Chemical agent for killing rape seedling, its preparation method and application

Abstract

The application discloses a rape chemical growth retardant, a preparation method and application thereof, and belongs to the field of agricultural technology. A kind of rape chemical growth retardant is prepared by mixing difenoxure solution and mesotrione according to the proportion of 7.5mL:15g.The rape chemical growth retardant can improve the dehydration efficiency of rape after acting on rape, and can also improve the offspring yield of rape seed, increase seed vigor, improve germination potential and germination rate and other factors, providing a new method for improving rape mechanization seed production, breeding efficiency and seed quality.The active ingredients of the product are two low-toxicity desiccants, which have low toxicity residue, weak toxicity, low cost, good effect and other characteristics.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of agricultural technology, and particularly relates to a chemical desiccant for oilseed rape, a preparation method and application thereof. BACKGROUND

[0002] Brassica napus belongs to Cruciferae, and is one of the important oil crops in the world. China is a big country in rapeseed consumption and planting, with a planting area of 110 million mu, ranking the fifth among the five crops with a planting area of over 100 million mu. Rapeseed oil is a high-quality oil source commonly consumed and loved by Chinese people, with an annual consumption of over 8 million tons. In recent years, rapeseed has encountered many problems, such as a large gap between domestic and foreign rapeseed production costs, a huge price difference between domestic and foreign markets, generally low domestic rapeseed production scale, and insufficient agricultural mechanization level. The rapeseed sowing area in China has started to decline, farmers' willingness to plant rapeseed is low, and the average household rapeseed planting scale is decreasing. In China, the harvesting cost accounts for 30-40% of the total cost, and the use of mechanical harvesting to reduce the harvesting cost is an important means to improve the competitiveness of rapeseed in China. Therefore, how to increase the yield per mu of rapeseed and facilitate mechanical harvesting at the same time is an urgent problem to be solved, and the limiting factor of rapeseed mechanized production and seed production is the key factor of mechanical harvesting. Rapeseed is an indeterminate inflorescence, with a flowering period of 20-30 days, resulting in inconsistent maturity of the silique, and precipitation during the harvesting period often leads to slower dehydration. At present, rapeseed production and breeding generally adopts segmented harvesting, but the cost of segmented harvesting is relatively high, and is greatly affected by precipitation during the harvesting period. One-time combined harvesting and threshing are more difficult, the mechanical harvesting loss can be over 20%, and the high moisture content of the seeds is prone to mold and deterioration, resulting in a decrease in seed germination rate and vigor, and a significant decrease in the yield and quality of production and breeding.

[0003] Desiccant is a kind of chemical drying agent, herbicide, plant regulator, etc., which is sprayed on crops such as rapeseed, rice and potato at the physiological maturity stage, so that the leaves, seeds and stems of the crops can be quickly dehydrated and dried, seed maturity can be promoted, drying time can be reduced, and production efficiency can be improved.

[0004] The commonly used enemy grass quick in production is a kind of toxic bipyridyl herbicide, which is applied to most broad-leaved plants and a small part of gramineous crops for ripening. Its mechanism of action is that the strong reducing bipyridyl compound is rapidly oxidized under light catalysis to form hydrogen peroxide, which inhibits the electron transfer of plant chloroplast photosynthesis, destroys the cell membrane, and makes the sprayed surface quickly die. SUMMARY

[0005] In view of the problems in the prior art, the present application provides a chemical desiccant for oilseed rape, a preparation method and application thereof. The chemical desiccant for oilseed rape can improve the dehydration efficiency of oilseed rape after being applied to the oilseed rape, and can also improve the offspring yield of rapeseed, increase seed vigor, improve germination potential and germination rate, and has low toxicity.

[0006] To achieve the above object, the present application provides the following technical solutions.

[0007] A rape chemical ripening agent, which takes a compound of difenoxuron and mesotrione as the main active ingredient.

[0008] Further, the dosage ratio of the difenoxuron solution to mesotrione is 7.5 mL: 15 g.

[0009] Difenoxuron belongs to the carotenoid biosynthesis inhibitor, which causes chlorophyll destruction and cell rupture, and plant death. It is a broad-spectrum selective herbicide for wheat field. It has a long residual period in soil. It is suitable for various broadleaf weeds in barley and wheat fields. It is a low-toxicity herbicide. The acute oral LD 50 >2000 mg / kg in rats, and the acute dermal LD 50 >2000 mg / kg in rats. It has no carcinogenic, teratogenic, and mutagenic effects.

[0010] Mesotrione is a benzoylcyclohexanedione herbicide, which is an effective competitive hydroxyphenylpyruvate dioxygenase (HPPD) enzyme inhibitor. It has selectivity for corn crops, fast metabolism in susceptible crops, and high tolerance. The acute oral LD 50 >5000 mg / kg in rats. The acute dermal LD 50 >2000 mg / kg in rats. It is a low-toxicity herbicide. It has no irritation to rabbit skin and mild irritation to rabbit eyes. The guinea pig skin allergy (sensitization) test result is non-sensitizing.

[0011] Further, the effective ingredient content of the difenoxuron solution is 41%. The solvent for preparing the difenoxuron solution is water.

[0012] The present application also provides a preparation method of the rape chemical ripening agent, which comprises the following steps: mixing difenoxuron solution and mesotrione in proportion, and stirring uniformly to obtain the rape chemical ripening agent.

[0013] The present application also provides an application of the rape chemical ripening agent in promoting rapid dehydration of crops, and the crops are rape.

[0014] Further, during use, the dilution multiple of the rape chemical ripening agent is 100 times, that is, the rape chemical ripening agent is mixed with water in a proportion of 1:100 by volume.

[0015] The present application also provides a method for promoting rapid dehydration of rape, which sprays the rape chemical ripening agent on the surface of rape plants during the maturation period of rape.

[0016] Further, the spraying time is the middle maturation period of the rape, i.e. the seed grains of the lower siliques of the main racemes are black, the seed grains of the middle siliques are brown, and the seed grains of the upper siliques are green.

[0017] Compared with the prior art, the present application has the following advantages and technical effects:

[0018] The rape chemical catalytic agent prepared by the present application can improve the dehydration speed of the rape, increase the offspring yield of the rape seeds, increase the seed vitality, and improve the germination potential and germination rate of the seeds under the condition of a small use amount.

[0019] The preparation method of the present application is simple, convenient to operate, and the selected raw materials have low toxicity. DETAILED DESCRIPTION

[0020] Various exemplary embodiments of the present application will now be described in detail, which should not be considered as limiting the present application, but rather as a description of certain aspects, features and embodiments of the present application.

[0021] It should be understood that the terms used in the present application are merely used to describe particular embodiments and are not intended to limit the present application. In addition, for the numerical range in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or stated range and any other stated value or intermediate value within the stated range is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict between the content of the specification and that of any document incorporated herein by reference, the content of the specification prevails.

[0023] Various modifications and changes can be made to the specific implementation of the present application described in this specification without departing from the scope or spirit of the application. Other implementations of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The specification and examples given herein are exemplary and are not intended to be limiting.

[0024] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean "including but not limited to".

[0025] Test materials used in the present application:

[0026] The rapeseed variety is Sunshine 2009, and the approval number is Guoshenyou 2011009. It is bred by the Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and provided by Wuhan Zhongyou Sunshine Times Seed Co., Ltd.

[0027] Liduogu (the effective ingredient is benthiocarb), pesticide registration number: PD20070058, dipyridyl, non-selective crop defoliant.

[0028] diflufenican, pesticide registration number: PD20211630, anilide herbicide, suspension concentrate.

[0029] mesotrione, pesticide registration number: PD20212513, systemic herbicide, water dispersible granule.

[0030] The following examples are further illustrations of the technical solutions of the present application.

[0031] The "spraying amount" described in the following examples refers to the spraying amount of the pesticide preparation, which needs to be diluted with water during the spraying process.

[0032] Example 1

[0033] Preparation of rapeseed chemical defoliant:

[0034] 1) 7.5 mL of diflufenican suspension was added to water to make up to 300 mL, and a diflufenican solution with an effective mass concentration of 10.25 mg / L was prepared;

[0035] 2) 300 mL of diflufenican solution with an effective mass concentration of 10.25 mg / L was mixed with 15 g of mesotrione, and stirred uniformly to obtain a rapeseed chemical defoliant.

[0036] Field test:

[0037] 1. The test was conducted in the fall of 2022 in the test field of the Changjiang University Science and Technology Industrial Park Test Base (30°36'N, 112°08'E) in Taohu Town, Jingzhou City, Hubei Province. The test site is located in the hinterland of Jianghan Plain, with sandy loam soil, suitable climate, abundant rainfall all year round without drought and waterlogging, pH value 8.1, soil organic matter content 14.79 g / kg, alkali-hydrolyzable nitrogen 42.8 mg / kg, available potassium 75.7 mg / kg, and available phosphorus 17.3 mg / kg. The previous crop was soybean. Sowing was carried out on October 5, 2022 before rainfall, and the plot area was 20 m 2 , with a 1 m interval between plots as an isolation belt, a 2.5 m wide compartment, and a 0.5 m wide ditch.

[0038] In the middle of May 2023, when the rape is in the middle of the mature stage, the rape chemical growth retardant prepared in Example 1 (the dilution liquid obtained by diluting the prepared rape chemical growth retardant 100 times with water is the actual use growth retardant, and the spraying amount is 30 L / acre), the solution of 0.205 mL / L of trifluride solution (the spraying amount is 15 mL / acre), the spraying amount of 30 g / acre of nicosulfuron, and the spraying amount of 100 mL / acre of 200 g / L of Lijiugu are sprayed on the rape, respectively, to study the influence of spraying days on rape. The water treatment is blank control, and 2 times are repeated.

[0039] 2. Rape quality test method

[0040] 1. Moisture content: cut the rape silique and stem, and put them into the aluminum box which has been weighed, respectively, to weigh the fresh weight of rape silique and stem (Wf), and put the materials and aluminum box into the oven which has been preheated to 105℃, and fix green for 20 min, and place in the oven at 80℃ to dry to constant weight, and weigh the dry weight (Wd). The moisture content of the plant is calculated by the following formula:

[0041]

[0042] 2. Loss rate: before and after spraying the chemical rape chemical growth retardant, 4 sticky boards (the area of the sticky board is 32*9 cm 2 ) are placed on the ground of the main crown coverage of rape, and after the rape plot is harvested, the sticky boards are collected, the seeds are counted, and the estimated value of the yield loss per acre is calculated.

[0043] Table 1 Influence of spraying for 1 day on rape

[0044]

[0045] Table 2 Influence of spraying for 3 days on rape

[0046]

[0047] Table 3 Influence of spraying for 5 days on rape

[0048]

[0049]

[0050] Table 4 Influence of spraying for 7 days on rape

[0051]

[0052] As can be seen from Table 1 to Table 4, after the rape chemical desiccant prepared by the method of Example 1 of the present application is sprayed for 7 days, the water content of the silique and stem of the rape is the lowest, indicating that the dehydration rate is faster, and as the action time is prolonged, the water content decreases obviously. Although the water content of the silique and stem of the rape is not much different from that of the rape chemical desiccant prepared in Example 1, even lower at 5 days after spraying, but compared with Example 1, its toxicity is too high, and considering comprehensively, the rape chemical desiccant in Example 1 is the best, and is more conducive to rapid dehydration of the rape.

[0053] Table 5 Loss rate of rape seeds

[0054]

[0055] As can be seen from Table 5, when the rape chemical desiccant prepared by the method of Example 1 of the present application is used on rape, the loss rate of the obtained rape seeds is obviously reduced.

[0056] Comparative Example 1

[0057] The difference from Example 1 is that 10 mL / acre of the fluthiacet-methyl solution is mixed with 10 g / acre of mesotrione to prepare the rape chemical desiccant.

[0058] The test method is the same as that of Example 1.

[0059] It is found that when the rape is in the middle stage of maturity, after the rape chemical desiccant prepared by this comparative example is sprayed for 7 days, the water content of the silique is 12.53%, the water content of the stem is 34.54%, and the theoretical loss rate is 11.52%.

[0060] Comparative Example 2

[0061] The difference from Example 1 is that 5 mL / acre of the fluthiacet-methyl solution is mixed with 20 g / acre of mesotrione to prepare the rape chemical desiccant.

[0062] The test method is the same as that of Example 1.

[0063] It is found that when the rape is in the middle stage of maturity, after the rape chemical desiccant prepared by this comparative example is sprayed for 7 days, the water content of the silique is 11.72%, the water content of the stem is 34.54%, and the theoretical loss rate is 35.84%, and the theoretical loss rate is 12.33%.

[0064] Comparative Example 3

[0065] Preparation of the rape chemical desiccant:

[0066] 1) Fluthiacet-methyl is added to water to prepare a fluthiacet-methyl solution with an effective mass concentration of 0.25 ml / L;

[0067] 2) 5 mL / acre of difenoxuron solution is mixed with 10 g / acre of mesotrione and 33 mL / acre of paraquat to obtain a chemical ripener for rape.

[0068] The test method is the same as that of Example 1.

[0069] It is found that, when the rape is in the middle stage of maturity, the water content of the silique is 8.76% and the water content of the stem is 33.61% after 7 days of spraying the chemical ripener for rape prepared by using the present comparative example, and the theoretical loss rate reaches 7.4%.

[0070] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any changes or replacements easily conceived by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. The use of a chemical desiccant for Brassica in promoting rapid dehydration of the crop, characterised in that, The crop is rape; The rape chemical growth retardant is prepared by mixing 300 mL of a diflufenican solution with an effective mass concentration of 10.25 mg / L and 15 g of mesotrione.

2. Use according to claim 1, characterized in that, The preparation method of the rape chemical growth retardant comprises the following steps: mixing a diflufenican solution and mesotrione in proportion, and stirring uniformly to obtain the rape chemical growth retardant.

3. Use according to claim 1, characterized in that, During use, the rape chemical growth retardant is diluted by 100 times.

4. Use according to claim 1, characterized in that, The method for promoting the rapid dehydration of rape is that the rape chemical growth retardant is sprayed on the surface of rape plants during the maturation period of rape.

5. Use according to claim 4, characterized in that, The spraying time is the middle maturation period of rape.

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