.1 256 69.5 10.73.8 235 62.0 10.2

The duration of the growth phases was generally the least for the highest irrigationtreatment, however the period from tagging to belling was least for plants irrigated theleast (Table 12).

Table 12. Duration of growth stages

Irrigation(mm/day)

Days to bellingfrom 22 April

Days to harvest Total Duration

8.7 170 87 2576.8 195 90 2855.1 203 88 2913.8 169 95 264

Bunch weight, hand and finger number and hand size distributionYield and yield components were all highest for the 6.8 mm/day treatment (Table 13)with little difference occurring between the 8.7 and 5.1 mm/day treatments..

Table 13. Bunch weight, hand and finger number

Irrigation(mm/day)

Bunch weight(kg)

Hands per bunch Finger Number onthird hand

8.7 20.1 6.7 15.36.8 26.1 7.8 17.95.1 18.9 6.6 14.93.8 16.4 6.3 14.9

The majority of the fruit produced were in the extra large and large categories whichare the preferred market size ranges. Only the lowest irrigation treatment producedmore large fruit than extra large fruit (Table 14).

34

Table 14. Hand size distribution

Irrigation(mm/day)

Number of extralarge hands

Number of largehands

Number of mediumhands

8.7 3.6 2.9 0.26.8 4.1 3.5 0.25.1 3.7 3.3 0.33.8 2.8 3.4 0.1

Soil MoistureSoil moisture measurements indicated that for the 8.7 mm/day treatment, tensions at20, 40 and 80 cm were generally below 20 kPa for most of the year which indicatesthat the crop was kept at field capacity or saturated for much of the recording period.Tensions increased as the irrigation inputs decreased, with the highest tensionsrecorded in the 3.8 mm/day treatment, particularly during the build up period, whentensions reached 60, 80 and 70 kPa at 20, 40 and 80 cm respectively. Tensions in the6.8 mm/day treatment varied between 10 and 20 kPa for the 40 and 80 cm depthsdepending on time of the year and was much more variable at 20 cm with peakreadings of up to 50 kPa occurring early in the year and during the build up period.

DiscussionNone of the treatments were ideal for growing conditions through out the year. Thehighest rates caused water logging during the cooler months and the lowest rates wereinsufficient during the build up. Irrigation inputs should be scheduled usingevaporation based models or direct soil measurement such as tensiometers. The soiltension data suggests that irrigation as low as 3.8 mm/day are sufficient during thecoldest months of the dry season while the highest rate of 8.7 mm/day is moreappropriate for the dry build-up period (late August to October). During theremaining part of the season 5 to 7 mm/day would be appropriate.

Nutrient inputs were initially low and hence the plants were never at the optimumnutrient level. As a consequence yields were lower than expected. This experienceagain reinforces the co-dependence of nutrition and irrigation in achieving themaximum yield.

DURIAN CULTIVAR IDENTIFICATION, FLOWERING ANDPOLLINATION STUDIES

T K Lim, L Luders

The misidentification and erroneous labelling of cultivars can have a serious impacton the durian industry, extending across the whole spectrum from research toproduction to marketing. Imagine the frustration and tremendous waste on the time,

35

money and effort spent on research and development as well as the cultivation ofwrong clones with low market acceptance. Presently many of the introduced cultivarshave different characteristics to their namesake in their sources of origin. The use ofreproductive characters for confirmation of clonal density can only be done onmature, bearing trees before identification can be confirmed. In this paper we reporton the use of polygonal graph analyses of leaf characters from mature or seedlingdurian trees to differentiate between clones. A total of 50 leaf samples encompassing18 different clones collected from the Zappala orchard and QDPI South JohnstoneResearch Station in North Queensland and several localities around Darwin in theNorthern Territory were analysed. After preliminary investigations, eight reliable andsegregating leaf characters were chosen for the axes in the polygonal profilesdeveloped for each cultivar ( Fig 1). Using this method, a number of mistakes weredetected, for example, the so called “Monthong” brought in from Pomoho, Hawaii isre-identified as Gob Yaow while the tree labelled as Luang in the BARC orchard isGaan Yaow.

Durian flowering is initiated with the appearance of “pimple” protuberances on thebranches which occur in late June and July. Most rapid discernible growth occurswhen the protuberance starts to enlarge, develop, and differentiate into theinflorescence eg. from mid July through August. The most rapid floral bud growthoccurs just 1-2 weeks before bud burst. Usually it takes from 8-10 weeks fromprotuberance to flower anthesis and around 120 days (range 100-134 days) fromanthesis to fruit harvest. Our studies over the years showed that successful pollinationof durian flowers is determined by the prevailing weather conditions which stronglyinfluenced the activity of pollinators, flower opening and the viability andgermination of the pollens. The viability of durian pollens can be easily determinedby the use of Alexander stain. Germination of durian pollens can be determined usingsucrose plus boron agar medium. It was found that they germinated best attemperatures of 30°C and an alternating temperature of 20-30°C followed by 25°C,alternating 15-30°C and 35°C in descending order. Pollens from seedling treesgerminated more readily than the Thai cultivars although viability may be similar.

Assisted pollination studies revealed that most of the cultivars in Darwin requirecross-pollination for good fruit set and uniform, high quality fruit. Fruits formed byself-pollination are characterised by the following undesirable traits:

• fruit shape distorted and misshaped• lower fruit weight (33-50% lower)• spines in the deformed portion are longer and more dense• lower flesh recovery percent, 20% compared to normal 53%• rind of uneven thickness, thicker in deformed portion• increase in rind weight• usually 1 (infrequently 2) well-formed lobes instead of 5• low number of well-formed arils• lower fruit quality• shrunken and deformed seed• lower seed number and total seed weight• increase fruit wastage and lower profit resulting from unsaleability.

36

RAMBUTAN MULCHING TRIAL


Rambutans have been shown to be shallow rooted with greater then 85 % of the rootsystem present in the top 15 cm. Current irrigation practise is to irrigate daily so as tomaintain adequate soil moisture in the root zone. Daily irrigation although useful formaintaining soil moisture is inefficient as a large percentage of the water applied islost directly through evaporation from the soil surface.

The use of undertree mulch has been shown to improve soil moisture relations in thesurface soil horizons of many crops. In commercial rambutan orchards young treesare often mulched to aid tree establishment through the suppression of weeds andimproved soil moisture. However, established trees are rarely mulched due to theperceived limited benefits from such an activity. Established trees often have areasonable layer of natural leaf mulch which results from normal leaf fall, althoughthis is not always the case.

The aim of this work is to determine the effect of various mulches on soil water statusin rambutans irrigated at a high and low rate.

Materials and Methods

TreatmentsFour Mulching treatments

- No Mulch (Bare ground)- Natural Mulch (Leaves)- Hay Mulch (4 bales per tree)- Matting Mulch (Jute Matting to drip line)

Two Irrigation treatments- normal (125-175 L/day)- low (75-125 L/day)

The trial was conducted at CPRS in the netted rambutan variety block. There weretwo trees per treatment giving a total of 16 trees. Unfortunately it was not possible toselect only one or two varieties, so the treatments were assigned randomly to similarsize trees.

MeasurementsOnce per week the phenology (growth phase) of each tree was recorded as were thereadings from a bank of three tensiometers installed near each tree. At harvest fruitweight and total yield was measured.

Results and Discussion

37

Soil Water Content

Figure 10 attached shows the soil tensions at 20 cm for the hay mulch treatment withboth irrigation treatments. Only this graph has been attached as only the hay mulch atnormal irrigation levels kept the soil tension (at 20 cm) below the recommended levelof 350 mbar. The other treatments were not successful at retaining this low level oftension.

Tensions at 20cm for hay mulch at both irrigations

0

200

400

600

800

1000

9/05

/95

23/0

5/95

5/06

/95

20/0

6/95

3/07

/95

17/0

7/95

31/0

7/95

14/0

8/95

4/09

/95

18/0

9/95

3/10

/95

16/1

0/95

30/1

0/95

13/1

1/95

27/1

1/95

18/1

2/95

Date

Ten

sion

(mba

r) Low IrriNormal Irri

Figure 10. Tensions for hay mulch at both irrigations

Fruit Yield

The means for fruit yield (Table 15) appear to indicate a clear difference between thetreatments. However when the standard deviations ( a measure of variability) aretaken into account it is quite clear that there are no significant differences between thetreatments. It appears that the large differences (in yield) between varieties has over-ridden any differences brought about by the treatments.

Table 15. Fruit Yield from mulching and irrigation treatmentTreatment Yield (kg)

Irrigation Mulch Mean Stnd DevnLow None 29.95 15.13Low Leaf 80.125 71.17Low Hay 9.55 11.74Low Matting 37.15 51.12

Normal None 25.675 8.379Normal Leaf 31.175 29.73

38

Normal Hay 23.725 26.41Normal Matting 9.075 11.07

ConclusionThe results of this trial suggest that using hay mulch provides the best soil waterstatus for the growth of rambutans. However this data cannot be confirmed with yielddata as there was a high variability caused by the large number of varieties used. It isvery possible that the use of hay mulch may not provide any economic benefitscompared to natural leaf mulch. This trial would have to be conducted on a largerscale with only one or two varieties before any definite recommendations could bemade.

RAMBUTAN PRUNING TRIAL


There is little known about the activity of rambutans after pruning. In fact there islittle known about pruning of rambutans at all.

The current practice is to skirt the trees after harvest as well as to remove any watershoots (fleshy, succulent shoots arising directly from the main trunk) and internalshoots. Most growers remove the terminals during harvest or soon there-after. Therehas been little work done on shaping the trees which may be due to the markedvarietal differences in growth.

The aim of this trial is to examine the relationship between time of pruning andflowering, with particular emphasis on the amount of growth during that period. Thisproject is part of a RIRDC funded project being conducted by CSIRO (Brisbane) andQDPI (Maroochy).

Materials and Methods

TreatmentsA) Three pruning treatmentsNull Prune - - Minimal tip pruning at harvest (December)February Prune -2-3 whorls [30cm] behind tipApril Prune - 2-3 whorls [30cm] behind tip

B) Two varieties - Jitlee and R167

Measurements

There were three trees per variety per pruning treatment (18 trees in total) with 8terminals tagged and measured (once a week) per tree. The measurements were flushstatus and length, leaf number, flowering date and harvest data.

39

Results and Discussion

A)

Table 16. Number and Average Length of FlushesTreatment R167 Jitlee Overall

Number Length Number Length Number LengthNull Prune 2.92 143.1 2.46 139.0 2.69 141.1Feb Prune 4.00 153.2 2.92 84.0 3.46 118.6April Prune 4.54 124.2 3.13 84.8 3.83 104.5

There was a difference between the number of flushes for the pruning treatments(Table 16). There is also a clear difference between the varieties. This difference canbe explained by the flowering activity of the terminals.

B) Number of Flowering Panicles and Date of Flowering

As can be seen from Figure 11, there is a clear difference between the “Null Prune”treatment and the pruned treatments. There is a slight difference between the twovarieties but there was no real interaction between the two treatments. This differencein flowering behaviour is translated into yield with only the null-prune terminalsproducing fruit.

Conclusion

This data is only some of the results of the first year of the trial and as such should notbe used as any definitive answer to our questions on rambutan pruning. This trial isbeing repeated this year with slightly different treatments and hopefully this will gosome way to answering our questions.

40

Number of Flowering Terminals (out of 8)C

ount

012345678

Cou

nt

012345678

Date

18-J

ul

25-J

ul

1-Au

g

9-Au

g

15-A

ug

29-A

ug

6-Se

p

12-S

ep

20-S

ep

2-O

ct

10-O

ct

17-O

ct

Cou

nt

012345678

JitleeR167

Null Prune (Harvest)

Prune 1 (February)

Prune 2 (April)

Figure 11. Number of Flowering Terminals

RAMBUTAN, MANGOSTEEN AND DURIAN INDUSTRY STRATEGICPLAN

Y Diczbalis, T K Lim

The tropical fruit industry is in its infancy, particularly for crops such as rambutan,mangosteen and durian. Research agencies such as DPIF, QDPI and CSIRO havesupported plant introduction and agronomic research on these crops, however, thelevel of support has been limited by funds available. A commonwealth funding bodyknown as the Rural Industries Research and Development Corporation (RIRDC) hason its agenda the financial support of new plant industries. The organisation calls forresearch proposals in October each year and funds a small proportion of them. Unlike

41

other research funding organisations RIRDC will consider funding projects withoutindustry contributions.

The horticulture division of DPIF has been active in gaining RIRDC funds forresearch (eg. rambutan - irrigation, durian - productivity, Centralian flowers,asparagus). In October 1995, two proposal were submitted to RIRDC for detailedresearch work on rambutan (rootstock - scion interactions), and mangosteen (cropphenology, rootstock, water relations, nutrient standards). A project on durian wassubmitted by J and A. Zappala, durian growers in North Queensland, in conjunctionwith DPIF and QDPI on plant selection, nutrient standards and agronomic practices.RIRDC’s response to the rambutan and mangosteen proposals was generallyfavourable, however, they stated that these new tropical crops required an improvedapproach to research funding and that an industry strategic plan was required.RIRDC invited DPIF to submit a full proposal for the development of industrystrategic plans rather than a specific research project. RIRDC’s response to the durianproposal was that the initial project should be expanded to include the development ofan industry plan. In all cases project leaders were requested to liaise with theircounterparts in other organisations. The DPIF funded a visit by the authors to northQueensland to discuss the project submission with the QDPI and the industry. Ourproposals were well received and the Qld. industry supported our submission.

Strategic Plan ProposalAfter consultation with local and interstate participants three proposals wereforwarded to RIRDC for rambutan, mangosteen and durian. The rambutan andmangosteen projects were for the development of strategic plans while the durianproposal (administered by J and A Zappala) included a strategic planning component.The strategic plan development process is as follows;• establish working groups (industry, researchers, transport and market agents)• establish database on growers, varieties and tree numbers• begin a quarterly newsletter which includes grower news, market information and

translations of overseas research papers• regional meeting to document problems and R&D proposals• national workshop to review past research, current problems, industry strengths

and weakness and R&D needs• prioritise R&D• document and promote the industry plan

To reduce the costs of the strategic planning process, which is planned to occur over12 months from July 1996 to June 1997, the three proposals put in a joint budget forthe planning process. This allows more efficient use of monies for staging of thenational workshop and newsletter production. However each of the individual cropsmaintains its independence and hence will have its own industry development plan.We hope to hear by the end of May 1996 if the project proposals have beensuccessful.

42

RAMBUTAN FRUIT BROWNING AND PACKAGING

M Landrigan

Detailed studies on rambutan have investigated the primary reasons for their rapiddeterioration. These being, the drying out of the spinterns followed by the skin andmechanical damage to the spinterns causing further fruit damage. A range of optionsto maintain quality and extend the storage life of rambutan have been considered.Harvesting at optimum maturity, careful handling and storage at 10-12 °C in boxesand liners or an overwrapped punnet system will give an effective storage life of up totwo weeks.

These results have been extended to growers in the form of both seminars and anAgnote (No. 648). It is expected the benefits of this research will be in returns togrowers from increased demand for rambutans by consumers. This increased demandis expected to result from:-consumers willing to pay more for a more attractive product with a longer shelf life-more retailers willing to stock rambutans or to stock consistently because of longershelf life-retailers may accept lower retail mark ups due to lower costs.

RAMBUTAN PHENOLOGY AND NUTRITION

T K Lim, L Luders

Since 1991, leaf and soil samples have been collected from various rambutan orchardsin the Darwin rural area. Analysis of the data has shown the nitrogen (N), phosphorus(P) and potassium (K) requirements differ during vegetative flushing, flowering andfruiting periods.

Two small-scale preliminary trials were conducted at Coastal Plains Research Stationand a grower’s property in 1993 and 1994 to determine the effect that NPK has onyield. A lack of NPK fertiliser during fruit development decreased yield in bothcases.

In 1995, a large-scale trial involving eight fertiliser treatments with four replicationswas established at a grower’s property using the cultivar “R167”. The aim of the trialwas to determine the effect of NPK fertilisation during flowering and fruitdevelopment on:• total yield;• total fruit number, fruit drop and retention;• fruit quality, including size, flesh recovery ratio, flesh firmness and BRIX;

and

43

• leaf nutrient concentration and soil nutrient levels. Prior to flowering, complete fertiliser was applied to all trees and weedmats wereplaced under trial trees to collect fallen flowers and fruit until harvest. Flowers andfruit were collected on a weekly basis and dried. The fruit was classified into fourcategories: <6.25 mm, 6.25 mm to 2 cm, 2 cm to 3 cm and >3 cm. Weights andnumbers were determined for each category. Flowers were included with the fruit inthe category <6.25 mm.

Flowering commenced in July and fruit set was visible in August. The eight fertilisertreatments were applied in September and October. The treatments were: plus NPK(+NPK), minus NPK (-NPK), N alone, P alone, K alone, N and P, N and K, and P andK. Harvest began in mid-December and finished at the end of January. Leaf and soilsamples were collected at the end of July, September, November and January.Weekly growth measurements were recorded from tagged floral and/or vegetativeshoots on all trees. Analysis of the data has shown no significant effect from thefertiliser treatments (Table 17). The data did indicate that yield can be influenced byother factors that were recorded in the trial.

Table 17. Effect of NPK fertilisation on rambutan fruit yield and numberTreatment Canopy area Total Fruit

WtAdj Total

FruitTotal Fruit

No.Adj

TotalFruit

(m2) (kg) Wt (kg) No. +NPK 29.88 54.85 56.06 1508 1509 -NPK 27.46 42.45 46.08 1240 1244

N 29.00 53.30 55.40 1594 1596 P 28.96 52.23 54.36 1529 1531 K 30.21 39.63 40.51 1056 1057

NP 31.09 69.38 69.38 2121 2121 NK 29.18 57.40 59.31 1558 1560 PK 25.98 52.68 57.79 1615 1620

The first influence on yield is fruit drop. There is negative correlation betweenharvest weight and fruit drop weight, ie. the higher the fruit drop from a tree, thelower the yield. Although the yield is lower, the remaining fruit can be larger in size.

Panicle and vegetative shoot growth were not significantly different betweentreatments. A negative correlation was found with shoot growth and the number offloral panicles harvested which indicates that yield can be reduced if the tree has toomany vegetative shoots. Total canopy area is important for yield as higher canopyareas generally had higher yield. Trees which had larger canopy areas also had largertrunks and this occurred in the older trees in the trial.

A high positive correlation of 0.97 was found when comparing the average total fruitharvest weight with average total number harvested. The minus NPK and K alonetreatments gave the lowest average total harvest weight and number but these werenot significantly different from the other treatments.

44

Leaf levels of N, P and K changed between the sampling months but no significanttreatment effect was evident. N and K levels decreased during fruit developmentwhile P is lower during flowering. Soil N, P and K levels also change with samplingmonth and no significant treatment effect was found. N and P soil levels increasedslightly while K levels decreased during the trial. From this, P levels appear todecrease with flowering and N and K decrease with fruit development.

Although this trial was conducted on a large scale, no treatment effects weresignificantly different. Increase in canopy area and trunk diameter increase yield asdoes decreasing the amount of fruit drop. P levels may be important for floweringand N and K levels may need to be high during fruit development to increase yield.

ASSESSMENT OF RED FLESH AND OTHER RECENTLY INTRODUCEDGRAPEFRUIT CULTIVARS IN CENTRAL AUSTRALIA.

G Kenna, K Young, N Isgro

Redflesh grapefruit are gaining in popularity throughout the world as a highlypalatable citrus fruit. The older style white fleshed cultivar, Marsh has beensuperseded by the new highly pigmented fruit. Western European markets have beencreating a demand for these fruit with France, Germany and the United Kingdomleading consumer demand.

This demand has also been growing in Asia. The Australian HorticulturalCorporation (AHC) has indicated that there is the potential in the near future forAustralia to export up to 100,000 tonnes of redflesh grapefruit to these countriesincluding Japan.

A national project which is funded by the Rural Industry Research and DevelopmentCorporation (RIRDC) has been established to introduce these redflesh selections anda white flesh cultivar, Oroblanco into established citrus production areas and thoseareas with potential for development throughout Australia.

Information gathered from both replicated trial plantings and demonstration plantingswill be assessed to determine which cultivars are best suited to particular areas. Theproject is being coordinated by Mr Peter Gallasch, Senior Research Scientist, Citrus,South Australian Research and Development Institute.

Cultivars included in the assessment are as follows;Red flesh:• Henderson• Ray Ruby• Rio Red• Star Ruby

Pink flesh:• Ruby

White flesh:• Oroblanco

45

• Marsh

A replicated trial planting was established at the Arid Zone Research Institute inAugust 1995. All cultivars are replicated on two rootstocks, Swingle and Carrizo.Trial layout is a randomised complete block design (RCBD) with 14 treatments and 4replicates.

A demonstration planting consisting of 14 trees was established at Ti Tree ResearchFarm in August 1995. A similar demonstration planting is to be established in theTennant Creek region in September 1996.

During the 1995-96 growing season it was observed that some varieties reactedadversely to the environmental conditions. Star Ruby and Henderson had slowergrowth rates and leaves were bleached. They appeared to exhibit stress symptomsthrough the hot summer months. These growth patterns were evident on bothrootstocks and at both planting locations.

EVALUATION OF A RANGE OF STONEFRUIT TYPES AND CULTIVARSON PEACH-ALMOND HYBRID ROOTSTOCK FOR COMMERCIALPRODUCTION IN CENTRAL AUSTRALIA.

G Kenna, J Mansfield, K Young, N Isgro, C Ellis

At present there are no commercial plantings of stone fruit in the Alice Springsregion. Though it is unlikely that stone fruit could be produced as early as the coastalareas of Northern NSW or the Atherton Tableland in North Queensland, this wouldnot matter as there appears to be good market potential for Central Australianstonefruit in markets such as Adelaide, and the major Northern Territory cities - AliceSprings, Katherine and Darwin. In addition there is some export potential into SouthEast Asia.

Research plantings to assess the potential for dessert stonefruit production in CentralAustralia have been established in this area in the past. Most of these initially grewwell and produced heavy crops but then became unthrifty and only had a short lifespan. This was mainly due to the unsuitability of the rootstock available at the timefor Central Australian conditions. A new rootstock cultivar named Titan (apeach/almond hybrid also known as Bright’s Hybrid) has recently been introducedfrom the USA. This rootstock is reputed to have a tolerance to high soil temperatures,high pH and nematodes, the problems identified as having caused the demise of theearlier plantings.

A planting of this rootstock has been established at AZRI and some have already beenbudded with selections of peach and nectarine including Flordagold, Flordaglo,Dessert Red, 6-3 and 84-16. These trees are growing well and the rootstock appearsto be able to handle the growing conditions. In the near future more trees will bebudded with selections of peach, nectarine and plum. A majority of the cultivars arelow chill selections bred by Wayne Sherman. It is also intended to trial some patented

46

medium chill selections. It is envisaged that the trees currently budded will carry theirfirst crop in 1997.

EVALUATION OF A RANGE BUNCH COVERS TO REDUCE RAINDAMAGE IN DATES


The occurrence of rain on date fruit as it nears maturity can cause considerabledamage including cracking, checking and mould development. This can cause adowngrade in fruit quality or render the fruit unmarketable. In addition losses canoccur due to birds and vermin. Therefore it desirable to find a cover to place over thebunches to protect them during the fruit maturation period.

At the AZRI bunches made from a range of materials including banana bags (plasticbags used for covering banana bunches), muslin, nylon, shadecloth, tyvek (materialused to make disposable overalls) and weedmat are being tested. Bunches are coveredas they near maturity (usually around January). For each bunch, the total fruit weightand the weight of culled fruit were recorded. From these the percentage of culls wascalculated for each bunch. This gave an indication of the effectiveness of the variousmaterials.

In the 1995/96 season, very little rain fell during the fruit maturation period. Only 2.8mm fell in January, 1996, 1.8 mm in February, 2 mm in March, 7 mm in April and norain in May. Therefore very little loss occurred due to rain damage or rots. However,due to the dry conditions mice and birds were prevalent and caused considerabledamage to some bunches. The average percentage culls for each of the cover types onfour different cultivars is presented in Table 18. The denser materials, particularly theplastic banana bags, tended to reduce the losses occurring due to vermin and birddamage. This was particularly apparent in the cultivar Medjool. This is in contrast toprevious years, when summer rain occurred, and the bunches in the banana bagsappeared to suffer more losses due to rots and mould growth because of condensationbuild-up and a lack of air circulation in the bags.

Table 18. The average percentage culls for bunches of four different date cultivarscovered with bunch covers made from various materials.

Cover Type Barhee Deglet Noor Medjool Thoory

Banana bag 60% 75% 24% 73%

Muslin 84% 83% 76% 81%

Nylon 83% 84% 67% 70%

Shadecloth 70% 71% 64% 65%

Tyvek 67% 85% 35% 86%

47

Weedmat 52% 93% 56% 76%

DATE CULTIVAR EVALUATION


In September, 1989 four internationally recognised date cultures were planted in theDahlenburg block at the Arid Zone Research Institute, Alice Springs. The aims of theproject are to assess their performance under Central Australian conditions and todetermine their suitability as potential cultivars for commercial production in thisregion. The four cultivars (Barhee, Deglet Noor, Medjool and Thoory) were importedfrom England as tissue cultured plants. The palms were established in a statisticalplanting comprised of four blocks, with each block containing four randomlydistributed single palm replicates of each cultivar. The palms were planted at aspacing of 7 m between rows and 14 m with-in rows. A single guard row surroundsthe planting.

The palms first started flowering in the 1991/92 season and since then information onthe flowering and fruiting of the cultivars has been recorded. This information ispresently being collated for a publication on date research in Central Australia. Thedata for the 95/96 season is presented in Table 19 and Table 20. All the Barhee andDeglet Noor palms flowered but one Medjool and five Thoory palms did not flower.Not all palms that flowered went on to produce fruit. The average yield of thecultivar Deglet Noor was higher than for the other cultivars but this was because allpalms of this variety carried fruit, whereas the other cultivars had palms which had nofruit. The earliest fruit maturity for all cultivars was the same (26 February) howeverDeglet Noor and Thoory continued to mature fruit for several weeks longer thanBarhee and Medjool.

Table 19. Flower characteristics in the 1995/96 season.

Cultivar Number of palms flowering*

Av. Number of flowers/palm

Barhee 16 8Deglet Noor 16 9

Medjool 15 9Thoory 11 7

Table 20. Fruiting characteristics in the 1995/96 season.Cultivar Number of palms Av. Yield/palms Harvest Period

fruiting* (kg) Earliest LatestBarhee 9 1.18 26 Feb 28 Mar

Deglet Noor 16 6.60 26 Feb 17 Apr

48

Medjool 12 1.36 26 Feb 26 MarThoory 5 1.21 26 Feb 17 Apr

(* Total of 16 palms for each cultivar)

COMPARISON OF IMPORTED TISSUE CULTURED AND OFFSHOOTDATE PALMS


There has been some reservation about whether off-types may occur in tissue cultureddate palms and whether or not all palms produced are “true to type”. Offshootssuckers are the standard method of propagation. Tissue culture offers the possibilityof importing plant material from overseas countries where off-shoots cannot beobtained due to quarantine restrictions. Tissue cultured plants are cheaper to importthan offshoot material and as they are in a sterile medium, they do not requirefumigation. In addition, tissue culture offers a means of rapidly multiplying plantingmaterial within Australia using plant material already here.This project compares tissue-cultured and off-shoot palms of the same cultivar.Depending on availability, tissue-cultured palms produced by two different methodswere used - those from Date Palm Developments, England, produced by a callusmultiplication method and those from the Group of French Research on Date PalmLaboratory, France which were produced using a bud proliferation technique.

For each of the cultivars Medjool, Thoory and Zahidi two palms of offshoots and twopalms produced by each tissue culture method were planted in the Dahlenburg Block,Arid Zone Research Institute, Alice Springs. For the cultivars Barhee and DegletNoor, two offshoots were planted along with four palms from the tissue culturelaboratory in England. For the cultivar Khadrawy two offshoot palms were comparedwith two palms obtained from the French tissue culture laboratory only. Each cultivarwas planted in a single row at a spacing of seven metres between rows and fourteenmetres-in the row. The offshoots and tissue cultured plants from England wereplanted in April 1990 and the tissue culture plants from France were planted in April1991. The two offshoots for each cultivar were planted side-by-side at the northernend of the rows. When present, the French tissue cultured palms were planted side-by-side in the centre of the row.

The palms first started flowering in the 1992/93 season and since then data onflowering and fruiting has been recorded. This information is presently being collatedfor a publication on date research in Central Australia. The data for the 95/96 seasonis presented in Table 21, Table 22 and Table 23. There appears to be few obvioustrends. One outstanding difference was the that average yield of Deglet Noor derivedfrom offshoot material was over five times greater than the tissue cultured palms ofthe same cultivar from England.

49

Table 21. Number of palms flowering for each cultivar in the 1995/96 season.Plant Source Barhee Deglet

Noor

Khadrawy Medjool Thoory Zahidi

Offshoot 2 of 2 2 of 2 2 of 2 2 of 2 1 of 2 1 of 2

Tissue culture - France - - 2 of 2 1 of 2 2 of 2 2 of 2

Tissue culture -

England

3 of 4 4 of 4 - 2 of 2 2 of 2 2 of 2

Table 22. Average number of flowers per palms for each cultivar in the 1995/96season.

Plant Source Barhee Deglet

Noor


Offshoot 9 7 4 3 6 1

Tissue culture - France - - 6 5 9 5

Tissue culture - England 5 5 - 11 13 9

Table 23. Average yield (kg) per palms for each cultivar in the 1995/96 season.

Plant Source Barhee Deglet

Noor


Offshoot 0 12.70 0.01 1.10 0.77 0

Tissue culture - France - - 0.01 0.72 0.45 0.22

Tissue culture - England 0.05 2.36 - 1.66 0.65 0

DATE GERMPLASM COLLECTION AT THE ARID ZONE RESEARCHINSTITUTE, ALICE SPRINGS.


The germplasm collection is made up of a number of male and female cultivarsimported as offshoot material and tissue culture from various international sources.The main objectives of this project are to assess the potential of various date palmcultivars for the Central Australian region and to provide plant material for researchand development purposes.

50

The tissue cultured material was obtained from laboratories in England and France aswell as offshoots from California and offshoots produced on palms at the Arid ZoneResearch Institute (AZRI). The planting of the trial started in April 1990 andadditions have been made as material has become available. A new cultivar Sukkarywill added to the collection in the near future. The palms first started flowering in the1992/93 season. Data on flowering and fruiting of the cultivars has been recorded.This information is presently being collated for a publication on date research inCentral Australia. The data for the 95/96 season is presented in Table 24.

Table 24. Flowering and yield data for the cultivars in the 195/96 season.(Abbreviations: No. = Number, Av. = Average, TC = Tissue Culture, N/A = Notapplicable)

Cultivar Source Planting Date No. of palms flowering

Av. Numberflowers/palm

Av. Yield/palm(kg)

Abu Naringa TC England December 1995 0 of 4 - -Barhee Offshoot California April 1990 1 of 1 17 0Barhee TC England August 1995 0 of 1 - -Barhee Offshoot - AZRI December 1995 0 of 2 - -

Bou Feggous TC France April 1991 3 of 3 3 0Bou Skri TC France April 1991 3 of 3 3 0

Bou Sthammi TC France April 1991 2 of 3 4 0.27Boyer No 11 (Male) TC England April 1990 1 of 1 27 N/A

Dayri Offshoot California April 1990 2 of 2 6 0Deglet Noor Offshoot California April 1991 1 of 1 13 8.50

Fard No 4 (Male) TC England April 1990 2 of 9 2 N/AFard No 4 (Male) TC France April 1991 3 of 4 5 N/AFard No 4 (Male) Offshoot California April 1991 3 of 3 8 N/A

Halawi TC England April 1990 1 of 2 1 0Halawi Offshoot California April 1990 0 of 3 - -Hayany TC England April 1990 5 of 5 6 0.39Hilali TC England April 1990 0 of 1 - -

Jarvis No 1 (Male) TC England April 1990 1 of 1 17 N/AKhadrawy Offshoot California April 1991 1 of 1 2 0

51

Khalas Offshoot California April 1991 2 of 2 3 0Khalas TC England December 1995 0 of 1 - -

Khalas Oman TC England December 1995 0 of 2 - -Kush Zabad TC England December 1995 0 of 2 - -

Medjool Offshoot California April 1991 1 of 1 7 2.93Nabut Saif TC England December 1995 0 of 3 - -

Thoory Offshoot California April 1991 1 of 1 14 0Zahidi Offshoot California April 1990 1 of 1 2 1.65Zahidi Offshoot - AZRI December 1995 0 of 1 - -

Unknown Female TC England April 1990 1 of 1 11 0Unknown Female - August 1995 0 of 3 - -

52

PARLATORIA SCALE ERADICATION

G Kenna, K Young, N Isgro C Ellis, D Kennedy, R Mills, D Leslie

Parlatoria Scale is a major pest of date palms in the Alice Springs area. The scalewhich was introduced into Australia in the early 1900’s and into Central Australia inthe 1950’s threatens the long term viability of the commercial date industry inAustralia. It causes palms to become unthrifty and may also infest fruit. This caneither cause the fruit to be downgraded in quality or render it unsuitable for sale.

The insect has infested two date farms in the region, Mecca Date Gardens and AridGold Farm and plantings at the Arid Zone Research Institute. A large percentage ofpalms growing in and around the Alice Springs town area are infested with the scaleand there are also palms in a number of areas throughout the region which areinfested. In most instances the scale has been spread by the movement of infestedplant material.

A serious attempt to eradicate the scale from plantings at the AZRI, Mecca DateGardens and Arid Gold Farm was commenced in 1991. The program involved:• The provision of assistance to Arid Gold Farm to apply insecticide sprays to all

palms on the property.• The provision of chemical for scale eradication at Mecca Date Gardens and Arid

Gold Farm.• Foliar application of insecticides at three weekly intervals to palms in the

Dahlenburg Block research planting at the AZRI.• Foliar application of insecticides at three weekly intervals and six weekly trunk

injections to palms on De Fontenay Drive at the AZRI.• Three weekly trunk injection with insecticides to mature palms at the• McEllister Block at the AZRI.• Three weekly foliar sprays of insecticide to offshoots held in nursery rows at the

McEllister Block at the AZRI.• Removal of dead and unthrifty leaves from all palms.• Removal and destruction of infested offshoots from palms in the research planting.• Inspection and treatment of all offshoots by immersion in dimethoate before

leaving the AZRI.• Insecticides used for foliar sprays are alternated.

The resources required to conduct such a program over a number of years areconsiderable. Progress in the eradication of the scale is being made. The numbers oflive scale on palms at the AZRI are declining. Scale numbers have also declined atMecca Date Gardens and Arid Gold Farm. A survey to monitor the rate of decline bysampling grower properties and the plantings at the AZRI will be conducted in latespring - early summer. Further methods of eradication will be considered inconsultation with the Entomology Branch at that stage.

53

EVALUATION OF THE EFFECT OF COMBINE® ON BUNCH QUALITY INTABLEGRAPES (SOUTHERN REGION)


While on a visit to research establishments in India, the Director Horticulture DPIF,was made aware of a new generation plant growth regulator which is being researchedin that country. The substance which is sold commercially as Combine®, is a naturallyoccurring brassinosteroid

The chemical Gibberellic Acid (GA) has been used for many years by tablegrapegrowers to improve the berry size and quality of seedless tablegrapes. There are anumber of problems associated with the use of this chemical such as the accuratetiming of spray applications and the effectiveness of the sprays in achieving thedesired results. While increased berry size may be achieved, the effectiveness of sprayapplications for berry thinning and bunch stretching, which is necessary to offset theincrease in berry size, is not always possible. The manufacturer of Combine claimsthat it will increase berry size in tablegrapes independently of GA, yet it also has asynergistic effect when used with that product. Research work in India recommendsthat a small amount of GA be used in combination with Combine® for best results.The product can be used on seedless and seeded varieties.

Preliminary work to assess the potential of Combine® for the Central Australiatablegrape industry was carried out in 1994. The assessment was carried out atTerritory Grapes on the varieties Flame Seedless, Menindee Seedless, Sultana andRed Globe using two methods of application - dipping and hand spraying. Resultsfrom this preliminary work indicated that the use of a Combine®/GA solution has thepotential to improve tablegrape bunch quality in all varieties, particularly when thebunches were dipped. While individually dipping each bunch in solution is therecommended method of application this is considered uneconomical underAustralian tablegrape production conditions.

Further research on the chemical was considered necessary, and in the 95-96 season itwas trialed again at Territory Grapes using two cultivars, Menindee Seedless and RedGlobe.

For Menindee Seedless, treating the bunches with Combine®/GA produced largerbunches than the untreated. However, there was no difference between the method ofapplication and the dipped and sprayed bunches were of a similar size (Table 25). Thesolution had no effect on berry diameter or berry weight as there was no significantdifference between the treatments (Table 25). Therefore it appears that the increase inbunch weight caused by the treatment was due to a greater number of berries perbunch, however this is only an assumption as no measurement was taken of berriesper bunch. If this did occur, it was possibly due to a reduction in the number of berriesshed at the shatter stage of fruit development. This result for Menindee Seedless couldbe of particular importance to the industry. When GA is used alone on this cultivar, it

54

can cause a severe decline in yield in subsequent seasons. The use of Combine® witha very small amount of GA may have the potential to increase berry size and bunchquality without compromising future yields.

One disadvantage of using the solution was that the juice sweetness, expressed asbrix, of the treated Menindee Seedless grapes was reduced. Both the dipped andsprayed grapes had a lower brix reading than the untreated bunches but there was nodifference between the two methods of treatment (Table 25). This reduction in brixmay have been due to the larger bunches and heavier crop load on the treated vines.The heavier crop load on the treated vines may have resulted in a reduction in theamount of sugars in each of the treated berries.

In Red Globe, unlike for Menindee Seedless, treating the bunches withCombine®/GA had no significant effect. The size of the bunches, the diameter andweight of the berries and the juice sweetness were similar between the treated anduntreated (Table 26).

Table 25. In the cultivar Menindee Seedless, treatment with Combine®/GAsignificantly increased average bunch weight and decreased berry sweetnessregardless of the method of application.1

Treatment Av. Bunch Weight(g)

Berry Diameter(mm)

Av. Berry Weight(g)

Sweetness(brix°)

Control 495 b 18.8 a 4.8 a 16.2 aDipped 543 a 19.4 a 5.1 a 14.9 bSprayed 550 a 19.6 a 5.3 a 14.8 b

Table 26. In the cultivar Red Globe, treatment with Combine®/GA had no significanteffect on average bunch weight, berry diameter or weight and juice sweetness. 1

Treatment Av. Bunch Weight(g)

Berry Diameter(mm)

Av. Berry Weight(g)

Sweetness(brix°)

Control 658 a 23.2 a 8.4 a 16.7 aDipped 639 a 22.7 a 8.1 a 16.7 aSprayed 619 a 23.0 a 8.3 a 16.3 a

1 For each parameter, values with the same letter are not significantly different.

For Menindee Seedless, both methods of application gave similar results. Therefore,the efficiency of treatment application would be an important factor in determiningwhich is the best and most cost effective way of using Combine®/GA The samevolume, of Combine®/GA, - 4 litres - was used for both methods of application.However, the amount of labour required to apply the treatments varied considerably.The time required to treat 24 vines by dipping was two hours. The time required toapply the treatment by hand spray was 20 minutes. At standard pay rates for casuallabour of $12 per hour the cost of treating 24 vines by dipping bunches was $24, ($1per vine) compared with the cost of spray application of $4 ($0.17 per vine) for theequivalent number of vines. Taking this into consideration, spraying would be thebest commercial method of Combine®/GA application in the Alice Springs region.Further work will be conducted to determine if application of the chemical usingconventional spray units is just as effective as hand spraying.

55

USING CHEMICAL TREATMENTS TO BREAK GRAPEVINE DORMANCY(SOUTHERN REGION)

G Kenna, K Young, N Isgro, C Ellis (DPIF) N Dokoozlian, D Luvisi (Universityof California)

Although grapevines do not require long cold winters for dormancy and budburst tooccur, problems can result in years when the winter months are quite mild. In theseyears, the vines tend to drop all or most of their leaves however as temperaturesincrease in late winter the budburst may be reduced, prolonged or irregular. This canresult in uneven vine vigour and may delay the maturity of bunches on shoots whichwere delayed in budburst. This can present management problems such as timing theapplication of sprays such as giberellic acid which is essential for the production ofquality fruit. Market returns may also be reduced when early maturity is a keymarketing advantage.

A compound known as hydrogen cyanamide was found to break dormancy ingrapevines and alleviate many of the problems associated with uneven budburst. Thischemical has been manufactured and marketed as Dormex®. It has been used in grapeproduction areas throughout the world where climatic conditions are unlikely to beconducive to a satisfactory budburst or where early maturity creates a marketingadvantage.

There are however a number of disadvantages associated with the use of thischemical. The user hazard is high and requires stringent adherence to the safetyprecautions and directions for use. The chemical is expensive, especially when thehigher of the recommended application rates are required, or when very large areas ofvines require treatment. In addition where vineyards are located in intensivehorticultural areas where other fruit crops are grown a very small amount of driftassociated with the application of Dormex® can cause considerable damage to nontarget crops. Such is the case in California where vineyards are located close to citrusplantings and damage to this crop may result after a Dormex® application to vines.

It was for these reasons that the Californian grape growers requested researchers tolook for alternatives to the use of Dormex®. Trials conducted in California in 1994-1995 indicated that liquid calcium ammonium nitrate (CAN-17®) was an effectivedormancy breaking agent when applied in conjunction with another chemical knownas Armobreak®. Field trials were established in Central Australia in 1995 to assessdormancy breaking treatments. The trials were a co-operative effort between Dr NickDokoozlian (Dept of Viticulture and Enology, University of California, Davis), MrDonald Luvisi (University of California Extension, Kern County) and DPIF staff inthe Alice Springs region.

Two separate experiments were conducted at Territory Grapes on the cultivar RedGlobe. Both experiments were arranged in a randomised complete block, split plotdesign. The treatments were replicated 8 times using 3 vine plots with the middle vinein each plot used for data collection. The treatments were applied using a hand-heldspray wand. All buds on spurs and cordons were sprayed with the solution till runoff.

56

Approximate rates were 1 litre of solution per vine or 1,000 litres per hectare. Thevines were then monitored twice weekly for seven weeks.

The first experiment examined the effects of several commercial surfactants on theefficacy of Dormex® and CAN-17®. The following treatments were applied:

1. Dormex® (1% v/v) + CAN-17® (25% v/v) + Armobreak® (2% v/v) 2. Armobreak® (2% v/v) 3. Agral® (2% v/v) 4. Spray Mate Li 700® (2% v/v) 5. Chem Wet 700® (2% v/v) 6. Synertol® (2% v/v) 7. Untreated control 8. Dormex® (1% v/v) + Armobreak® (2% v/v) 9. Dormex® (1% v/v) + Agral® (2% v/v)10. Dormex® (1% v/v) + Spray Mate Li 700® (2% v/v)11. Dormex® (1% v/v) + Chem Wet 700® (2% v/v)12. Dormex® (1% v/v) + Synertol® (2% v/v)13. Dormex® (1% v/v)14. CAN-17® (25% v/v) + Armobreak® (2% v/v)15. CAN-17® (25% v/v) + Agral® (2% v/v)16. CAN-17® (25% v/v) + Spray Mate Li 700® (2% v/v)17. CAN-17® (25% v/v) + Chem Wet 700® (2% v/v)18. CAN-17® (25% v/v) + Synertol ® (2% v/v)19. CAN-17® (25% v/v)

When surfactants were applied alone only the surfactants ArmoBreak® and Chem Wet600® advanced budbreak compared to the untreated control. All surfactants improvedthe efficacy of Dormex®, with Agral® and Chem Wet 600® providing the best results.In contrast, only Armobreak® and Chem Wet 600® significantly improved the efficacyof CAN-17®.

The second experiment examined the effect of the rate of CAN-17® applied with andwithout the surfactant Armobreak®. The following treatments were applied:

1. Untreated 2. Dormex® (4% v/v) 3. Armobreak® (2% v/v) 4. Dormex® (1% v/v) + Armobreak® (2% v/v) 5. CAN-17® (10% v/v) 6. CAN-17® (20% v/v) 7. CAN-17® (30% v/v) 8. CAN-17® (40% v/v) 9. CAN-17 (50% v/v)10. CAN-17® (10% v/v) + Armobreak® (2% v/v)11. CAN-17® (20% v/v) + Armobreak® (2% v/v)12. CAN-17® (30% v/v) + Armobreak® (2% v/v)13. CAN-17® (40% v/v) + Armobreak® (2% v/v)14. CAN-17® (50% v/v) + Armobreak® (2% v/v)

57

When Armobreak® was not used, budbreak rate generally increased with increasingCAN-17® concentration. However, the addition of Armobreak® improved the efficacyof all CAN-17® treatments, and budbreak was most rapid for vines treated with 40%CAN-17® +2 % Armobreak®.

In these experiments 1% Dormex® + 2% surfactant and 40% CAN-17® + 2%Armobreak® provided similar results to the current commercial treatment of 4%Dormex®. However, it will be necessary to repeat these experiments over a number ofseasons to assess these rate interactions. At Territory Grapes, a smaller scale trialusing Dormex®, CAN-17® and a limited number of surfactants is being conducted inthe 1996 season.

Preliminary results from a similar experiment conducted in California in 1996 werevariable. There were problems encountered in the Coachella Valley after one of thelowest winter chills in history. Ongoing liaison between DPIF and researchers in theUnited States in all aspects of table grape production will continue.

ROCKMELON AND HONEYDEW TRIALS IN THE TOP END


Introduction

In the past, rockmelons have been a major crop in the Top End and a great deal of R& D has been carried out on them. On the other hand, honeydew melons, have onlyever been a minor crop and apart from a few small selection trials little attention hasbeen paid to the crop.

The expected arrival of two Burdekin melon growers and exporters into the district in1996, who will use Darwin to grow honeydews to extend their Queensland operations,has heightened interest in the crop. Winter temperatures at Ayr are too cool in winterto achieve adequate fruit size and quality of honeydews to supply their south eastAsian market requirements. It was agreed that the four honeydew cultivars currentlygrown successfully in the Burdekin should be evaluated under Darwin conditions.Dry season temperatures near Darwin appear to be ideal for good market sizehoneydews which is difficult to achieve in the cooler climate of Katherine. It was alsodecided to evaluate a number of the latest rockmelon introductions with knownperformers to keep up to date with recent developments. Although the Darwin DPIFmelon program was discontinued in 1992, due to the collapse of the industry, thegrowers advisory group decided that DPIF Annual Crops Section should keep abreastof developments in the event of a resurgence of the industry in the Top End.

58

Methodology

• Varietal scheduling over 2 planting dates to − Trial 1 Harvest at the end of July− Trial 2 Harvest at the end of September

• Cultivars

Rockmelons Honeydews

Dubloon DewcrispEastern Star White MistMission HoneymoonFlinders DewetteStirlingIvanhoe

Results

Shown in Tables 27 and 28

• Rockmelons

Trial 1Eastern Star performed well in Trial 1 under cool conditions and is well suited to thistime slot in Darwin. Dubloon is a very versatile melon and can be grown well under arange of conditions. Mission could not size up and is more suited to hot weatheralthough its quality was excellent. Ivanhoe was the best performer of the threerecently released cultivars.

Trial 2The plants in this trial experienced very hot weather in early September and thisaffected cultivar quality. Eastern Star grew too large and the seed cavity opened upwhile Dubloon was consistent with good quality. Mission also had excellent internalquality but fruit size was small. Flinders improved over Trial 1 while Stirling andIvanhoe could not handle the warmer conditions.

Eastern Star is an outstanding melon and is ideal for the mid-season period. Missionis best suited to early and late planting’s where it can tolerate high temperatureconditions.

• HoneydewsDewette is a round, attractive, good quality melon with uniform size and shape, highsugar content and good disease tolerance. It was the outstanding cultivar in bothtrials. Dewette and White Mist are a new type of honeydew, bred for concentratedfruit set and for once over harvesting. These new lines help overcome one of the

59

biggest problems with honeydews - the determination of fruit maturity in the field.White Mist has a very good, dense bush cover and offers excellent protection to thefruit from sunburn. It matures quickly and slips quickly if over-mature. Also thepresence of growth cracks and a tendency to split reduced its potential in these trials.

Trial 1The fruit in this trial matured in late July under cool conditions and very low relativehumidity. With the exception of White Mist the other three honeydew cultivarsexperienced leaf wilting during the warmest part of the day but recovered in midafternoon although soil water content was adequate. Discolouration of the fruit fromsunburn and downgrading of the fruit was the result.

Trial 2Although the plants in this trial were grown under much hotter conditions, leaf wiltingdid not occur to the name extent as in the cooler weather. Further work on honeydewto investigate this phenomena is planned for next year.

60

Tabl

e 27

. R

esul

ts o

f Mel

on V

arie

ty T

rial N

o. 1

- A

vera

ge o

f 2 R

eplic

ates

- D

ate

Sow

n 10

/5/9

5

Mar

ket

Ave

.Mar

ket

No.

Mar

ket

Ave

.A

ve.

Day

s to

Var

iety

Seed

Larg

e*Fr

uit

Med

ium

*Fr

uit

Smal

l*Fr

uit

Plot

Yie

ldFr

uit S

ize

Frui

t per

Deg

rees

Fles

hFi

rst

Mar

ket

Co.

Wt.

%Fr

ui tW

t.%

Frui

tW

t.%

Frui

t(L

+M) K

g(L

+M)K

gPl

ant

Brix

Firm

nes

sH

arve

stA

sses

smen

t

DU

BLO

ON

north

kin

g12

.05

20.0

26.4

562

.84.

9017

.238

.51.

332.

410

.51.

276

GO

OD

EAST

ERN

STA

Rno

rth k

ing

33.3

061

.315

.10

38.7

--

48.4

01.

562.

611

.92.

176

V. G

OO

D

MIS

SIO

Nne

w w

orld

--

22.6

843

.520

.70

56.5

22.6

81.

131.

710

.61.

173

GO

OD

FLIN

DER

Sne

w w

orld

3.25

4.2

42.1

075

.08.

6520

.845

.35

1.19

3.2

9.1

1.3

75FA

IR

STIR

LIN

Gne

w w

orld

35.1

251

.420

.78

48.6

--

55.9

01.

153.

18.

91.

273

FAIR

IVA

NH

OE

sout

h pa

cific

2.37

1.8

43.8

067

.813

.78

30.4

46.1

71.

183.

29.

81.

674

GO

OD

DEW

CR

ISP

north

kin

g26

.60

42.4

23.8

557

.6-

-50

.45

1.53

2.7

10.5

2.1

77FA

IR

WH

ITE

MIS

Tne

w w

orld

31.3

759

.314

.50

40.7

--

45.8

71.

702.

311

.21.

873

FAIR

HO

NEY

MO

ON

new

wor

ld29

.22

53.3

16.1

043

.30.

903.

445

.32

1.56

2.4

10.7

2.2

77FA

IR

DEW

ETTE

new

wor

ld10

.10

18.8

31.4

075

.02.

356.

241

.50

1.38

2.5

10.6

1.6

77G

OO

D

* La

rge

> 1.

5kg

M

ediu

m 1

.0 -

1.5k

g

Sm

all <

1.0

kg

61

Tabl

e 28

. Res

ults

of M

elon

Var

iety

Tria

l No.

2 -

Ave

rage

of 2

Rep

licat

es -

Dat

e So

wn

23/6

/95

Mar

ket

Ave

.Mar

ket

No.

Mar

ket

Ave

.A

ve.

Day

s to

Var

iety

Seed

Larg

e*Fr

uit

Med

ium

*Fr

uit

Smal

l*Fr

uit

Plot

Yie

ldFr

uit S

ize

Frui

t per

Deg

rees

Fles

hFi

rst

Mar

ket

Co.

Wt.

%Fr

uit

Wt.

%Fr

uit

Wt.

%Fr

uit

(L+M

) Kg

(L+M

)Kg

Plan

tB

rixFi

rmne

ssH

arve

st

Ass

essm

ent

DU

BLO

ON

north

kin

g19

.38

42.3

19.1

857

.7-

-38

.56

1.48

2.2

10.4

1.6

74G

OO

D

EAST

ERN

STA

Rno

rth k

ing

39.3

593

.02.

027.

0-

-41

.37

1.92

1.8

10.9

2.5

76G

OO

D

MIS

SIO

Nne

w w

orld

--

27.2

063

.911

.75

36.1

27.2

01.

181.

911

.41.

272

GO

OD

FLIN

DER

Sne

w w

orld

13.2

028

.625

.75

71.4

--

38.9

51.

392.

311

.92.

473

GO

OD

STIR

LIN

Gne

w w

orld

42.9

581

.86.

5518

.2-

-49

.50

1.80

2.3

9.1

1.4

73FA

IR

IVA

NH

OE

sout

h pa

cific

14.4

725

.730

.75

69.7

1.40

4.6

45.2

21.

442.

611

.22.

173

FAIR

/PO

OR

DEW

CR

ISP

north

kin

g45

.30

81.0

7.20

19.0

--

52.5

01.

812.

412

.62.

077

FAIR

/PO

OR

WH

ITE

MIS

Tne

w w

orld

42.4

578

.36.

7521

.7-

-49

.20

2.10

1.9

12.1

1.5

73FA

IR

HO

NEY

MO

ON

new

wor

ld30

.35

59.6

13.7

040

.4-

-44

.05

1.69

2.2

13.5

1.9

77FA

IR

DEW

ETTE

new

wor

ld14

.67

29.3

27.0

770

.7-

-41

.74

1.44

2.4

13.1

1.7

77FA

IR/G

OO

D

62

* La

rge

> 1.

5kg

M

ediu

m 1

.0 -

1.5k

g

Sm

all <

1.0

kg

63

CASHEW BREEDING LINE ASSESSMENT

G Foord, M Smith, M Hoult, S McAlister, J Bright, S Smith

Cashew research in Katherine is concentrated on a collection of hybrids planted atKing Producers’ (Ian & Heather Curtis) Venn block, 20 kilometres south ofKatherine. A total of over 800 trees consisting of about 450 different cashew hybridswere planted in 1992 as part of the DPIF, QDPI and CSIRO hybrid evaluationprogram. In January 1995 Katherine DPIF and Ian Curtis agreed to jointly managethis planting and make assessments as required.

Many trees display good vigour and the 1995 yield assessment shows potential forhigh yields (see table). Yield was visually assessed in October, each tree was rankedfrom 0 to 5 (5=highest yield). Nuts from all trees ranked 4 or 5 were collected, plus aselection of each of the lower ranked trees. There was good correlation between nutnumber per tree and ranking (Adj R-sq 0.5633) and between kg/tree and ranking (AdjR-sq 0.6635). This indicates that visual assessment is a useful tool for determiningcashew yield in large plantings of genotypes.

1995 yield of the best ten cashew hybrids is presented in Table 29.

Table 29. 1995 Yield of cashew hybridsCodeident.

kg./tree(nut-in-shell)

nut weight g.(nut-in-shell)

nutnumber/tree

ranking(visual)

1161 8.803 5.86 1502 51199 7.96 5.91 1347 41320 7.885 4.19 1882 41873 7.381 5.6 1318 41542 6.929 8.13 852 31576 6.622 3.77 1756 41483 6.38 6.21 1027 41540 6.124 5.85 1047 41034 5.812 5.46 1064 41056 5.787 6.56 882 3.5

Early in 1995 it became clear that management systems developed elsewhere did notnecessarily suit Katherine conditions. Pest management emerged as a priority. Themain cashew foliage pests experienced in Katherine have been the mango tip borer(MTB) (Penicillaria jocosatrix), Helopeltis bug (Helopeltis sp.) and the fruit spottingbug (Amblypelta lutescens).

MTB was a persistent problem from February to May in 1995. Chemical control andthe use of Bacillus thuringiensis (Biobit®) proved effective however infestations re-occurred as the cashews continued to flush during this period.

Mastotermes or giant termite (Mastotermes darwiniensis) has caused significantlosses in this planting. Details are reported in a separate article in this bulletin.

64

MANAGEMENT TECHNIQUES FOR CASHEW

G Foord, M Smith, M Hoult, S McAlister, J Bright, S Smith

Since mango tip borer (MTB) larvae normally feed on flushing foliage (Hood, 1994),we decided to attempt to limit flushing in the February to April period by withholdingwater and fertiliser applications from the beginning of the wet (December) until earlyMay. We believe that fertiliser applications and irrigation through this period in 1995encouraged vegetative flushes not essential for fruit and nut development. Goodyields were recorded despite severe damage to these flushes.

Total macro-nutrient applications would be consistent with the N3P3K3 scheduledeveloped by Richards (1993) but, rather than follow ‘The little and oftenprinciple...’(Richards, 1993), we adopted a strategy that would encourage new growthat times of the year when pest pressure was low (see Figure 12). Nitrogen was appliedin May, June and December, potassium in May and December and phosphorus inDecember only. This approach should promote more uniform flushing and floweringand high yields with reduced reliance on spraying. The more important flushes wouldthen be protected through careful monitoring and insecticide use.

Figure 12. Cashew Phenology and Management, Katherine

We imposed this management strategy on the hybrid collection at Curtis’ inDecember 1995. NPK plus trace elements were applied in December and rainfall wasnot supplemented with irrigation. No major insect problems were encountered,however it was a relatively dry ‘wet’ season.

As expected and in contrast to 1995, very few new flushes emerged between Februaryand May 1996. Some MTB were detected, but no real damage occurred. Although noirrigation or fertiliser was applied during this period the trees did not appear to bestressed and showed no deficiency symptoms. The trees responded well to the

65

recommencement of irrigation and application of fertiliser in May and June. Thesubsequent vegetative and floral flushes appear more uniform than in 1995.Dimethoate was applied (two sprays ten days apart) to control helopeltis in June andAugust. It now remains to be seen if high yields can be achieved using this modifiedsystem.

AcknowledgmentWe thank Ian and Heather Curtis for their continued support of this project.

References

Hood, S, (1994). The Mango tip borer a major pest of cashew. Seventh AnnualCashew Workshop May 17, 1994. p 69.

Richards, N.K. (1993). Cashew research in Northern Territory Australia. NTDepartment of Primary Industry and Fisheries, Technical Bulletin No. 202. pp 5, 37

MASTOTERMES RESEARCH IN KATHERINE

G Foord, M Smith, L Miller, M Neal, M Hoschke

Mastotermes or giant termite (Mastotermes darwiniensis) caused heavy losses in acashew hybrid collection at the Venn blocks south of Katherine. In 1995 DPIF staff atKatherine and the Joint Termite Group in Darwin trialed a number of aggregationtechniques, baits and alternative toxicants in an effort to control mastotermes anddevelop a termite management program.

In one experiment, our aim was to determine the level of repellence of variousconcentrations of boric acid added to sawdust/agar/sugar baits for the control ofMastotermes. Laboratory trials with boric acid had shown >90% mortality of laboratorygroups, after an initial delay period, over a range of concentrations. Boric acid thereforemeets several criteria of Stringer et al. (1964) for effective toxins for social insects.

Baits containing 10 g/L agar, 10 g/L sugar, 5 g/L boric acid and sawdust were fieldtested at Katherine with mastotermes actively feeding one week after bait placement.Because mastotermes colonies can be very large, as many as 5 million termitesweighing 200 kg (Miller 1994), large amounts of boric acid, in bait form, are required tocontrol these colonies. If the 5 g/L boric acid concentration can be increased, fewer baitswill be required. Increasing the sugar concentration to 20 g/L, may allow higher boricacid concentrations to be accepted in bait form.

Treatments included (1.) a ‘control’ (containing no boric acid) and (2.) a ‘standard’ with10 g/L sugar and 5 g/L boric acid (previously tested), replicated 4 times in a randomisedblock design. The treatments, in solution combined with sawdust, were;

1. 20g/L sugar 10g/L agar no boric acid

66

2. 10g/L sugar 10g/L agar 5g/L boric acid3. 20g/L sugar 10g/L agar 5g/L boric acid4. 20g/L sugar 10g/L agar 10g/L boric acid5. 20g/L sugar 10g/L agar 20g/L boric acid6. 20g/L sugar 10g/L agar 40g/L boric acid

Materials and MethodsSugar, agar and boric acid was added to 1 litre of distilled water. It was then stirred on aheated magnetic stirrer until completely dissolved. 400 g of sawdust was added to forma paste that became a firm block when cooled. 250 g of bait was put into 250 ml ‘take-away’ containers, 4 were placed in the field and 1 was oven dried at the end of theexperiment to determine the amount of bait consumed.

Cashew trees infested with mastotermes were identified. Affected trees were mapped toallow for an effective experimental design. A limb of the trunk was cut from eachselected tree and the bait placed in the container upside-down over the exposedMastotermes galleries. Then covered with aluminium foil and secured with PVC tape.

Every two weeks after installation, part of the aluminium foil was carefully removed toexpose the bait container and recorded if Mastotermes were actively feeding. All baitswere removed 8 weeks after installation, oven dried and weighed to determine howmuch bait had been consumed.

ResultsBoric acid baits were installed on 12/09/95, checked on 28/09/95 and removed on06/10/95. Baits were removed early because some treatments were almost completelyconsumed. All baits in treatments 1, 2, and 3 were active on 28/09/95 and 06/10/95. Allbaits in treatment 6 were inactive. Treatments 4 and 5 showed a mixed reaction with nocontinuous activity observed.

Dry weight of baits at removal are presented in Table 30.

Table 30. Dry weight of baits

Treatment Mean dry weight(g)

SD Numberactive28/09/95

Numberactive06/10/95

1 18.60 4.09 4 42 61.64 25.06 4 43 100.94 39.63 4 44 108.41 68.73 1 25 65.54 14.78 1 26 64.49 15.36 0 0control 60.00

Using the dry weight of a bait can be misleading as mastotermes often replace the bait,as it is consumed, with soil. The dry weight of active baits may exceed those ofuntouched baits.

67

Therefore, activity should also be considered. Treatment 1 (no boric acid) was activethroughout and had the lowest dry weight, with little soil added by the mastotermes.This indicates some repellence in treatments 2 and 3 that, although remaining active,they were not consumed as readily as treatment 1.

In October 1995, when the replicated trial was removed, 48 baits with 0.5% boric acidwere installed in the 4.5 hectare orchard. These were replaced as required.Throughout 1995 between eight and fifteen trees per month were lost to mastotermes.In January 1996 mastotermes was still active and trees were being lost at the samerate as before treatment. We assumed that the amount of boric acid being consumedwas not enough to have an impact on such a large colony. A total of 30 active siteswithin the orchard were then treated with Mirant® (a commercially available productcontaining mirex). This appears to have been effective as no further losses haveoccurred since treatment.

This exercise shows some of the difficulties involved with mastotermes research onhorticultural properties and our reliance on Mirant®. It also highlights the importanceof current mastotermes research by the Joint Termite Group in Darwin and thepotential impact on further development of commercial tree crops in northernAustralia.

Acknowledgment

We thank Mr Ian Curtis for his support and patience.

Reference

Stringer Jr, C. E., Lofgren C. S., and Bartlet, F. J. (1964). Imported fire ant toxic baitstudies: evaluation of toxicants. J. Econ Entomol. 57, 941-5

Miller, L. Mastotermes in cashew. Seventh Annual Cashew Research andDevelopment Workshop, May 17, 1994

BAMBOO RESEARCH 1995

K Blackburn and M Traynor

The bamboo research project is partially funded by RIRDC and is an Australian jointresearch investigation combining inputs from:

• The University of Central Queensland, Rockhampton (Principal Organisation).• Bamboo Australia, Belli Park, Eumundi, Queensland (Commercial grower).• Queensland DPI, Bundaberg Research Station.• NT DPIF, Coastal Plains Research Station.

68

The objectives of the project, which was approved and funded in August 1994, are:

• To identify suitable species for the production of bamboo shoots under Top Endconditions.

• To gain expertise in the cultivation of selected species and to develop culturalpractises such as irrigation and fertiliser scheduling for optimum shoot production.

• To release trial quantities of fresh product to assess its market potential.• To collate and extend information on species performance.

There is, effectively, no production of bamboo shoots within Australia. Cannedbamboo shoots are currently imported from SE Asia with a retail price between $3.00and $6.00 per kg and an estimated Australian consumption of 1, 357, 000 kg (value$6 M) per annum. A potential export market exists for fresh shoots into Asianmarkets, particularly Japan, where they represent the largest category of importedfresh vegetables into that country (44 - 85, 000 tonnes pa.).

An irrigation and nutrition trial on bamboo (Joint RIRDC/DPIF trial) was planted onFriday 24 February 1995 with plants shipped personally by Mr Dart. The bare-rootedplants were planted directly into the field under heavy monsoon conditions and todate no losses have occurred. The bamboo species, Bambusa oldhamii, was chosenfor the trial as it was less expensive than the two other preferred speciesDendrocalamus asper and D. lattiflorus.

The trial design is a 3x3x3 factorial arrangement with a split plot design. The trialcovers approximately one hectare and contains 162 clumps or plants.

3 Irrigation levels 40, 60, 80% evaporation replacement.3 Fertiliser rates3 Replications

Data collection will include:

Number of shoots produced, size and heightDiameter of culms at the 7th node above groundLeaf and soil analyses at regular intervalsSoil moisture tensiometer and EnviroScan® monitoringPhenology of shoot production in relation to treatments and to local conditionsSide branch formation on new culmsLeaf appearance and senescence

At this stage of the trial, it is anticipated that the irrigation and nutrition treatmentswill be imposed when the plants are about 2 years of age, which will be early 1997.Current management allows irrigation inputs according to tensiometer readings whichis daily irrigation. Fertiliser applications include monthly applications of 100 g NPKand 150 g urea per clump alternatively. The growth rates of the trial plants during1995 have been very encouraging so far and the plants have remained uniform andvigorous. During the year there appeared to be no dormant stage during the cooler

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dry season conditions but shoot production increased significantly from October, withrain and higher temperatures, into the wet season.

EVALUATE BAMBOO VARIETY CONSIDERED SUITABLE FORCULINARY, WIND BREAK AND TIMBER PURPOSES


An older collection of bamboo (12 species) gathered from around the Darwin area isnow 3 years old but has only been managed well for the past 2 years.

A new collection of bamboos (19 species) which include edible, timber, windbreakand ornamental types has been established . The plants were purchased mainly withDPIF funds. This collection includes 7 plants each of D. asper and D. latiflorus.these are 2 of the preferred 3 species for edible shoot production.

EVALUATION OF THE POTENTIAL OF CENTRALIAN NATIVE SPECIESAS CUTFLOWERS

G Kenna, J Mansfield

Central Australia is renowned for its diverse range of native flora. The number andtypes of native plants which grow in this region under favourable seasonal conditionsare numerous. Much of this flora is unique to the Central Australian region and hasfoliage and flower characteristics which may make them suitable for the domestic orexport native cutflower industry.

The potential of many of these plants is yet to be evaluated. Funding from the RuralIndustry Research and Development Corporation has been obtained to conduct apreliminary investigation to assess this potential.

The first stage of the project has been to identify what research and developmentwork has been conducted and to identify those plants with potential commercial use,including the ability to grow the plants under commercial cultivated conditions. Aliterature review detailing this work was completed in February 1996 and has beendistributed to various libraries.

The second stage of the project involves the field collection of various native species,preliminary investigation of their potential as cutflower or foliage and how efficientlythey can be propagated and grown under cultivated conditions. This stage howeverhas been delayed indefinitely due to the continuing extremely dry conditions in theCentral Australian region. Rainfall in the Alice Springs area for 1996 up to the end ofJuly totalled 46mm. Many other locations in the region have had similar rainfalltotals or less. These conditions are not conducive to plant growth or flowerproduction.

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Interstate/International Visitors To Horticultural Research Establishments

• July 1995∗ Queensland Cotton Growers Association∗ Jonathon Street, David and Henry Power, mango and asparagus growers∗ Graeme & Faye Winter, Jack & Thelma Butler, stonefruit growers from

Swan Hill Vic.∗ Lt Gen Winston WL Choo, High Commissioner , Republic of Singapore∗ Tangentyere Nursery staff

• August 1995

∗ Peni Sari Palupi, Trubus reporter from Indonesia∗ Filipino delegation from Mindanao

• September 1995

∗ David Putman and Ray Lennon, Sumich Group Ltd, Perth∗ Geoff Derrick, Campbell Chemical Co, Perth∗ Robert Speirs, Rural Industries Training Advisory Board∗ Paul Connolly, New World Seeds∗ Ron Gray, banana grower from Coff’s Harbour∗ Indonesian Ministry of Agriculture delegation∗ WADA/CSIRO cotton project staff∗ David & Carol Leng, commercial horticulturists∗ Peter Hodkinson, banana developer∗ Mr Hau Junduo, Chinese Ambassador∗ Simon Field, Executive Officer, AIAS

• October 1995∗ Peter Bindan, Australian Bamboo Network∗ Paul LeFeuvre & Laurence Semesco, Gira Queensland∗ Peter Schoelfield, citrus consultant∗ Hon VAKT Ingram, High Commissioner to Cook Islands∗ Roland Holmes, Nick MacLeod & Queensland growers, QDPI∗ South African mango growers∗ Indonesian scientist from Lombok∗ Chinese visitors from Anhui∗ Rod Silburn, mangosteen grower∗ M Laughlin & N Thompson, irrigation products

• November 1995

∗ Valerie Kelly, Austrade Commissioner, Kuala Lumpur∗ Robert Kennington, Solomon Islands orchardist∗ Peter Laffrey & Keith Kroeger, irrigation representatives∗ David & Henry Power, asparagus growers

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• December 1995/January 1996∗ Eduardo Cojuangco, Filipino mango grower∗ Khalip Md Nor, Renong Mining Corp, Malaysia∗ Dr Haji Morri B Othman, Minister for Agriculture, Brunei∗ Dr Victor Moffatt, Bulgul∗ Edwin Liew & Henry Jandum, Dept of Agriculture, Sarawak

• February 1996∗ Dunford Dart, Queensland bamboo grower∗ David & Henry Power, asparagus growers∗ SS Lee Pan, investor from Commercial Pty Ltd, Singapore∗ Tom Hrncirik, Natural Resource Group, California∗ Adam Body, distributor for biological central∗ Tasmanian banana and orchid growers∗ David Leng and Paul Crofton, citrus and table grape growers∗ Michael Gregg, Rural Industries Training Board∗ Dr Vyas, Godrej Soaps∗ Michael Knight, Cyanamid∗ Alan Gallagher, Group Managing Director of Main Camp Tea Tree Oil

Group∗ Fred Von Attenstadt, WA wheat/sheep farmer∗ Dave Ingledew, Prairie Seeds, Alberta Canada

• March 1996

∗ Dr A Syarifuddin Karama, Dr Moch Fatuchri Sukah and Dr Hasnam, Senior Indonesian officials

∗ Ailin Ton Dato Ishak, MARDI∗ Dr John Milne, RIRDC bamboo collaborator

• April 1996∗ Peter & Gail Hodgekinson, banana growers∗ Westpac Manager

• May 1996∗ Rod McLaren & Tony Fitzgerald, growers from Bayer, Qld∗ Ron Gray, Australian Bamboo Growers Council

• June 1996

∗ Mike Murray, extension specialist, California∗ Bob Clements, ACIAR Director∗ HJ Yeh & TJ Koh, Taiwan Sugan Corp∗ Dr Ir M Winarno, Directorate of Horticulture∗ Peter Sisnoputrante & L Laksmi Siswoputranto, Members of Indonesian

Chamber of Commerce & Industry∗ Ir. Rianti Budhipramana, Indonesian Trubus Magazine∗ Mohamed & Leila Al El-Sherei, Egyptian Ambassador∗ Peter Haslett, citrus/almond/apricot grower∗ Ray Sampson, fertiliser representative

• June 1996 (cont.)

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∗ Paul Connerley, New World Seeds∗ Prof. Burgess, University of Sydney∗ Peter Sheppard, BARA Coordinator∗ Bob Bishop, DPIE

Organisation of Seminars, Workshops and Field Days

• July 1995∗ Displays at Alice Springs, Tennant Creek, Katherine and Darwin Shows

- Hort staff

• August 1995∗ Assisted at EnviroScan Software workshop - Yan Diczbalis

• October 1995

∗ Meat Profit Day - Alice Springs staff

• March 1996∗ KRS Farm and Garden Day - Katherine staff

• June 1996∗ Assisted at CPRS Open Day - Horticulture staff∗ Lester Burgess, Sydney University

Staff Visits

• September 1995∗ Joint study tour to Kununurra to inspect/participate in Mediterranean Fruit Fly Eradication campaign - Gavin Foord, Ted Fenner, Stuart Smith

• October 1995

∗ Visit to wholesale markets in Melbourne, Sydney and Brisbane - Margaret Landrigan

• December 1995/January 1996

∗ Visit to North Queensland re RIRDC proposals - Yan Diczbalis & TK Lim

∗ February 1996∗ Visit to Dimbulah, North Queensland to look at cashew research - Gavin

Foord

• March 1996∗ Visit to Philippines to undertake mango consulting - Yan Diczbalis,

Vinod Kulkarni, Malcolm Smith

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∗ Visit to Snake Bay to inspect progress of sweet potato project - Mike Poffley, Mark Traynor∗ Visit to Loxton, Irymple, Swan Hill and Knoxfield research

establishments to inspect research work - Geoff Kenna

Seminars/Workshops Attended/Presentations

• July 1995∗ Mango 2000 Symposium, Townsville - Niranjan Dasari, Yan Diczbalis,

Vinod Kulkarni, Margaret Landrigan∗ Irrigation Presentation, Kununurra - Yan Diczbalis

• August 1995∗ Presentation to Katherine District Farmers Association, Malcolm Smith∗ Presentation to Orchid Growers Group of NT, Mark Hoult

• September 1995∗ Assisted in Mango Picking and Packing seminar - Mike Poffley∗ Presentation to 6th ACOTANC, Lismore - Vinod Kulkarni∗ Presentation to Asian Vegetables Researchers conference, Canberra - TK

Lim

• October 1995∗ Mango Tip-borer control in Cashew seminar - Malcolm Smith, Gavin

Foord and Mark Hoult

• November 1995∗ Attendance at Mango Postharvest workshop - Horticulture staff

• December 1995∗ Presentation to industry on Mango quality in the southern markets -

Margaret Landrigan

• March 1996∗ Presentation to Industry on Tropical and Sub-Tropical fruits - Horticulture staff

• April 1996∗ Presentation to National Citrus Federation Conference - Mark Hoult∗ Attendance at National Citrus Federation Conference - Horticulture staff∗ Presentation to Mango R&D meeting - Chris Wicks, Vinod Kulkarni and

Yan Diczbalis∗ Presentation of Mango Thrip Control Field Day - Mike Poffley

• May 1996∗ Presentation to industry on Exotic Fruits - Horticulture staff∗ Presentation to industry on Mango - Horticulture staff

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• June 1996∗ Presentation to industry on Anthracnose - Mike Poffley∗ Presentation to industry on Annual Crops - Kevin Blackburn∗ Presentation to Rare Fruits Council on Asian Vegetables - TK Lim∗ Presentation to Vegetable and Banana Research and Development

Seminar - Yan Diczbalis∗ Attendance at Mango Skin Browning Workshop, Rockhampton -

Margaret Landrigan

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PublicationsAgnotes

∗ Blackburn, K. and Traynor, M. Simple Home Hydroponics. Agnote B34.

∗ Landrigan, M. Lim, TK and Poffley, M. Rambutan - Postharvest Handling. Agnote D30.

∗ Landrigan, M. Morris, S. C. and Gibb, K.S. - Relative humidity influences postharvest browning in rambutan (Nephelium lappaceum L.) Hortscience 31/3 (1996) p. 417-418.

∗ Lim, T.K. 1995. Chapters on Carambolas, Rambutans and Durians in Horticulture Australia (ed. B. Coombs) Morescope Publishing Pty Ltd.Victoria, pp. 392, 453, 443 respectively.

∗ Lim T.K. and Bowman L. 1995 - Control of sapburn on “Kensington” mangoes with postharvest chemical treatment. ASEAN Food Journal 10(2):1-7.

∗ Lim, T.K. and Chung, G.F. 1995 - Occurrence of the entomopathogen, Hirsutella versicolor Petch on Idioscopus nitidulus Wlk. the mango leafhopper in Malaysia. The Planter, Kuala Lumpur 71:207-211.

∗ Lim, TK. Poffley, M. and Bowman,L. 1995 - Grafting Fruit Trees. Agnote D34.

∗ Lim, TK. 1995 - Carambola characteristics and cultivars. Agnote D27.No. 637

∗ Lim, TK. and Diczbalis, Y. 1995 - Rambutan characteristics and cultivars. Agnote D28, No 638.

∗ Lim, TK. 1995 - Durian characteristics and cultivars. Agnote D29. No.639

∗ Lim, TK. and Diczbalis, Y. 1995 - Rambutan growing and marketing. Agnote D31. No. 662

∗ Lim, TK. 1995 - Carambola growing and marketing. Agnote D32. No. 663

∗ Lim, TK. 1995 - Durian growing and marketing. Agnote D33. No. 664.∗ Poffley, M. 1995 - Green Manure Cropping in Horticulture. Agnote

D26.∗ Poffley, M and Benson, CW. 1995 - Growing Pawpaws. Agnote D8.∗ Lim, T. K. and Luders, L. 1995 - Rambutan crop nutrient requirement

and phenology. Exotic Fruit Seminar, El Arish Queensland, 6-8 May 1995

∗ Lim, T. K. Luders, L. and Poffley, M. 1996 - Studies on Irwin fruit deformity and nubbins. Proc. Int. Conf. on Tropical Fruits,

Kuala Lumpur, Malaysia, pp. 287-298, 23-26 July 1996.

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Staff Training

• July 1995∗ Farm Chemical Safety Workshop and First Aid Course - Darwin, Alice

Springs and Katherine staff∗ Communication Course - Lana Luders

• August 1995∗ Word Computer Course - Katherine staff

• September 1995∗ Effective Presentation Workshop - Margaret Landrigan∗ Firearm Safety - Paul Albano, Peter Hopkinson and Ian Jacobson

• October 1995∗ Windows and Excel Computer Courses - Peter Hopkinson

• November 1995∗ Technical Writing Workshop - John Mansfield∗ Welding & Thermal Cutting - Peter Hopkinson and Peter Slinger

• February 1996∗ Ray Prince Public Speaking Course - John Mansfield

• April 1996∗ Understanding Adult Learning - Stuart McAlister, Gavin Foord

• May 1996∗ Mediation Course - Yan Diczbalis∗ Certificate rural Farm Skills - Ian Jacobson

• June 1996∗ Senior First Aid Course - Katherine staff∗ Windows and Intro to PC’s - Paul Albano and Peter Hopkinson

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