METHOD FOR PREVENTIVE TREATMENT OF A CROP PLANT TO LIMIT THE LOSS OF DRY MATTER DUE TO ABIOTIC AND/OR BIOTIC STRESS

Abstract

The invention relates to a method of preventive treatment of a cultivated plant to limit the loss of dry matter linked to abiotic and/or biotic stress, consisting of applying to the plant, before the appearance of said abiotic and/or biotic stress, a slurry comprising: water; and a base, said base comprising at least one surfactant and a mixture of phytosterols comprising β-sitosterol.

Claims

1. A method of preventive treatment of a cultivated plant to limit the loss of dry matter linked to abiotic stress, consisting of applying to the plant, before the appearance of said abiotic stress, a slurry comprising: water; and a base comprising at least one surfactant and a mixture of phytosterols comprising β-sitosterol.

2. The method according to claim 1, characterized in that the abiotic stress is water stress.

3. The method according to claim 1, characterized in that the abiotic stress is heat stress.

4. The method according to claim 1, characterized in that the β-sitosterol represents at least 30% by mass of the slurry of phytosterols and in that the mass ratio of the phytosterols/surfactants mixture comprises between 0.01 and 5; advantageously between 0.1 and 2.5.

5. A method of preventive treatment of a cultivated plant to limit the loss of dry matter linked to biotic stress, consisting of applying, before the appearance of said biotic stress, a slurry comprising: water; and a base comprising at least one surfactant; and a mixture of phytosterols comprising at least 30% by mass of the mixture of β-sitosterol; wherein the mass ratio of the mixture of phytosterols/surfactant being between 0.01 and 5; advantageously between 0.1 and 2.5.

6. The method according to claim 5, characterized in that the biotic stress results from a fungal, bacterial, viral infection, pest damage and/or competition with weeds.

7. The method according to claim 1, characterized in that the application of the slurry is by foliar spraying and/or irrigation and/or soaking of the seed.

8. The method according to claim 1, characterized in that the cultivated plant is a chlorophyll plant, advantageously selected from the group comprising the plants of large crops of cereals, oilseeds and protein crops; viticulture; roots and tubers; horticulture; sod; vegetable gardens; aromatics and spices; arboriculture or industrial cultivation of plants intended for the production of a raw material with a view to its transformation.

9. The method according to claim 1, characterized in that the cultivated plant is selected from the group comprising soybeans, corn, barley, millet, Hungarian grass, miscanthus, panicum, sorghum, peanuts, wheat, rapeseed, sunflower, protein peas, field peas, field beans, lupine, flax, truncated alfalfa, grapes, beets, potatoes, beans, lettuce, parsley, rice, radishes, fruit trees and ornamental plants.

10. The method according to claim 4, characterized in that the 100% supplement to the phytosterol mixture optionally comprises campesterol, stigmasterol and brassicasterol.

11. The method according to claim 1, characterized in that the at least one surfactant is selected from the group comprising anionic surfactants, advantageously those whose polar head is a carboxylate, a sulfonate or a sulfated alcohol; cationic surfactants, advantageously those whose polar head is an amine, a quaternary amine or a quaternary ammonium ester; amphoteric surfactants, advantageously betaine or phospholipid derivatives; and neutral surfactants, advantageously ethoxylates, alkanolamines, alkylglucamides, polyol esters, alkyl-mono and alkyl-poly-polyglucosides or polyol ethers; natural surfactants, advantageously soy lecithin or surfactants derived from amino acids; and/or surfactants synthesized from natural raw materials, advantageously polyol derivatives, preferably sugar and fatty acid esters; preferably, the sugar and fatty acid esters are sucrose stearate, sucrose palmitate and their polyesters.

12. The method according to claim 1, characterized in that: the mixture of phytosterols further comprises campesterol, stigmasterol and brassicasterol; and the at least one surfactant comprises sucrose stearate, advantageously a mixture comprising sucrose stearate and sucrose palmitate.

13. The method according to claim 1, characterized in that the slurry is applied by foliar spraying at a rate of 0.1 L/ha to 15 L/ha, advantageously at a rate of 1 L/ha to 5 L/ha.

14. A slurry implemented by the method according to claim 1, characterized in that it comprises: water; and a base comprising at least one surfactant and a mixture of phytosterols comprising β-sitosterol.

15. The slurry according to claim 14, characterized in that the base represents between 1 ppm and 20% by mass of said slurry, advantageously between 1 ppm and 10%, the complement to 100% being water or a mixture comprising water and one or more active ingredients.

16. A base for the manufacture of the slurry according to claim 14 in the form of an oil-in-water emulsion the particle size of which is less than 500 μm comprising: an aqueous phase representing between 60% and 95% by mass of the base; an oily phase representing between 5% and 40% by mass of the base comprising: at least one surfactant; and a mixture of phytosterols comprising β-sitosterol, wherein the mass ratio of the phytosterol/surfactant mixture being between 0.01 and 5, advantageously between 0.1 and 2.5.

17. The base according to claim 16, characterized in that the phytosterol mixture represents between 0.5% and 10% by mass of the base, advantageously between 0.5% and 7%, preferably between 1% and 5%.

18. The base according to claim 16, characterized in that the surfactant represents between 0.2% and 30% by mass of the base, advantageously between 1% and 20%, preferably between 2.5% and 15%.

19. The base according to claim 16, characterized in that the surfactant is a mixture comprising: between 20% and 80% by mass of the surfactant, advantageously 70%, of sucrose stearate, the monoester content of which is between 20% and 80% by mass of the sucrose stearate, advantageously 70%, the remainder being a mixture of di-, tri- and/or polyesters; and/or between 20% and 80% by mass of the surfactant, advantageously 30%, of sucrose stearate, the monoester content of which is between 20% and 80% by mass of the sucrose stearate, advantageously 30%, the remainder being a mixture of di-, tri- and/or polyesters.

20. The base according to claim 16, characterized in that it further comprises at least one component selected from the group comprising: at least one fluidifying agent chosen from the group comprising a polyethylene glycol with an average molecular weight of between 200 and 8000 Da, advantageously between 200 and 1000 Da, preferably 400 Da; the fluidifying agent advantageously represents between 1% and 15% by mass of the base, advantageously between 2% and 8%; at least one phytosterol solubilizer agent selected from the group comprising oleic alcohol; oleic acid; linoleic acid and a vegetable oil, advantageously soybean oil, sea buckthorn oil, corn oil, rapeseed oil, sunflower oil; the solubilizing agent advantageously represents between 2 and 30% by mass of the base, advantageously between 4 and 15%; at least one wetting agent selected from the group comprising a mixture of methyl esters advantageously comprising methyltetradecanoate, methyloctadecanoate and methylhexadecanoate, the wetting agent advantageously represents between 0.1% and 5% by mass of the base; at least one chelating agent, selected from the group comprising natural chelating agents, advantageously sodium phytate or chelating agents based on amino acids; and synthetic chelating agents, advantageously 2,2′-bipyridine, dimercaptopropanol, ethylene glycol-bis-(2-aminoethyl)-N,N,N′,N′-tetraacetic acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, salicylic acid or also triethanolamine, preferably EDTA; the chelating agent advantageously represents between 0.01% and 5% by mass of the base; and/or at least one preservative selected from the group consisting of benzyl alcohol, benzoic acid, dehydroacetic acid, salicylic acid, sorbic acid and one of their salts, advantageously benzyl alcohol; the preservative advantageously represents between 0.1% and 5% by mass of the base.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0138] FIG. 1 shows the raw data of the evolution of the water resistance (W/R) of the soil over 24 hours of a soybean crop treated with the slurry according to the invention (base diluted to 3% by mass in water) relative to a control soybean crop and the wilting point.

[0139] FIG. 2 shows the average values of the water resistance (W/R) of the soil, measured over 24 rolling hours of a soybean crop treated with the slurry according to the invention (base diluted to 3% by mass in water) relative to a control soybean crop.

[0140] FIG. 3 represents the effect of the use of the slurry according to the invention as a pre-germination treatment on the germination of sorghum seeds: percentage of germinated seeds treated (control with water, or in a slurry comprising the base according to the invention diluted to 3% by mass) based on time (days).

[0141] FIG. 4 represents the effect of the use of the slurry according to the invention as a pre-germination treatment on the radicle growth of sorghum seeds: mean size of the radicle (control with water, or in a slurry comprising the base according to the invention diluted to 3% by mass) based on time (days).

[0142] FIG. 5 represents the quantification of the intensity and the frequency of infection by mildew of young vine leaves treated or not with the mixture according to the invention.

[0143] FIG. 6 represents the quantification of the intensity and the frequency of infection by mildew of old vine leaves treated or not with the slurry according to the invention.

[0144] FIG. 7 represents the quantification of the intensity and the frequency of infection by mildew of vine leaves treated or not with the slurry according to the invention.

DESCRIPTION OF EMBODIMENTS

[0145] 1/ Preparation of the Base According to the Invention

[0146] 1.1/ Composition of the Base

[0147] The composition of a base according to the invention is presented in Table 1

TABLE-US-00001 TABLE 1 % in the Chemical Nature process Function in the finished product Mixture of phytosterols 2 Active including β-sitosterol (at least 30% m/m) CAS no. 949109- 75-5 Sucrose esters: Sucrose 6.5 1) surfactant: stabilizes the stearate (70% m/m) colloidal suspension, makes it Sucrose stearate possible to make phytosterols (30% m/m) soluble in water to pass through plant membranes 2) makes the plant cuticle permeable Water 87.3 Particle Vehicle (=the active ingredient) Benzyl Alcohol 0.7 Preservative Polyethylene glycol with a 3.5 Fluidifying Agent molar mass of 400 g/mol

[0148] 1.2/ Manufacturing of the Base

[0149] The base according to the invention is manufactured according to the following procedural steps: [0150] preparation of the oil phase corresponding to the mixture of i) of the mixture of phytosterols, ii) of polyethylene glycol and iii) of the surfactant; [0151] preparation of the aqueous phase comprising water and benzyl alcohol; [0152] mixing the oil phase and the aqueous phase by stirring until a particle size of between 1 and 10 μm is obtained.

[0153] A dilute solution of the base (or slurry) is prepared by diluting the base according to the invention in water at a concentration of 3% by density.

[0154] 2/ Evaluation of the Capacity of the Slurry According to the Invention to Reduce the Sensitivity of Soybeans in Cultivation to Water Stress

[0155] The objective of this assay is to show that the application of the slurry according to the invention on soybeans results in slowing down the consumption of water from the soil by the plant. The method consists in showing that the water reserve of the soil decreases more slowly in the treated modality than in the control modality. The assay presented was carried out under the particular pedoclimatic conditions of the experimental plots, including a water supply by irrigation, and in the year 2019.

[0156] 2.1/ Materials and Methods

[0157] 2.1.1/ Description of the Experimental Plot

[0158] The description of the experimental plot is presented in Table 2.

[0159] 2.1.2/ Modalities Tested

TABLE-US-00002 Test Soy Test Culture (Variety) Soy (ES Mentor) Seed density 130 kg/ha (680,000 seeds/ha) Set-up Bands: 0.72 ha for the treated modality/ 1.44 ha for the control modality

[0160] The description of the modalities tested is presented in Table 3.

TABLE-US-00003 TABLE 3 Dose of base Application Modality Treatment applied stage 1 Untreated Control (UC) — — 2 Slurry according 5 L/ha BBCH 21 to the invention

[0161] The application of the slurry according to the invention is made by foliar spraying, using 80 L/ha volume of the slurry, under the following climatic conditions: temperature at 21° C., hygrometry at 75%, absence of wind.

[0162] 2.1.3/ Data Collection Method

[0163] The soil water reserve is monitored using two 60 cm capacitive probes, placed in each of the modalities. The yield is measured by load cells placed in the hopper of the combine harvester.

[0164] 2.1.4/ Statistical Analyses

[0165] The effect of the treatment on the variation of the soil water reserve (W/R) is studied over the 24-hour rolling periods (12:00-11:40), and then separately over the periods of photosynthetic activity (10:00-20:20) and respiration periods (20:40-9:40). The statistical analysis uses the Test for Equal Means (Student's t-test) and multiple linear regression.

[0166] 2.2/ Presentation of the Results

[0167] 2.2.1/ Study of the Soil Water Consumption Rate

[0168] FIG. 1 represents the raw W/R variation data recorded by the probe and FIG. 2 represents the average W/R values measured over 24 rolling hours. The results of the statistical analysis are presented in Table 4 below.

TABLE-US-00004 TABLE 4 W/R variation study period 24 Hrs. 10:00 - 20:20 20:40 - 9:40 Slurry according −3.2685 −2.29 −0.92 to the invention Control −3.8031 −3.06 −0.84 ANOVA Verified Verified Verified Student test p-value 0.02367 0.0001476 0.2755 Conclusion (at the Significant Significant Insignificant threshold of 5%) reduction reduction of 8 to 15% of 15 to 40%

[0169] 2.2.2/ Measurement of the Yield

[0170] Yield data (central area of bands) are shown in Table 5.

TABLE-US-00005 TABLE 5 Modality Mean yield (kg/ha) Slurry according 4589 kh/ha to the invention Control 4454 kh/ha ANOVA Verified Student test p-value 0.004401 Conclusion Significant increase on the order of 3%

[0171] 2.3/ Conclusion

[0172] This assay shows that the application of the slurry according to the invention to soybeans at an early stage of its development (BBCH21) results in a decrease in the rate of plant water consumption from the soil (curve “Composition According to the Invention” shift from the “control” curve). In addition, it was observed that the plants treated with the composition according to the invention did not reach the wilting point, unlike the plants in the control condition. In other words, the application of the slurry according to the invention makes it possible for the plant to adapt its water consumption and not to undergo the deleterious effects of water stress.

[0173] In addition, it is apparent from these data that for the same initial W/R soil level, the treated plant optimizes its water consumption. The moment when the W/R reaches the wilting point is therefore delayed in the absence of a new water supply, and the plant will remain in its water comfort zone for a longer period. This phenomenon is not associated with a reduction in the yield of the treated modality.

[0174] 3/ Evaluation of the Capacity of the Slurry According to the Invention to Reduce the Sensitivity of Corn in Cultivation to Water Stress

[0175] 3.1/ Materials and Methods

[0176] The experimental protocol previously explained (soybean assay; Example 2) is reproduced on corn, with the conditions presented in Table 6.

TABLE-US-00006 TABLE 6 Assay Corn assay Culture (Variety) Corn (DKC 4670) Seed density 88,000 g/ha Set-up Bands (1.2 ha) Dose tested 5 L/ha Application stage BBCH 18 Method of application Foliar spray Volume of slurry 80 L/ha Climatic conditions during temperature at 21° C., hygrometry application at 75%, and absence of wind.

[0177] 3.2/ Presentation of the Results

[0178] The data are collected and processed according to the methodology presented in Example 2. The results obtained are presented in Table 7.

TABLE-US-00007 TABLE 7 W/R variation study period 24 Hrs. 10:00 - 20:20 20:40 - 9:40 Slurry according −4.51 −3.40 −1.28 to the invention Control −5.48 −4.07 −1.46 ANOVA Verified Verified Verified Student test p-value 0.00924 0.04329 0.06951 Conclusion (at the Significant Significant Insignificant threshold of 5%) reduction (significance of 16 to 18% threshold of 10%)

[0179] The yield analysis shows no significant difference between the two modalities.

[0180] 3.3/ Conclusion

[0181] According to the same reasoning as for the assay on soybeans (Example 2), this assay on corn demonstrates the effectiveness of the slurry according to the invention for reducing the rate of W/R plant consumption from the soil.

[0182] 4/ Comparative Test of the Application of the Slurry According to the Invention at Different Stages of Soybean Plantlet Growth:

[0183] The objective of this assay is to determine the optimum stage of application of the slurry according to the invention on the soybean crop.

[0184] 4.1/ Materials and Methods

[0185] 4.1.1/ Description of the Experimental Plot:

[0186] The description of the experimental plot is presented in Table 8.

TABLE-US-00008 Test Soy test Crop (Variety) Soy (ES Mentor) Set-up Bands of 1.4 ha Volume of slurry 80 L/ha Irrigation Present (frequency of 7 days)

[0187] 4.1.2/ Modalities Tested

[0188] The description of the modalities tested is presented in Table 9.

TABLE-US-00009 TABLE 9 Dose of base Application Modality Treatment applied stage 1 Untreated Control (UC) — — A Slurry according 3 L/ha BBCH 12 to the invention B Slurry according 3 L/ha BBCH 21 to the invention

[0189] 4.2/ Presentation of the Results

TABLE-US-00010 TABLE 10 Parameter A B Vegetative Greater Better leaf development branching development Resistance to Better resistance (physiological water stress observation: less leaf curl) Improved yield +3.8% +17.8% (vs TNT)

[0190] 4.3/ Conclusion

[0191] The effect of the slurry according to the invention seems optimal when it is applied to soybeans at the BBCH 21 stage. The effects observed are a stimulation of the development of the foliar system, a better resistance to water stress, and an improved yield.

[0192] 5/ Use of the slurry according to the invention as a stimulator of the germination and growth of young sorghum seedlings under controlled and optimal cultivation conditions. The objective of this assay is to evaluate the maintenance of the effect of the slurry according to the invention for stimulating the germination and growth of young sorghum seedlings.

[0193] 5.1/ Materials and Methods

[0194] The protocol consists of priming the sorghum seeds in a slurry containing the base according to the invention before culturing in a petri dish for the germination base. The base according to the invention is replaced by water in the priming solution for the untreated control. The crop parameters are shown in Table 11.

TABLE-US-00011 Parameter Crop (Variety) Sorghum (Belugga variety), seeds supplied by RAGT Initial experimental Petri dishes, containing 2 sheets of set-up Whatman paper and 6 mL of water Size of the Petri dishes 9 cm in diameter Number of seeds per 50 seeds per Petri dish dish Number of blocks 4 Petri dishes per modality Number of assays 4 assays (this study was performed 4 times) Tested doses of the 1 dose tested: 3% of the base according to the slurry according invention to the invention Mode of application of Soaking the seeds in the solution (priming) for the solution according 15 min in the 3% solution, then drying for to the invention several days on absorbent paper before culturing in the Petri dishes Number of applications 1 Date of priming 1.sup.st day of cultivation Germination conditions Germination chamber: 25° C., continuous darkness

[0195] The seeds are cultivated for 7 days. Every 24 hours after sowing (DO), the following parameters were observed: [0196] Percentage of germinated seeds; [0197] Radicle length in mm

[0198] 5.2/ Results and Conclusion

[0199] The results are shown in FIGS. 3 and 4. For the entire assay, the sorghum seeds which have been treated by soaking in a 3% solution of the base according to the invention germinate more quickly than those of the control batch. Depending on the experimental conditions, the germination rate is improved by approximately 8 hours for the treated batch compared to the control batch. This is confirmed by measuring the growth of the radicle: the size of the radicle of the treated seeds is markedly larger (1.9 times more on day 2).

[0200] 6/ Evaluation of the Capacity of the Slurry According to the Invention to Reduce the Sensitivity of the Vine in Cultivation (Young Leaves, Old Leaves and Clusters) to Mildew

[0201] The objective of this assay is to demonstrate the effectiveness of the slurry according to the invention in making the plant more resistant to biotic stress.

[0202] 6.1/ Materials and Methods

[0203] 6.1.1/ Description of the Experimental Plot:

[0204] The description of the experimental plot is presented in Table 12.

TABLE-US-00012 TABLE 12 Test Vine test Crop (Variety) Vine (Ugni blanc) Inter-row 3 meters Inter-vines 1.2 meters Experimental set-up Micro plots of 7 vines, 4 repetitions Particularities Artificial contamination Slurry dose tested 1 L/ha

[0205] 6.1.2/ Modalities Tested

[0206] The description of the modalities tested is presented in Table 13.

TABLE-US-00013 TABLE 13 Dose of Base Application Modality Treatment Applied stage 1 Untreated control — — 2 Slurry according 1 L/ha 7 applications from the to the invention visible cluster stage (BBCH 53) to the pea stage (BBCH 75)

[0207] 6.1.3/ Data Collection Method 6.1.3.1/ Measurement of Disease Development

[0208] The development of disease is assessed using two complementary indicators: [0209] Disease frequency: percentage of leaves upon which the disease is found; and [0210] Disease intensity (in %): Average disease intensity on all leaves. Thus, the intensity on a leaf corresponds to the area of the leaf covered by the disease (%).

[0211] The evaluation is carried out on young leaf, old leaf and cluster. For each organ, the sample is from 200 individuals per modality (50 per microplot).

[0212] 6.1.3.2/ Statistical Analyses

[0213] For this assay, the tests performed are: [0214] A Chi.sup.2 test of equal frequencies (Equal Means); and [0215] A Mann-Whitney-Wilcoxon test of intensity equality (Equal Means).

[0216] 6.1.4/ Presentation of the Results

[0217] The results of the tally on young leaves, old leaves and clusters are shown in FIGS. 5, 6 and 7, respectively.

[0218] 6.1.4.1/ Test of Equal Frequencies (Chi.sup.2)

TABLE-US-00014 TABLE 14 Frequency on Frequency on Frequency on Modality young leaves old leaves clusters Slurry according 75.5% 97.5%  82% to the invention Control 78.5% 100% 98% Equal means Accepted Inappropriate test Rejected p-value of test 0.4759 8.697e−8

[0219] Conclusion: the effects of the slurry according to the invention on the disease intensity are not significant on the leaves, but the disease is significantly less frequent on the clusters treated beforehand.

[0220] 6.1.4.2/ Test of Equal Means of Intensities (Mann-Whitney-Wilcoxon)

TABLE-US-00015 TABLE 15 Intensity on Intensity on Intensity on Modality young leaves old leaves clusters Slurry according 11.17% 20.76% 27.9% to the invention Control 21.87% 30.2%  45.6% Equality of medians Rejected Rejected Rejected Student test p-value 1.90e−7 2.616e−8 1.458e−11

[0221] Conclusion: on the 3 organs observed, the intensity of the disease is significantly lower on the vines having benefited from the solution according to the invention, compared to the same organs of the control method. In this assay, the intensity of the disease may be reduced by 30% to 50% by applying the slurry according to the invention to the vine.

[0222] 7/ Conditions of Use of the Slurry According to the Invention by Foliar Spraying

[0223] The preventive treatment method according to the invention makes it possible to induce an improvement in the vigor of the plant to enable it to fight effectively against abiotic and/or biotic stress. The mixture according to the invention must be applied at the inter-row coverage stage through the leaves of the plant (row sowing crop cultivation).

[0224] It emerges from the foregoing that the moment the slurry according to the invention is applied depends on the species of cultivated plant, its vegetative growth, the date of sowing and the distance of the inter-row or herbaceous part between 2 rows of seedlings.

[0225] These data are shown in Table 19 for a crop of corn, soybeans and protein seeds.

TABLE-US-00016 Spray Stage of Stage of Dose per intake Number of Dilution volume concentration crop at BBCH crop (in L/ha) intakes per year (in liters) (in kg/100 L) Intake the time at the time Crop Min. Max. Min. Max. Min. Max. Min. Max. period of intake of intake Corn 1 5 1 3 50 200 0.5 10 June 4 to 10 14-19 leaves Soy 1 5 1 3 50 200 0.5 June 4 flowering leaves Protein 4 Seeds flowering leaves