Composite fungal herbicide, preparation method and application

Abstract

The present invention provides a composite fungal herbicide, belonging to the technical field of microbial herbicides. The composite fungal herbicide comprises active herbicidal ingredients: Streptomyces hygroscopicus M22 and Curvularia lunata B6. The combined use of Streptomyces hygroscopicus M22 and Curvularia lunata B6 creates a synergistic effect, broadens the weed control spectrum, and enhances the control of field weeds. The weed control effect is superior to that of a single agent, and is superior to other microbial herbicides. Furthermore, the composite herbicide is highly safe for crops and does not cause phytotoxicity.

Description

Technical Field

[0001] The present invention belongs to the technical field of microbial pesticides, and in particular relates to a composite fungal herbicide, a preparation method and an application thereof. Background Art

[0002] In the 1950s, chemical herbicides gained widespread popularity and adoption due to their low dosage, ease of use, rapid effectiveness, and long-lasting effects. However, their widespread use has also led to numerous negative side effects, including slow decomposition and soil residues; impacts on plant physiology; reduced crop resistance and quality; changes in existing plant communities; decreased soil fertility; and groundwater contamination. Driven by the need for pollution-free, safe, and environmentally friendly crop cultivation, microbial herbicides are gaining increasing attention due to their high specificity, environmental friendliness, and safety.

[0003] "Lubao No. 1" is my country's first biological herbicide product. In the 1960s, the Plant Protection Institute of the Shandong Academy of Agricultural Sciences isolated and commercialized a strain of C. gioeosporiodes Penz Saccf.sp cuscutae from southern dodder. It was used to control dodder in soybean fields, achieving a direct control rate of 70%-90%. With the development of microbial herbicides, highly effective microbial herbicides such as "Junkekuo" have emerged. However, at this stage, my country's research and development of microbial herbicides is still relatively limited, and chemical weed control remains the primary method. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a composite fungal herbicide, a preparation method and an application thereof, which expands the herbicide spectrum and improves the control effect on field weeds by combining Streptomyces hygroscopicus M22 and Curvularia lunata B6.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A composite fungal herbicide, the active herbicidal ingredients of which are Streptomyces hygroscopicus M22 and Curvularia lunata B6.

[0007] Preferably, the concentration of Streptomyces hygroscopicus M22 is (0.2-2)×10 8 spores / mL; the concentration of the Curvularia lunata B6 is (0.2-2)×10 4 spores / mL.

[0008] More preferably, the concentration of Streptomyces hygroscopicus M22 is 1×10 8 spores / mL; the concentration of the Curvularia lunata B6 is 1×10 4 spores / mL.

[0009] The present invention also provides a preparation method of the composite fungal herbicide, comprising the following steps: solid fermentation culture to obtain spore powder of Streptomyces hygroscopicus M22 and Curvularia lunata B6, dissolving the spore powder in an organic solvent, adding 8-15% of an emulsifier, and stirring uniformly to obtain an emulsifiable concentrate of the composite fungal herbicide.

[0010] Preferably, the solid fermentation culture comprises: inoculating the hygroscopic Streptomyces M22 strain or the lunulatus B6 strain into a solid fermentation medium and culturing at 25-28° C.; the solid fermentation medium matrix is a mixture of wheat bran and corn flour in a ratio of 1-2:1, adding 0.5-1.5% ammonium sulfate and 0.2-0.4% potassium dihydrogen phosphate, and adding water to a moisture content of 40-60%.

[0011] Preferably, the organic solvent is one or more of modified vegetable oil, plant essential oil or rosin oil.

[0012] Preferably, the emulsifier is one or more of a nonionic emulsifier, a cationic emulsifier or an anionic emulsifier.

[0013] The present invention also provides application of the composite fungal herbicide in preventing and controlling rice weeds.

[0014] Preferably, the composite fungal herbicide is applied at a dosage of 60-100 mL / mu, diluted with 20-30 kg of water, and sprayed when the weeds are 2-4 leaves old.

[0015] Preferably, the weeds include one or more of Echinochloa crusgalli, Cyperus difformis, Sagittaria officinalis, Alisma orientalis, and Pleurotus eryngii.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention provides a composite fungal herbicide whose active weed-killing ingredients are Streptomyces hygroscopicus M22 and Curvularia lunata B6. The combined use of these two fungi creates a synergistic effect, broadening the weed control spectrum and enhancing the control of field weeds. The weed control effect is superior to that of a single agent alone, and is superior to other microbial herbicides. It is also highly safe for crops and does not cause phytotoxicity. DETAILED DESCRIPTION

[0018] The present invention provides a composite fungal herbicide, wherein the effective herbicidal components are Streptomyces hygroscopicus M22 and Curvularia lunata B6.

[0019] Streptomyces hygroscopicus M22 produces the herbicidal active substance bialaphos, whose active herbicidal component is an antibiotic substance with an aminophosphonic acid structure. Bialaphos, metabolized in plants as L-glufosinate, inhibits glutamine synthesis in plants, leading to ammonia accumulation, thereby inhibiting the phosphorylation of photosynthetic products during photosynthesis, leading to weed death. It has strong broad-spectrum herbicidal activity and can be used to control annual and perennial grass weeds and broadleaf weeds. Curvularia lunata B6 has certain biological activity against barnyardgrass and is highly effective in controlling weeds in rice fields. It is ecologically safe for paddy fields and has no residual toxicity. Combining Streptomyces hygroscopicus M22 with Curvularia lunata B6 to prepare a composite fungal herbicide can expand the herbicidal spectrum, improve herbicidal efficiency, and exhibit synergistic effects.

[0020] The Streptomyces hygroscopicus M22 of the present invention is disclosed in "Study on Herbicides Produced by Streptomyces hygroscopicus M-22" (Lian Yunyang, Xie Weiwei, Chen Chengbo, Xie Tingxin, Cheng Yuanrong, Lin Wenliang. Study on Herbicides Produced by Streptomyces hygroscopicus M-22 [J]. Chinese Journal of Antibiotics, 1998(02):49-51.); Curvularia lunata B6 is disclosed in CN201010149432.0, with a deposit number of CGMCCNO.2928, deposited by the General Microbiology Center of China Culture Collection Administration, with a deposit address of Datun Road, Chaoyang District, Beijing, and a deposit date of March 5, 2009.

[0021] The preferred concentration of Streptomyces hygroscopicus M22 in the present invention is (0.2-2)×10 8 spores / mL, more preferably (0.8-1.8)×10 8 spores / mL, more preferably 1×10 8 spores / mL; the concentration of the Curvularia lunata B6 is (0.2-2)×10 4 spores / mL, more preferably (0.5-1.2)×10 4 spores / mL, more preferably 1×10 4 spores / mL.

[0022] The present invention also provides a method for preparing the composite fungal herbicide, comprising the following steps: obtaining spore powder of Streptomyces hygroscopicus M22 and Curvularia lunata B6 by solid-state fermentation, dissolving the spore powder in an organic solvent, adding 8-15% of an emulsifier, and uniformly stirring to obtain an emulsifiable concentrate of the composite fungal herbicide; preferably, the emulsifier is added in an amount of 10%. The composite fungal herbicide is formulated as an emulsifiable concentrate, which has high efficacy and long-lasting efficacy, facilitates the penetration of the active ingredients into plants, enhances the toxic effect of the composite fungal herbicide, and is easy to use and has stable properties.

[0023] The present invention preferably employs a solid fermentation culture method comprising inoculating Streptomyces hygroscopicus M22 or Curvularia lunata B6 into a solid fermentation medium and culturing at 25-28°C, more preferably 27°C. Preferably, the solid fermentation medium comprises a mixture of wheat bran and corn flour in a ratio of 1-2:1, to which is added 0.5-1.5% ammonium sulfate and 0.2-0.4% potassium dihydrogen phosphate, and water to a moisture content of 40-60%. More preferably, the solid fermentation medium comprises a mixture of wheat bran and corn flour in a ratio of 2:1 (by mass), to which is added 1.0% ammonium sulfate and 0.3% potassium dihydrogen phosphate, and water to a moisture content of 50%. More preferably, the inoculum size is 10-15%.

[0024] In the present invention, the preferred organic solvent is one or more of modified vegetable oil, plant essential oil or rosin oil; further preferred organic solvent is a mixture of biodiesel and rosin oil in an equal volume ratio.

[0025] The preferred emulsifier of the present invention is one or more of a nonionic emulsifier, a cationic emulsifier or an anionic emulsifier; further preferably, the emulsifier is a mixture of calcium dodecylbenzenesulfonate and octadecylamine chloride in an equal volume ratio.

[0026] The present invention also provides the use of the composite fungal herbicide for controlling weeds in rice fields. The composite fungal herbicide is preferably applied at a rate of 60-100 mL / mu, more preferably 80 mL / mu, diluted with 20-30 kg, more preferably 25 kg, of water and sprayed on weeds at 2-4 leaf ages, more preferably at 3 leaf ages. Preferred weeds in the present invention include one or more of barnyard grass, Cyperus dimorphus, Sagittaria officinalis, Alisma orientalis, and Pleurotus eryngii. The present invention does not particularly limit the spraying method; commonly used spraying methods in the art may be used. As one possible implementation method, a backpack pesticide sprayer is used to spray the stems and leaves of the weeds.

[0027] Unless otherwise specified, the methods used in the present invention are commonly used methods in the art; the agents and materials used can be obtained through commercial means.

[0028] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0029] Example 1

[0030] A composite fungal herbicide, the active ingredient of which is Streptomyces hygroscopicus M22 at a concentration of 1×10 8 spores / mL, the concentration of Curvularia lunata B6 was 1×10 4 spores / mL;

[0031] The preparation method comprises:

[0032] (1) preparing a solid fermentation medium comprising a mixture of wheat bran and corn flour in a mass ratio of 2:1, adding 1.0% ammonium sulfate and 0.3% potassium dihydrogen phosphate, and adding water to a water content of 50%;

[0033] (2) Inoculating Streptomyces hygroscopicus M22 and Curvularia lunata B6 at an inoculum rate of 10%, respectively, and culturing at 25-28°C. During this period, the fermentation medium was supplemented with water to maintain the moisture content; after culturing for 10 days, spores on the surface of the culture medium were brushed off with a brush to collect spore powder;

[0034] (3) adding the collected spore powder to an organic solvent, adding 10% of an emulsifier, controlling the number of spores to reach an effective concentration, and stirring evenly to obtain a composite fungal herbicide emulsifiable concentrate; the organic solvent is biodiesel and rosin oil (V / V) = 1:1, and the emulsifier is calcium dodecylbenzenesulfonate and octadecylamine chloride (V / V) = 1:1.

[0035] Example 2

[0036] A composite fungal herbicide, the active ingredient of which is Streptomyces hygroscopicus M22 with a concentration of 0.2×10 8 spores / mL, the concentration of Curvularia lunata B6 was 2×10 4 spores / mL;

[0037] The preparation method comprises:

[0038] (1) preparing a solid fermentation medium, wherein the matrix is a mixture of wheat bran and corn flour in a mass ratio of 2:1, adding 0.5% ammonium sulfate and 0.2% potassium dihydrogen phosphate, and adding water to a water content of 40%;

[0039] (2) Inoculating Streptomyces hygroscopicus M22 and Curvularia lunata B6 at an inoculum rate of 12%, respectively, and culturing at 25-28°C. During this period, the fermentation medium was supplemented with water to maintain the moisture content; after culturing for 10 days, spores on the surface of the culture medium were brushed off with a brush to collect spore powder;

[0040] (3) adding the collected spore powder to an organic solvent, adding 8% of an emulsifier, controlling the number of spores to reach an effective concentration, and stirring evenly to obtain a composite fungal herbicide emulsifiable concentrate; the organic solvent is biodiesel and rosin oil (V / V) = 1:1, and the emulsifier is calcium dodecylbenzenesulfonate and octadecylamine chloride (V / V) = 1:1.

[0041] Example 3

[0042] A composite fungal herbicide, the active ingredient of which is Streptomyces hygroscopicus M22 with a concentration of 2×10 8 spores / mL, and the concentration of Curvularia lunata B6 was 0.2×10 4 spores / mL;

[0043] The preparation method comprises:

[0044] (1) preparing a solid fermentation medium, wherein the matrix is a mixture of wheat bran and corn flour in a ratio of 1:1 (mass ratio), adding 1.5% ammonium sulfate and 0.4% potassium dihydrogen phosphate, and adding water to a water content of 60%;

[0045] (2) Inoculating Streptomyces hygroscopicus M22 and Curvularia lunata B6 at an inoculum rate of 15%, respectively, and culturing at 25-28°C. During this period, the fermentation medium was supplemented with water to maintain the moisture content; after culturing for 10 days, spores on the surface of the culture medium were brushed off with a brush to collect spore powder;

[0046] (3) adding the collected spore powder to an organic solvent, adding 15% of an emulsifier, controlling the number of spores to reach an effective concentration, and stirring evenly to obtain a composite fungal herbicide emulsifiable concentrate; the organic solvent is biodiesel and rosin oil (V / V) = 1:1, and the emulsifier is calcium dodecylbenzenesulfonate and octadecylamine chloride (V / V) = 1:1.

[0047] Example 4

[0048] A method for applying a composite fungal herbicide comprises the following steps:

[0049] In the rice fields, 80 mL / mu of the composite fungal herbicide of Example 1 was applied, diluted with 25 kg of water, and the weeds in the rice fields were sprayed to the stems and leaves when they were 2-4 leaf years old.

[0050] Example 5

[0051] A method for applying a composite fungal herbicide comprises the following steps:

[0052] In the rice fields, 60 mL / mu of the composite fungal herbicide of Example 2 was applied, diluted with 20 kg of water, and the weeds in the rice fields were sprayed to the stems and leaves when they were 2-4 leaf years old.

[0053] Example 6

[0054] A method for applying a composite fungal herbicide comprises the following steps:

[0055] In the rice fields, 100 mL / mu of the composite fungal herbicide of Example 3 was applied, diluted with 30 kg of water, and the weeds in the rice fields were sprayed to the stems and leaves when they were 2-4 leaves old.

[0056] Example 7

[0057] Effects of different microbial fungicides on weed control in rice fields

[0058] To investigate the weed control efficacy of the composite fungal herbicide of the present invention, weed control experiments using different microbial fungicides were conducted in a rice field experiment at the College of Agriculture at Northeast Agricultural University. In addition to a blank control, the commonly used rice field microbial herbicides, Junkekuo and Kebaimei, were also tested.

[0059] The treatments are:

[0060] (1) Blank control; (2) Junkekuo granules, effective viable count of 2×10 5 cfu / g; (3) Echinochloa crus-galli (Helminal spore fungus of graminearum), the spore content of 1% Echinochloa crus-galli powder is 1.95×10 7 / g; (4) Streptomyces hygroscopicus M22 emulsifiable concentrate, prepared according to the method of Example 1, with a concentration of 2×10 8 spores / mL; (5) Curvularia lunata B6 emulsifiable concentrate, prepared according to the method of Example 1, with a concentration of 2×10 4 Spores / mL; (6) Hygroscopic Streptomyces M22-Curvularia lunata B6 composite fungal emulsifiable concentrate, prepared according to the method of Example 1, the concentration of hygroscopic Streptomyces M22 is 1×10 8 spores / mL, the concentration of Curvularia lunata B6 was 1×10 4 spores / mL.

[0061] Each treatment was repeated three times, and the area of each plot was 25m 2 , weed control in rice fields at the 3-leaf stage, using the recommended dosage and method, as shown in Table 1, and conduct efficacy investigation 21 days later. Efficacy investigation: adopt the diagonal 5-point sampling method, and investigate 0.25m at each sampling point. 2 , investigate the number of main weeds remaining 21 days after application, calculate the control effect, and observe whether each pesticide causes phytotoxicity to rice.

[0062] The rice variety was 'Longdao 18', and fertilization and irrigation were routine local management methods. Except for weed control measures, other field management measures were the same among all treatments.

[0063] Test results:

[0064] (1) Safety investigation: No symptoms of rice poisoning were observed in the rice plots, and the rice stalks did not show any obvious yellowing or softening during the whole process.

[0065] (2) Drug efficacy investigation:

[0066] Table 1 Control effects of different microbial fungicides on weeds in rice fields

[0067] deal with Application rate Administration Barnyard grass % Cyperus diversiformis% Wild arrowhead% Alisma % Yujiuhua% Blank control — — 0 0 0 0 0 Junkekuo 1kg / mu Broadcasting 0 51.3 30.2 53.5 62.7 Echinochloa crusgalli 0.6kg / mu Spraying 62.3 0 0 0 0 M22 80mL / mu Spraying 59.3 46.2 44.6 70.5 63.8 B6 80mL / mu Spraying 71.7 11.0 3 0 0 M22+B6 80mL / mu Spraying 80.3 60.9 70.2 72.3 70.9

[0068] As can be seen from Table 1, the combined use of Streptomyces hygroscopicus M22 and Curvularia lunata B6 has a synergistic effect, can expand the weed control spectrum, and improve the control effect of field weeds. The weed control effect is better than that of a single agent. It is also better than other microbial herbicides, and is highly safe for rice and will not cause phytotoxicity.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A composite fungal herbicide, characterized in that: The effective herbicidal ingredients are Streptomyces hygroscopicus M22 and Curvularia lunata B6; the concentration of Streptomyces hygroscopicus M22 is 1×10 8 spores / mL; the concentration of the Curvularia lunata B6 is 1×10 4 spores / mL.

2. The method for preparing the composite fungal herbicide according to claim 1, characterized in that: The method comprises the following steps: solid fermentation culture to obtain spore powder of Streptomyces hygroscopicus M22 and Curvularia lunata B6, dissolving the spore powder in an organic solvent, adding 8-15% of an emulsifier, and stirring evenly to obtain a composite fungal herbicide emulsifiable concentrate.

3. The preparation method according to claim 2, characterized in that The solid fermentation culture comprises: inoculating hygroscopic Streptomyces M22 strain or Curvularia lunata B6 strain into a solid fermentation culture medium and culturing at 25-28° C.; the solid fermentation culture medium matrix is a mixture of wheat bran and corn flour in a ratio of 1-2:1, adding 0.5-1.5% ammonium sulfate and 0.2-0.4% potassium dihydrogen phosphate, and adding water to a water content of 40-60%.

4. The preparation method according to claim 2, characterized in that The organic solvent is one or more of modified vegetable oil, plant essential oil or rosin oil.

5. The preparation method according to claim 2, characterized in that The emulsifier is one or more of a nonionic emulsifier, a cationic emulsifier or an anionic emulsifier.

6. Use of the composite fungal herbicide according to claim 1 in controlling weeds in rice, characterized in that: The weeds include one or more of Cyperus diversiformis, Sagittaria officinalis, Alisma orientalis, and Pleurotus eryngii.

7. The use according to claim 6, characterized in that The composite fungal herbicide is applied at a dosage of 60-100 mL / mu, diluted with 20-30 kg of water, and sprayed on weeds at 2-4 leaf ages.