plant growth promoters

7/28/2019 Plant Growth Promoters

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There are many pro-

ducts on the marketwhich form a conne-cting link betweenoliar fertilizers and

pesticides. Are theyeffective?

Plant growth promoters…they do work!

At numerous requests of our readers, the edi-torial staff of “top agrar Poland” undertook another difficult task, which is a test of plantgrowth promoters. Under this general namestand products named by their manufacturersand distributors in many different ways: bio-stimulants, growth stimulators, nutrient acti-vators, promoters etc. In fact these marketingnames introduce only confusion to the mar-ket and do not help the farmers to understandthis type of product. Manufacturers are trying

to be different from each other by describingtheir products in more and more sophisticated

ways. It is worth noting that plant growth promoters can be registered and introducedto market in many different ways and fromthis comes the variety of their descriptions.Some of these products are registered as pe-sticides (Asahi), others as foliar feeds or bio-stimulant fertilizers. Nevertheless farmers aredemanding to be able to categorise this groupof products and most of all, to verify their effectiveness.

Different registration procedures

If a manufacturer decides to register his pro-duct as a plant protection product, he has theright to say on the label that it regulates pro-cesses in plant in a different way than fertili-zer materials (e.g. it is a growth regulator or stimulator of growth and yield). However, itinvolves very high costs of registration, seve-ral hundred times higher than in a case of re-gistering product as for example a fertilizer.This procedure was used for example in thecase of Asahi and the Kelpak product (due

to the change in legislation Kelpak is notanymore in the register of pesticides).Because of that these products have beentested not only in terms of chemical compo-sition, but also their effectiveness (the testingserved to prove that the product works, as itis specified on the label) .Plant growth promoters can be also regis-tered as biostimulants, according to the pro-cedures used in the registration of fertilizers.Therefore these products need to be additio-nally amended with nutrients in the form of macro or microelement salts. If there wereno nutrients, it would be impossible to regi-ster them in this way. During the registration

procedure manufacturer receives a WE sym- bol, which indirectly confirms that the pro-duct complies with EU regulations. That iswhy these products are described as fertili-zers on the official labels and informationabout additional ingredients (extracts of algae, amino acids, plant extracts and recen-tly also yeast extracts) that are also compo-

nents of these products, may be used as amarketing trick or the information remainssecret known only to the manufacturer.

Simply, these products must be introducedon the market as fertilizers, because theyunderwent this type of official registration.

Tomasz Czubiński

Spring barley, in which plant growth promoters were tested, was exposed to stressfactors: severe frosts after emergence and drought at the tillering stage.



One of the components of many plant growth promoters is an extract from sea algae. Producers of such products

indicate different origin of the algae.

1

Asahi SL

(is registeredaccording tothe proceduresof plant protectionproducts, however not in cereals)

Mode of action in plant according to manufacturer (distributor)

Composition (active ingredients) Manufacturer (distributor)

Products

C-Weed 50 R

Forthial

ProPlex

Nutri-PhitePGA

PRP EBV

Growth regulator and yield stimulant, accelerating lushplant growth, prolonging the fruiting periodand contributing to higher yield and improved qualityof yield. It is advised to apply in the event of crop damagewith e. g. plant protection products or in the stressconditions such as drought, frost and after sawing

Sodium p-nitroPhenolate - 0.3%Sodium o-nitrophenolate - 0.2%Sodium 5-nitroguaiacolat e- 0.1%

(compounds from the group of nitrophenolsparticipate in important metabolic processes)

Arysta

LifeScience

Poland

Product for foliar application accelerating plant developmentand increasing tolerance to stress.

Low-temperature concentrate of sea algae collectedin Atlantic ocean and manganese (Mn) - 3%

Agro-Sieć

Activator of yield, optimizing nutrition and increasingphotosynthetic activity of flag leaf and F-1 leaf- producers

of assimilates for ear, increasing yield and improvinggrain quality

PAT (Physio Activator Technology - a patentedtechnology based on extracts

from seaweed - Ascophyllum nodosum);nitrogen- 6,2%, magnesium - 9%

Arysta

LifeScience

Poland

Daslgety Agra

Poland

Phosphite biostimulant causing more effective usage of nitrogen and according to the manufacture containingthe fastest acting phosphorus

Nutrients, including 26% of phosphorus as phosphitewith amino acid

Promoter of plant growth and development, acceleratingthe growth and increasing crop tolerance to stress

seaweed concentrate (5%) and nutrients:total nitrogen-2%, magnesium - 0.3%,sulphur - 5%,boron - 0.15%,copper - 0.05%,iron - 0.2% ;manganese - 0.1%,zinc - 0.5%,and trace amounts of plant hormones,betaine, amino acids, vitamin B1

AgraTechnologiePrzyszłości

Physiostimulant of plant vital functions, activating the naturalplant response mechanisms to stress, allowing the useof genetic yield potential, a concentrated solution of mineralsfor foliar application

potassium (K2O) - 3.5%,magnesium (MgO) - 0.42%copper (Cu) - 0.02%,and sulphur, manganese, boron and sodium

PRP Technologies

Characteristic of tested plant growth promoters

Regulating the legal status

It depends on the manufacturers if they will conceal a chemical compo-sition of the products or place somelimited information on the labels (if the products are not registered as pes-ticides). At the moment farmers donot trust such descriptions and would

prefer it was stated clearly what theyuse and what, in case of any doubts,they can analyse for. Arable farmersare spending often more than $15/hafor these products and they are skep-tical about the “magic” effects claimed

by the manufacturers, and would liketo have reliable information about the

product content and confirmation aboutit effectiveness. Hopefully in the nextfew years the situation of the legalstatus will be standardized. The Euro-

pean Biostimulants Industry Consor-tium, brings together a variety of ma-nufacturers of such products and cla-ims to establish legal directives for registration procedures of these pro-ducts, was formed. Remi Lacaille fromArysta LifeScience company who isa representative of the Consortiumclaims that the registration procedure

of biostimulants should be developed.It should not be as strict as in the caseof plant protection products becausethese products are based on naturalextracts. If there will be no need for toxicological and ecological examina-

tions (as it is the case of pesticides),the registration procedure will be cheaper.The Consortium, however, is supportingtesting the efficacy of these products infield conditions. We will have to wait for the results of the activity of European



Biostimulants Industry Consortium.Being aware of the fact that the develop-ment of European law is rather slow,

this will probably take several years. Nevertheless it is definitely worth sup- porting such an initiative, which willhelp clarify the situation of plant growth

promoters on the market, at least thoseof natural origin. For the time beinghowever, when we buy these productswe must rely on the label, informationabout the efficacy of such products,which are in most of the cases testedonly by their manufacturers or now…our studies conducted in “top agrar Poland”.

During the production of algae-based products, a macerate (cream) is obtained as first and then it is filtered to remove the solid parts

Experiment in difficult conditions

The experiment was carried out in thefields of the Experimental StationIUNG - PIB in Baborówek, near Sza-motuły (Great Poland province) under the supervision of Dr. Edwin Naglik and Dr. Krzysztof Kubsik. Spring 2011was very tough for barley over there.In the first few days of May, a monthafter sowing the barley, a heavy frost

occurred. The ground temperaturedropped to -11 ° C. From mid-May,when barley entered in the critical phase in terms of water supply, therewas a drought that lasted over a month.These were extremely stressful condi-tions for barley, which negatively affe-cted the yield throughout the wholespring barley crop. Harvested field of spring barley was just over 2.5 t / ha,which was the lowest result for manyyears.

Results of our experiment

We tested the effectiveness of plantgrowth promoters in the conditions as

described above. These conditionsseem to be ideal for testing the effecti-veness of anti-stress products (table 1).

However, when a short-term stressturns into lethal stress, there is nothingthat can be done to prevent it. The effe-ctiveness of plant growth promoterswas tested in replicated large areaexperiments (each product was appliedto a total field of area of 1 ha , in adose and the timing according to thelabel or the experts’ recommendationsfrom the manufacturers). Although thisexperiment meets all the criteria of ascientific study, it must be emphasizedthat it is a one-year study, based on onevariety of barley. Drawing conclusionsabout the economic comparison of pro-ducts will be possible when the experi-ment will be repeated using manydifferent varieties of barley, in differentyears and locations. This might be agreat opportunity for independentscientific bodies. Shortly after the first

stress factor, frost in May, Asahi SL,Asahi SL in mixture with Forthial,slightly later ProPlex and C-Weed 50 R

were applied. At the latest, Nutri-PhitePGA and PRP EBV were applied. Thelast two products did not affect the low-temperature stress in May, but onlyassisted the plant in overcoming theJune drought. Two factors were evalu-ated during the barley growing season(table 3): twice the vigour of plants(in the watery ripe phase at BBCH 71and at early dough stage; BBCH 83)and the infection by fungal diseasesunder the supervision of Prof. Marek Korbas and Tadeusz Ławecki. Exami-nation of the foliar disease situationaimed to investigate whether these pro-ducts in any way can increase the plantresistance to diseases (as it is frequentlyclaimed by promoters’ distributors intheir marketing materials). Despite the

poor condition of barley that was origi-nally affected by the May frost (in terms

BBCH 71 BBCH 83 of infection of infrction % of infectionin comparisonto control

Control 3 2 0.9 3.5 100

Asahi SL 3,5 2 0.8 2.8 80

Asahi SL+ Forthial 3,5 3 0.4 2.4 69

Forthial 3 2.5 0.7 2.6 74

Nutri–Phite PGA (2×) 3 3 0.6 2.9 83

ProPlex 4 3.5 0.4 2.4 69

PRP EBV (2×) 3,5 3 0.5 2.6 74

C–Weed 50 R 4 3.5 0.4 2.6 74

CombinationsPlants’ vigor* Net blotch**

* Rank of plant greenness in 9 scale (where 0 - yellowish leaves, plants’ drying up, 9 - plants vividly green).**First examination: BBCH 71 (13.06.2011)- leaf F-1 and F-2 examined. Secondexamination: BBCH 83 (30.06.2011)- trace occurrence of powdery mildew, rust in controls(0.1% of infected leaves in each)

o o o

BBCH 71 BBCH 83

Evaluation of the leaves’ health condition*

*Dates of treatments: BBCH 22 – 09.05.2011 (when the frost has finished),BBCH 23 – 13.05.2011, BBCH 30 – 16.05.2011, BBCH 47 –31.05.2011

Scheme of the use of plant growth promoters

Combinations Dose (l/ha) Growth stages *

Asahi SL 0.6 BBCH 22

Asahi SL + Forthial 0.6 + 1.0 BBCH 22

Forthial 1.0 BBCH 47

Nutri-Phite PGA 0.5 BBCH 30

0.5 BBCH 47

ProPlex 1.5 BBCH 23

PRP EBV 2.0 BBCH 30

2.0 BBCH 47

C–Weed 50 R 0.75 BBCH 23



Tested barley was checked mainly for net blotch, powdery mildew and rust occurrence. The health condition of barley plants was examined in laboratory conditionsby Prof. Marek Korbas from IOR in Poznań, Poland.

of density) and the poorly filled ears(due to prolonged drought) it can beconcluded, based on the conductedexperiments, that all the tested pro-

ducts were effective. We noted as wellthat products that were applied later maintain a better vigour through toharvest. Severe drought and low plant

population did not favour the diseaseoccurrence. However even this para-meter was evaluated. The intensifica-tion of only one disease, net blotch,was noticed on the spring barley. Notuntil the end of vegetative growth,after the rainfall, were powdery mil-dew and rust observed. With so little

infection by pathogenic fungi (only 3.5 percent of the controls were infectedwith net blotch at the beginning of early dough stage), it was concludedthat all the products, even though notfungicides themselves, they measura-

bly reduced the infection rate by pathogenic fungi. Although this"effectiveness" is not high, surprisin-gly positive is the fact that it contribu-tes to the health condition of barley

plants. This confirms that probably

these products increase the resistancein crops.

Yield of barley has increased

At the end of growing season eachtested field (large area experiment,fields of area of around 1 ha) washarvested using a combine harvester with isotopic yield sensor and GPS.All of the products’ combinations usedin the experiment had a positive in-fluence on the barley yield (table 4) anincrease in yield from 0.3 to 2.1 dt /hawas observed. Nevertheless, we shouldnot be comparing here individual pro-

ducts. In extremely difficult conditionsthe obtained yield is not the final indi-cator of the economic effectiveness of the product. If we compare the percentof yield increase and the thousandgrain weight increase, we can makeconclusions about the effectiveness of such products, especially in stress con-ditions. With such a low yield of barleywe can not draw a direct conclusionabout the economic response (if thetotal input was paid back with the yield

increase?). Although we did not ma-nage to fully answer which productis the best, this study helped clarifydoubts about the efficacy of this type

of product. Now we can say for surethat they work positively under thestress conditions. In addition, further trials on larger areas should be under-taken in the future.

Tomasz Czubiński

Yield, thousand grain weight (TGW) and the cost of plant growth promoters’ use

*Yield increase in comparison with the control. **Selling prize of barley 80zł/dt.

Combinations Yield Increase in yield and TGW* Income

growth per ha

(zł/ha)**

(zł/ha)

dt/ha dt/ha % TGW %

Control 24.6 - - 44.0 - - -

Asahi SL 25.0 0.4 1.6 44.6 1.4 32.0 60.0

Asahi SL + Forthial 26.0 1.4 5.7 44.9 2.1 112.0 100.0

Forthial 25.1 0.5 2.0 44.4 0.9 40.0 40.0

Nutri-Phite PGA (2x) 24.9 0.3 1.2 44.5 1.1 24.0 72.0

ProPlex 26.7 2.1 8.5 45.2 1.4 168.0 42.0

PRP EBV(2x) 25.5 0.9 3.7 44.6 2.7 72.0 188.0

C–Weed 50 R 27.0 2.4 9.8 44.6 1.4 192.0 60.0

Costs of treatments

plant growth promoters

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