HRP920477A2 - Process for the preparation of novel isolate of trichoderma harzianum t-39 icidal compositions containing said isolate and use against b. cinerea and s. rotiorium - Google Patents

Description

Technical field

This is an invention from the field of technology, especially from the field of crop protection.

Defined technical problem

The technical problem to be solved by this invention is: how to provide a procedure for obtaining a new isolate of Trichoderma harzianum T-39, i.e. fungicidal compounds containing the mentioned isolate, which has a significant effect on Botrytis cinerea and Sclerotinia sclerotiorum.

State of the art

There are a number of known chemical fungicides that are widely used to control crop diseases, but Botrytis cinerea has developed resistance to common fungicides in use, such as dicarboximide fungicides and benzimidazole fungicides.

The invention deals with an antifungal compound, primarily a biological control compound, containing Trichoderma harzianum and methods of protecting plants from the pathogenic fungi Botrytis cinerea and Sclerotinia sclerotiorum using such compounds.

Gray mold, caused by Botrytis cinerea Pers, and white mold, caused by Sclerotinia sclerotiorum Lib: de Bary, represent a serious problem for many crops worldwide.

Pathogens attack many crops including grapes, vegetables and ornamental plants. Cultures are attacked when grown both outdoors and indoors. If not controlled, gray and white mold can cause pre-harvest and post-harvest losses in silos or during transport. Pathogens attack all parts of plants including flowers, fruits, leaves, roots, branches, phylloclades, bulbs or seeds.

Chemical fungicides are widely used to control diseases. However, B. cinerea has developed resistance to common fungicides in use. Among them are dicarboximide fungicides and benzimidazole fungicides. In many places, farmers have no solution to this problem for resilience, and in other places or cultures, this is exactly what is likely to happen.

Epidemics of gray and white mold are often very large when the humidity is high and the temperature is between 10°C - 25°C.

The use of opposing microorganisms in the control of pathogenic fungi in plants has been the subject of extensive research. One of the most frequently studied antagonists in relation to biological control is Trichoderma (Y. Elad et al., 1982, Can. J. Microbiol. 28: 719-725; I. Chet and R. Baker, 1981, Psychopathology 71: 286-290 ; M. N. Schroth and J. G. Hancock, 1981 Ann. Rev. Microbiology 35: 459-463; Y. Elad et al., 1981, Plant Disease 65: 675-677; Y. Elad et al., 1980, Psychopathology 70: 119- 121; I. Chet et al., 1979, in B. Srippers and W. Gams ed., "Soil Borne Plant Pathogens", Academic Press, NY, NY, Y. Hdar et al., 1971, Trans. Br. Mycol Soc. 57 (3), 363-369: Y. Elad., (1990) Phytoparasitica, 18:99-105).

Trichoderma species or strains may have different resistance to different fungal species (H. D. Wells et al., 1972, Phytopathology 62: 442-447). Such differences in resistance have been found both within and between Trichoderma species (D. K. Bell et al., 1982, Phytopathology 72: 379-382). Therefore, each isolated Trichoderma, regardless of the species, has different characteristics regarding the ability to contract plant diseases.

B.Cinerea and S. scelerotiorum are susceptible to resistance compared to other microorganisms. Spore germination and hyphae growth of these plants, pathogens and host plants can be reduced when nutrients and space are limited. Such a mechanism can be the basis for successful biological control of gray and white mold. Even more, the antagonist should survive for a long time in the same niche and simultaneously act against the pathogen.

A way to solve a technical problem

In accordance with the invention, a new antagonistic species of T. harzianum was discovered, which acts against the plant pathogens Botrytis cinerea Pers and Sclerotinia sclerotiorum. The antagonist is useful for controlling the plant diseases gray mold, which is caused by B. cinerea, and white mold, which is caused by S. scelerotiorum. T. harzianum strain T-39 (I-952) is cultivated in biologically pure culture.

T harzianum T-39 (I-952) can be applied on the plant canopy, alternating with different fungicides used to control gray mold. The new strain of T. harzianum can be grown, maintained and mixed with an agriculturally suitable carrier to produce a fungicidally active biocontrol compound that controls diseases caused by B. cinerea and S. scelerotiorum. The bioactive compound can contain basic food for microparasites, or the carrier itself can serve as a nutritional base.

In one embodiment of the present invention, the biocontrol compound may also contain a suitable and acceptable agricultural adhesive. The biocontrol agent T harzianum T-39 (I-952) reduces disease caused by B. cinerea and S. scelerotiorum by 50-70% compared to untreated control. The antagonist is capable of maintaining high populations on leaves and fruits of treated plants in greenhouses, vineyards and elsewhere. T harzianum T-39 (I-952) is able to prevent the fungi B. cinerea and S. scelerotiorum from feeding and spreading. This is precisely what gives this isolate its unique ability to suppress the disease.

The invention also deals with methods of using this biocontrol compound as a fungicide in the fight against gray mold. Effective amounts of this biocontrol compound are applied to different parts of the plant.

In one of the embodiments of this invention, there is a chemical compound that is included in the biocontrol compound. T harzianum T-39 (I-952) possesses resistance to chemical fungicides that would destroy or slow down the growth of other fungi. Resistance to such chemical antagonists allows the present invention to be used in joint chemical and biological control of B. cinerea and S. scelerotiorum. The chemical fungicide is alternately applied alone, either before or after treatment with T. harzianum T-39 (I-952).

This new antagonistic strain of the Trichodema harzianum species also actively affects the pathogenic plant fungus Botrytis cinerea. The desired layer of this antagonist was isolated from the natural microflora of the phyloplane of the cucumber fruit. Antagonistic fungi were cultivated in biologically pure form, designated as T-39 and identified according to Rifai criteria (Rifai, M., Mycol, Pap. 116). This strain, Trichoderma harzianum Rifai T-39, has been deposited at the Pasteur Institute, National Collection of Cultures of Microorganisms, Paris, France, in accordance with the provisions of the Budapest Treaty on the International Recognition of Deposits of Microorganisms for patent proceedings under catalog number I-952.

T.harzianum Rifai T-39 (I-952) and mutants derived from it can be used to control gray mold caused by B.cinerea and white mold caused by S. scerotiorum. In addition to its antagonistic ability, T.harzianum Rifai T-39 (I-952) is long-lasting in plants. It can be applied to plants alternately with fungicides that act on gray mold - examples are benomyl, carbendazim, vinclozolin, ipridione, procymidon, dichlufluanide, tebuconazole, prochloraz, fenethanil, diethefenecarb, metomeclan, chlorothalonil, and mixtures of these fungicides.

T.harzianum Rifai T-39 (I-952) has resistance to the following pesticides with which it can be applied to different pesticides with which it can be applied to different agrosystems: polyoxin D, polyoxin B, TMTD, CuSO4 5H2O, diphenylamine, folpet, tridemorph , bitertanol, dimethiirimol, triforine, dichloronit, roaniline, bupirimata, hexaconazole, myclobutanil, fenitrothion, phosethyl-Al, propiconazole, azinphos-methyl, chlorpyrifos, mancozeb, endosulfate, methomyl, tridimefon, guinomethionate, diniconazole, methidathian copper oxychloride, imazalil, oxadixyl , cymoxanil, metalaxil, triadimenol, ditalimfos, sulphur, penoconazole.

In addition to the wide spectrum of antagonism and resistance to chemical fungicides and pesticides, T.harzianum T-39 (I-952) can survive for a long time and suppress gray and white mold at temperatures from 3°C to 30°C. This additional feature makes this invention a versatile biocontrol agent for use in semi-arid as well as temperate agricultural zones, in greenhouses or outdoors, in storage or in the transport of agricultural products.

The method of application of T.harzianum T-39 (I-952) is by means of conidia, chlamydospores or hyphal segments or by a combination of the previous ones, directly on the plants. Direct application of the antagonist, however, is less effective than the application of a biocontrol compound containing T.harzianum T-39 (I-952) and an agriculturally acceptable carrier.

These biocontrol compounds can be in solid or liquid form and can contain other auxiliary agents such as emulsifiers, suspending agents, adhesive agents, etc. Solid compounds can be in the form of dust, granules or powder, while liquid compounds can be in the form aqueous or non-aqueous medium, in solutions, or suspensions of sprays or concentrates.

The amount of antagonist spores, hyphae or chlamydospores in compounds should be at least 106 cells per gram of compound. The reproduction of these spores depends on the conditions for growth within the compound or on the plants on which it is applied. Such factors as compound storage time may have an effect on growth conditions in a compound containing the appropriate nutrient base.

In certain embodiments of the present invention, the transporter may be a fully or partially nutritive axis for the antagonist. The nutrient base and carrier provide the antagonist with enough food and a suitable microenvironment, thereby facilitating its establishment and long-term microenvironment and long-term maintenance on plant organs.

In other aspects of the invention, the biocontrol compounds may also contain another pesticide or other biocontrol agent, such as an isolate of antagonistic microorganisms such as Trichoderma or another type of microorganism. For the application of biocontrol compounds on the plant, use 10-1000 grams in 10-300 ml of water for 1000m2 of crop, or 0.05%-0.05% w/w of water on agricultural products before or after harvest.

There is a very large number of host plants that will be attacked by B. cinerea and S. sclerotiorum. In this scope, this invention is effective in suppressing diseases caused by this plant pathogen and is also effective in protecting plants such as cucumber, tomato, grape, rose, strawberry, blue eggplant, bean, geranium, lettuce, carrot, etc.

The fact that the invention will be explained by the following examples should not be understood as an intention to limit the use of the invention to those examples. Rather, it is intended to show all alternatives, modifications and equivalents that exist within the scope of the invention defined in the appended claims. Therefore, the following examples will include some aspects of the invention and serve as an illustration of its practical side; with the most useful and understandable description of the procedure as well as the principles and conceptual aspects of the invention.

Example 1

The Trichoderma strain was isolated from cucumber fruit in the following way:

The fruits are mixed in water at 200 rpm. Portions of water are diluted once and 0.1 ml is placed on selective medium tin plates (Elad et al. Phytoparasitica. 1981, Vol. 9, pp. 59-67). The resulting pure strain was named T-39. Isolate T-39 was identified based on the key suggested by Rifai (Rifai, M., 1969, Mycol., Pap. 116) as Trichoderma Harzianum.

Example 2

T.harzianum T-39 (I-952) is grown on a solid medium based on starch as the main food choice and celite as a water reservoir. Growth begins with the splitting of the solid medium by Trichoderma. The mixture of all nutrients is granulated and kept under incubation in a room tempered at 25°C. During 10 days of growth, the medium is turned twice, then dried and scraped off. The final product contains 5 x 10 to 1 x 1010 colony forming units (CFU) per gram. Viability tests show that the initial dry weight of 8.5 x 109 CFU/g at room temperature, within six months, changed only slightly, to 7.5 x 109 CFU/g dry weight, and after 12 months to 7 x 108 CFU/g dry weight .

Example 3

T.harzianum T-39 (I-952) was tested in the plant (potato dextrose), supplemented with different fungicides and pesticides. Conidia germination was assessed 24 hours after inoculation. Furthermore, the mycelium is also evaluated, 24 hours after splitting, at a temperature of 20+20°C. Pesticides are grouped according to their ability to control T.harzianum T-39 (I-952) (in Tables 1 and 2).

Example 4

Conidia of Trichoderma-e spp. isolates are sprayed on different plants. Vaccination of plants treated with B. cinerea is carried out later. All preparations go through incubation in a humid chamber, at 16+20°C, in order to develop gray mold. The appearance of the disease is estimated within 5 to 10 days. The percentage of disease occurrence in different isolates of Trichoderma-e spp. is presented in Table 3. The results show that T.harzianum T-39 (I-952) is much superior compared to other isolates.

Example 5

The effect of T.harzianum T-39 (I-952) on grape gray mold was tested only in vineyards, as a combination with Iprodione, or alternately with Iprodione, at three different locations, and in accordance with the recommended program in each area. The percentage of infected beans is presented in Table 4. The results show improved disease control when using T.harzianum T-39 (I-952).

Example 6

T.harzianum T-39 (I-952) is sprayed on rose plants in commercial heated greenhouses, at a temperature of 15+30°C and naturally infected with B. cinerea and compared to the effect of a mixture of tebuconazole and dichlofluanid Active biocontrol agents are sprayed at a volume of 1000 l/ha in water. Plots of 5 x 1 m were randomly arranged in 5 replicates. Table 5 shows that T.harzianum T-39 (I-952) effectively suppresses B. cinerea root infection when applied alone or alternately with a mixture of tebuconazole and dichofluanid.

Example 7

Conidia of T.harzianum T-39 (I-952) are sprayed on cut rose flowers naturally infected with B. cinerea. The flowers are incubated in a humid chamber for six days, and then the risk of gray mold is tested. As shown in Table 6, a spray containing 107 conidia per ml is more useful for the biocontrol of rose gray mold.

Example 8

The compound T.harzianum T-39 (I-952) in a volume of 1000 l/ha is sprayed on tomatoes in the greenhouse. Plots contain 20 plants in five replicates randomly. B. cinerea, which occurs naturally, is observed on roots, leaves and fruits. Fruit symptoms were either regular mold or spots. As shown in Table 8, all symptoms of gray mold or spot. As shown in Table 8, all gray mold symptoms on tomato are controlled by T.harzianum T-39 (I-952).

Example 10

T.harzianum compound T-39 (I-952) is sprayed on strawberry fruits naturally infected with B. cinerea. Treated and untreated fruit undergo incubation in a humid chamber. Table 9 shows that T-39 successfully reduced gray mold.

Example 11

Compounds of T.harzianum T-39 (I-952) were sprayed on cucumber plants in unheated greenhouses at different locations. There were at least 10 plants in the plots, repeated 5-6 times per random sample. Gray mold appeared on the fruits and roots to a different extent depending on the conditions in specific greenhouses and the natural population of B. cinerea. T.harzianum T-39 (I-952) was sprayed alone, mixed with other fungicides, or alternated with other fungicides. Table 10 shows that compounds containing T.harzianum T-39 (I-952) significantly reduce the occurrence of the disease.

Example 12 = 13

The aim of these tests was to determine if there is any influence on the process of making wine from grapes treated with compounds containing T.harzianum T-39 (I-952). The preparation T.harzianum T-39 (I-952) was sprayed at a rate of 4 kg/ha on grapes (cv. Sauvinion Blanc) in vineyards located in Ortal (Golan Heights, northern Israel). Spraying was carried out in mid-August 1989 with a manual sprayer on two vine rows, each 20 m long. The unsprayed vine rows, separated by three rows each from the spraying, served as a control. no fungicides were sprayed on the experimental sites, however, all other treatments were carried out in accordance with the recommendations for this area. On September 1, 1989, ten samples of 10 kg of grapes each were randomly selected from the vineyard and transferred to the laboratory. Grape juice was made from each sample. After preparation, SO2 was added to the juice, and 6 hours later yeast and nutrients were added, in accordance with the recommendation. The fermented juice was incubated in one-liter bottles with a tap through which CO2 was released from the system.

The Brix level (%) was measured by a Brix meter, and the results are shown in Table 11. The yeast cell population was counted using a chemocytometer and the results are shown in Table 12. Based on these results, it can be concluded that the total soluble solid mass from the control and from grapes treated with T-39, measured by the Brix method, does not differentiate. Even more, while the initial measurements showed a drop in the yeast cell population, this was not statistically significant and after 8 days the results were basically the same. Therefore, the use of T.harzianum T-39 (I-952) on grapes does not have any significant effect on ethanol production. Finally, the taste of the wine showed no difference in taste, color, aroma and clarity compared to the wine whose grapes were treated with T.harzianum T-39 (I-952).

Example 14

Conidia of T.harzianum T-39 (I-952) were sprayed on rose flowers. The flowers were then, within one week after spraying, monitored for T. harzianum population levels on them. The level of the T. hatzianum population was determined by washing the flowers in water containing 0.001 M Tween-20 series of water solution and placing them on the selective medium of Trichoderma. Colonies were counted after incubation for 5 days at a temperature of 20°C. The population level of T. harzianum did not drop drastically during that week, as we can see from Table 13.

Example 15

The T.harzianum compound T-39 (I-952) was sprayed on the strawberry plant in plots (4 replicates of 10 x 1.6 m) placed in random blocks, at a rate of 0.2% to 0.4%, so the results were compared with the effect on chemical fungicides. After four weeks, the disease on strawberries was reduced by the use of T.harzianum T-39 (I-952) at a rate similar to that of fungicides, according to Table 14.

Example 16

The compound T.harzianum T-39 (I-952) is applied at a rate of 0.2% to 0.4% to S. sclerotirum naturally infected carrots. Carrots were treated after harvest and underwent a period of incubation in a humid chamber. After two weeks, the degree of white mold disease was examined. It can be seen that white mold on carrots is significantly reduced due to T-39; but was not reduced by thiobendazole applied at the recommended ratio, as shown in Table 15.

Example 17

The compound T.harzianum T-39 (I-952) was sprayed on the cucumber plant in the greenhouse. T-39 population was measured on leaves and fruit as factors of time. In Table 16, it can be seen that the biocontrol agent settled on the cucumber plant.

TABLE 1

Susceptibility of T.harzianum T-39 (I-952) to PDA pesticides

Highly inhibiting agents Artificially inhibiting agents

Vinclozolin NPC

Iprodione Polyoxin D

Carbendazim Polyoxin B

Benomyl Dicflofluamid

Chlorothalonil Thirane

Methomeclane CuSO4; 5H2O

Phenethanyl Diphenylamine

Fluazinon Folpet

Tebuconazole Bitertanol

Prochloraz

a = prevention of pesticide concentrations of 2 ppm or less

b = prevention of pesticide concentration 2 - 15 ppm

TABLE 2

Susceptibility of T.harzianum T-39 (I-952) to PDA pesticides

Without preventing*

Dimethirimol

Triforim

Dichloronitroanilines

Bupirimate

Hexaconazole

Myclobutanil

Fenitrothion

a = prevention of pesticide concentrations of more than 15 ppm

TABLE 3

Severity of gray mold disease in the presence of Trichoderma spp. Isolates were applied as conidial suspensions.

Isolates Origin Tomato Pepper Geranium Rose

control 100 100 100 100

T-39 cucumber 61 46 6 20

T-44 country 83 80 126 25

TOM country 83 56 111 40

T-502 country 67 56 111 25

T-672 country 100 53 36 58

T-35 country 100 80 44 50

T-Y country 100 60 36 57

T-164 G cucumber 100 80 92 40

T-180 H country 100 60 180 50

T-80 country 100 73 180 65

T-RCTI grapes/France 78 80 17 65

T-28 country 67 66 55 65

T-65 G blue eggplant 122 66 64 83

T-315 country 133 66 100 83

T-FOR country 89 80 100 58

T-94 country 100 56 111 75

T-501 country 66 93 83 25

T-132 G tomato 100 73 110 40

T-CWIO country 89 100 72 83

T-GAM country 100 68 127 108

T-GEN-12 country 88 80 154 100

T-33 country 96 86 50 100

T-177 G cucumber 100 86 62 60

T-55 country 100 86 100 200

T-199 G grapes 100 100 100 163

T-596 grapes 100 73 100 125

T-133 G grapes 68 73 130 100

T-191 G tomato 100 75 72 100

T-192 G blue eggplant 100 80 50 63

a = greenhouse

TABLE 4

Effect of T. harzianum T-39 (952) and iprodione on gray mold in grapevine.

[image]

a = gram of active ingredient per hectare

b = 4 kg/ha formulation

c = A = precipitation drops; B = Shrub clos; C = Verarion; D = before harvest

d = 22 days after treatment 3

e = 10 days after treatment 4

f = 14 days after treatment 4

g = 4 days after treatment 4

h = 21 days after treatment 4

Location Dates of treatment

Cascasomne 1989 21.06.89. 07.05.89. 17.08.89 11.09.89.

Chazay d'Azerguer 1989. 14.06.89. 04.07.89. 03.08.89. 22.08.89.

Villefranche 1989. 15.06.89. 04.07.89 01.08.89. 21.08.89.

TABLE 5

The effect of T. harzianum T-39 (I-952) on gray mold on the roots of rose bushes.

Treatment Cumulative roots Number of infected plants

Untreated control 10.8

T-39 (I-952) 5,6

Terbuconazole + Dichlofluanide T-39

before Tebuconazole + Dichlofluanide 3.8 3.8

Polyoxin B (1.0 g/1) 3.8

TABLE 6

Effect of conidia of T. harzianum T-39 (I-952) sprayed on rose flowers naturally populated with

B. Cinerea.

Conidia concentration (per ml) Disease index

0 2.7

106 2.0

107 1.0

a = after 6+ days in humid chamber

b = key: 0 = No disease

5 = fully infected

TABLE 7

Effect of T. harzianum T-39 (I-952) sprayed in acid on gray mold of grapes.

Treatment of infection on 10 vines

CV. CV. Shami a, b Cu. Shami a, c

Untreated control 6.2 20.3 5.6

T-39 (4 g/l) 2.8 13.3 2.7

Folpet 1.8

Iprodione (0.5 g/l) 8.6 2.3

Diethofencarb + Carbedazim (0.25 g/l each) 11.3 0.3

T-39 + Iprodione 3.0 1.3

T-39 replaced by Diethocarb mixture

and Carbedazim 11.0 3.0

a = grape cultivar

b = tested in the vineyard

c = tested 7 days after harvest

TABLE 8

Effect of T. harzianum T-39 (I-952) on tomato plant in greenhouse.

Treatment Rotting Infected Infected Stain

fruit, leaves, roots, on fruit

Untreated control 39.8 20.4 1.2 2.6

T-39 (4 g/l) 23.8 13.0 0.2 0.5

Iprodione (0.5 g/l) 15.0 4.6 0.2 0.3

a = number of infections on 10 plants

b = disease index

0 = healthy fruit

5 = fruit completely covered with spots

TABLE 9

Effect of T. harzianum T-39 (I-952) on post-harvest control of gray mold in strawberry.

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[image]

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a = Disease Index:

0 = healthy

5 = Completely destroyed

TABLE 10

Effect of T. harzianum T-39 (I-952) on fruit and root infections of cucumbers at different locations in Israel.

Disease cases as the number of infections per 10 plants

Treatment Arab Herutb Gadishb Intanb Ahitub

Fruit Root Fruit Fruit Root Fruit Root Root

Netret. Control

Vinclozolin (0.5 g/l) 18.3 4.3 - - - - - -

Iprodione (0.5 g/l) - - 88.0 5.5 4.8 13.4 16.8 1.5

T-39 (2 g/l) 10.8 2.0 - - - - - -

T-39 (4 g/l) - - 14.1 3.8 5.5 15.0 24.0 2.0

T-39 (4 g/l) mixed

with Iprodione (0.5 g/l) - - 15.0 2.8 1.5 15.4 15.3 0.2

T-39 (4 g/l) alternately

with Iprodione (0.5 g/l) - - - - - 12.5 22.0 -

a = sprayed at a volume of 1000 l/ha

b = location in Israel

TABLE 11

Effect of T. harzianum T-39 (I-952) on the brix level of grape juice made from grapes treated with T-39.

Treatment in the vineyard Days of incubation

1 3 8 11 17

Control 16.0 11.8 6.4 6.3 6.3

Trichoderma T-39 (I-952) 15.5 11.1 6.2 6.2 6.2

Differences between treatments of the indicated dates are not statistically significant, according to Duncan's multiple range test (P = 0.05).

TABLE 12

Effect of T. harzianum T-39 (I-952) on the high number of yeast sites in grape juice made from grapes treated with T-39.

Treatment in the vineyard Number of yeast cells (x 104)

Days of incubation

1 3 8 11 17

Control 9280 12520 6000 17.8 38.2

T. harzanium-a T-39 (I-952) 6960 10300 1802 90.9 47.7

Differences between treatments on the indicated days were not statistically significant, according to Duncan's multiple range test (P = 0/05).

TABLE 13

Population of T. harzianum T-39 (I-952) on rose flowers treated with conidia of the bicontrol agent

Initial population level

Days of incubation 0 1 2 3

1 0 9.0 x 105 2.7 x 107 1.6 x 10a

3 0 5.2 x 10a 2.3 x 107 4.0 x 10a

7 0 2.0 x 10a 0.3 x 107 0.8 x 10a

TABLE 14

The effect of T. harzianum T-39 (I-952) on strawberry gray mold in a naturally infected field

Treatment Infected fruit/rows of 10 m

Control 11.25

T-39 (0.2%) 6.75

T-39 (0.4%) 4.50

Folpet (0.25%) 4.0

Carbendazine + Dithiofencarb (0.1%) 3.75

A = Spraying done four weeks before disease assessment

TABLE 15

The effect of T. harzianum T-39 (I-952) on S. sclerotiorum applied to carrots after picking

Treatment Disease index a, b

Control 0.714

T-39 (0.2%) 0.536

T-39 (0.4%) 0.427

Thiabendazole (0.1%) 0.821

a = Two weeks after treatment

b = Key

0 = No disease

5 = Completely destroyed carrot

TABLE 16

Population level of T. harzianum T-39 (I-952) on cucumber leaves and fruits in the greenhouse

Propagules of T harzianum

Time (Days after application) Per leaf Per fruit

Untreated Treated Untreated Treated

0 54 20 0 0

28 232 9000 210 300

21 2300 450000 1500 350000

Claims (24)

1. Biologically pure stable culture of Trichoderma harzianum indicated by the fact that it has the physical characteristics of Trichoderma harzianum Rifai T-39 (Institut Pasteur Deposit No. I-952) or that it is a mutant derived from it that retains the bioinhibition properties of the parent strain. 2. The culture according to claim 1, characterized in that it is additionally resistant to an amount of a chemical antagonist capable of significantly retarding growth or killing fungi or pests. 3. Culture according to claim 2, characterized in that the chemical antagonist is a pesticide. 4. Culture according to claim 3, characterized in that the pesticide is a fungicide. 5. Culture according to claim 4, characterized in that the fungicide is selected from the group consisting of folpet and dicarboximide fungicides. 6. Culture according to claim 5, characterized in that the dicarboximide fungicides are selected from the group containing iprodiones and vinclozolin. 7. Biocontrolling compound characterized by the fact that it contains an effective amount of a culture of a biologically pure stable culture of the Trichoderma harzianum strain, designated as Trichoderma harzianum Rifai T-39 (Institut Pasteur Deposit No. I-952) or that it is a mutant derived from it that retains the bioinhibition properties of the parent soybean and a suitable agronomically acceptable carrier or diluent. 8. Biocontrol compound according to claim 7, characterized in that the concentration of the antagonist contained in the culture is at least 105 cells per gram of the compound. 9. Biocontrol compound according to claims 7 or 8, characterized in that the antagonist contained in the culture is present in the form of conidia, hyamidospores or hyphal fragments, or a mixture of these types of cells. 10. A biocontrol compound according to any one of claims 7 to 9, characterized in that the carrier includes a nutrient medium for the antagonist contained in the culture. 11. A biocontrol compound according to any one of claims 7 to 10, characterized in that it also contains a chemical pesticide. 12. The biocontrol compound according to claim 11, characterized in that the chemical pesticide is a fungicide. 13. The biocontrol compound according to claim 12, characterized in that the chemical fungicide is selected from the group consisting of folpet and dicarboximide fungicides. 14. Biocontrol compound according to claim 13, characterized in that the dicarboximide fungicides are selected from the group containing iprodione and vinclozolin. 15. Method for controlling the growth of unwanted fungi on plants or crops, indicated by the fact that a compound containing an agricultural carrier and a fungicide effective amount of a biologically pure stable culture of the Trichoderma harzianum Rifai T-39 strain is applied to the plant or crop (Institut Pasteur Deposit no. I-952) or a mutant derived from it that retains the bioinhibition properties of the parent strain, useful as a biocontrol agent. 16. The method according to claim 15, characterized in that the unwanted fungus is Botrytis cinerea. 17. The method according to claim 15, characterized in that the unwanted fungus is Sclerotinia scleretiorum. 18. The method according to any one of claims 15 to 17, characterized in that the concentration of the antagonist contained in the culture is at least 105 cells per gram of compound. 19. The method according to any one of claims 15 to 18, characterized in that the antagonist contained in the culture is present in the form of conidia, hyamidospores or hyphal fragments, or a mixture of these cell types. 20. The method according to any one of claims 15 to 18, characterized in that the carrier includes a nutrient medium for the antagonist contained in the culture. 21. The method according to any one of claims 15 to 20, characterized in that the compound also contains a chemical pesticide. 22. The method according to claim 21, characterized in that the chemical pesticide is a fungicide. 23. The method according to claim 22, characterized in that the chemical fungicide is selected from the group consisting of folpet and dicarboximide fungicides. 24. The method according to claim 23, characterized in that the dicarboximide fungicides are selected from the group containing iprodione and vinclozolin.