CN108432759A - A kind of composition for preventing plant disease caused by sickle-like bacteria - Google Patents

Abstract

The invention relates to a composition for preventing and treating plant diseases caused by Fusarium, which is characterized in that the weight ratio of cyclostrobin and folpet or pyraclostrobin is 1‑50:50‑1, which is used for preventing and treating The synergistic effect is obvious for wheat head blight, rice bakanae disease, and melon wilt.

Description

Composition for preventing and treating plant diseases caused by Fusarium

technical field

The invention belongs to the field of agricultural fungicides, and in particular relates to a composition for preventing and treating plant diseases caused by Fusarium, which is used for preventing and treating wheat scab, rice bakanae disease and melon wilt.

Background technique

Wheat scab is a worldwide disease, which occurs in all major wheat-producing countries. In my country, it mainly occurs in the Jianghuai and eastern coastal areas. In recent years, the occurrence of wheat scab has shown a trend of expanding northward and westward, and the occurrence area has expanded year by year. , the prevalence of the disease intensified; the disease not only caused serious yield loss, but also produced deoxynivalenol toxin in the diseased grains, which seriously threatened human health and food safety. Rice bakanae disease, also known as excessive growth disease, is a kind of seed-borne disease, which occurs in every rice area in my country. Diseased grains often do not germinate or cannot be unearthed after sowing. The diseased seedlings are thinner and taller than the healthy seedlings at the seedling stage, the leaf sheaths are slender, the leaf color is light yellow, the root system is underdeveloped, and some diseased seedlings die before transplanting. Those with mild disease head early, and the ear shape is small and unreal. Grains at the heading stage can also be damaged, severely browned, and unable to set fruit. Therefore, the disease seriously threatens the yield of rice and poses serious challenges to world food security production. Fusarium wilt of melons, also known as wilting disease and vine cutting disease, is one of the important diseases of melons. It occurs all over the country. Cucumber and watermelon are the most serious diseases, followed by winter melon and muskmelon. Symptoms appear one after another after the plants bloom and bear fruit. In the early stage of the disease, the leaves of the diseased plants gradually turn yellow, wilt, and appear to be dehydrated. The wilting can still recover at night, and the whole leaves wither and die after a few days. Sometimes there will be half of the disease on the same disease, and the half will not. The stem base of the diseased plant is slightly constricted, brown streaks appear on the stem nodes, and rosin-like gums often flow out, and the epidermis of the stem base is often longitudinally cracked. Moisture enters, and the surface of the diseased part produces a white or pink mold layer. The longitudinal part of the diseased stem was inspected, and the vascular bundles were brown. The onset of the seedlings was dehydration and wilting, and the stem base turned brown and constricted to damp down.

At present, due to the lack of gene resources for disease-resistant breeding, chemical control is still the most effective control measure to control plant diseases. However, the long-term use of chemical agents is likely to lead to the emergence of pathogenic bacteria resistance, resulting in increasing dosage and increased risk, which is not conducive to sustainable development. In order to delay or overcome the formation and development of pathogenic bacteria resistance, the continuous use of a single fungicide should be avoided as far as possible, but should be used in rotation or mixed with other types of fungicides, and the compounding of pesticides is one of the main ways to solve the occurrence of resistance. According to the applicant's preliminary search, no report was found on the combined use of cyprostrobin, folpet or pyraclostrobin to control wheat head blight, rice bakanae disease, and melon wilt.

On the basis of indoor screening and field experiments, the inventor compounded cyclostrobin with fendan or pyraclostrobin, and found that it has obvious effects on wheat head blight, rice bakanae disease, and melon wilt. Effect, through further research, has completed the present invention.

Contents of the invention

The technical problem to be solved by the present invention is to provide a composition with good bactericidal effect, low drug cost, wide bactericidal spectrum and significant synergistic effect on wheat head blight, rice bakanae disease and melon wilt. In order to solve the problems of the technologies described above, the present invention provides technical solutions as follows:

A composition for preventing and treating plant diseases caused by Fusarium, characterized in that the active ingredients are cyclostrobin and folpet or pyraclostrobin, cyclostrobin and folpet or pyrazastrobin The weight ratio is 1-50:50-1, and the preferred weight ratio is 1-30:30-1. In some preferred technical solutions: the weight ratio of cyclostrobin and folpet or pyraclostrobin can be 1:50, 1:40, 1:30, 1:20, 1:10, 1:1, 10:1, 20:1, 30:1, 40:1, 50:1; the content of the active ingredient is 1 -90%, preferably 20-75%.

The composition of the present invention is mainly used for preventing and treating wheat scab, rice bakanae and melon wilt, and can also be used for preventing and controlling fungal diseases that occur at the same time, such as wheat powdery mildew, wheat rust, rice sheath blight and the like.

The composition of the present invention can be formulated according to methods known to those skilled in the art, including water-dispersible granules, wettable powders, suspension concentrates, aqueous emulsions, microemulsions, etc. When preparing the above-mentioned preparations, it can be prepared according to It is necessary to add known auxiliary agents, such as emulsifiers, wetting and dispersing agents, suspending agents, disintegrating agents, binders, antifreeze agents, thickeners, stabilizers, antifoaming agents and other suitable auxiliary agents in pesticides. All can be used in the present invention.

Advantage of the present invention is obvious, mainly shows in:

1. There is no antagonistic effect between cyprostrobin of the present invention and folpet or pyraclostrobin, and the synergistic effect on wheat scab, rice bakanae and melon fusarium wilt is remarkable;

2. The composition of the present invention expands the bactericidal spectrum and has a better bactericidal effect;

3. The combination and synergy of the composition of the present invention can reduce the usage amount of each single agent, has low cost and is easy to popularize.

Detailed ways

The present invention will be further described below in conjunction with the examples. The percentages in the examples are weight ratios, but the present invention is not limited thereto.

1. Indoor activity determination:

The indoor toxicity test method is as follows: the original medicines of cyclostrobin, folpet and pyrazastrobin are prepared into the required liquid medicine according to the set ratio concentration, and they are set aside. For the test method, refer to "NY/T 1156.2-2006 Indoor Bioassay Test Guidelines for Pesticides, Fungicides Part 2: Plate Method for Inhibition of Mycelia Growth of Pathogenic Fungi".

Under sterile conditions, quantitatively add pre-thawed medium into a sterile Erlenmeyer flask, sequentially draw the liquid medicine from low concentration to high concentration, add to the above-mentioned Erlenmeyer flask respectively, and shake well. Then pour it into three or more petri dishes with a diameter of 9 cm to prepare drug-containing plates of corresponding concentrations. The treatment without drug was used as blank control. Repeat 4 times.

Under aseptic conditions, use a puncher with a diameter of 5mm to take out the plate of the cultured pathogenic bacteria from the edge of the colony, inoculate the plate on the center of the plate containing the medicine with an inoculation needle, and cultivate it at 25°C for 4 days. The diameter of the colony is measured by the cross method, and the effective medium dose ( _EC50 value) of different treatments to inhibit the growth of pathogenic bacteria by 50% is calculated according to the following formula, and the antibacterial activity is compared.

The co-toxicity coefficient method is used to evaluate the synergistic effect of the fungicidal composition containing cyprostrobin, folpet and pyraclostrobin provided by the invention on wheat scab and rice bakanae bacteria by mycelial growth inhibition method, Calculate the regression equation with the logarithm of the agent concentration and the probability value of the control effect, and calculate the EC ₅₀ value of the agent pair, and then obtain the co-toxicity coefficient. The co-toxicity coefficient was used to evaluate the combined effect of the compound agents on wheat scab and rice bakanae. The co-toxicity coefficient > 120 was indicated as synergistic effect, and the co-toxicity coefficient between 80 and 120 was expressed as additive effect. Coefficients <80 indicate antagonism.

Compositions of different proportions of table 1 are to the combined effect measurement result of wheat head blight

Table 2 Compositions of different ratios to the combined action assay results of rice bakanae pathogen

The measurement results of Table 1 and Table 2 show that the composition of cyprostrobin, folpet, and pyraclostrobin is within the ratio range of 1-50:50-1, and it is effective against wheat scab and rice bakanae bacteria. It has obvious synergistic effect, and the drug effect is obviously better than that of each single agent alone.

2. Preparation Examples

Below in conjunction with the examples the present invention is further described, the percentages in the examples are all weight ratios, but the present invention is not limited thereto, the processing technology of the various dosage forms of the composition of the present invention is prior art, can have according to different situations changed.

20% suspending agent

Element Example 1 Example 2 Cyclostrobin 10 10 Folpet 10 — pyraclostrobin — 10 Alkylphenol polyoxyethylene ether 11 12 calcium lignosulfonate 10 9 Calcium dodecylbenzenesulfonate 7 7 xanthan gum 1 1 water Make up 100 Make up 100

40% WP

40% water dispersible granules

Element Example 5 Example 6 Cyclostrobin 10 10 Folpet 30 — pyraclostrobin — 30 Ethoxylated castor oil 9 10 Sorbitan Fatty Acid Ester 6 7 Sodium dodecyl sulfate 3 2 Propylene Glycol 0.5 0.5 diatomite Make up 100 Make up 100

50% water emulsion

Element Example 7 Example 8 Cyclostrobin 20 20 Folpet 30 — pyraclostrobin — 30 Alkylphenol polyoxyethylene ether 8 7 SDBS 5 6 xanthan gum 1 1 Propylene Glycol 0.5 0.5 water Make up 100 Make up 100

50% EC

3. Field efficacy test

Test Example 1

Drugs for testing: Examples 1-10 and contrasting drugs.

Comparative drug:

25% cyclostrobin suspension concentrate (comparison drug 1);

50% folpet wettable powder (comparison agent 2);

50% pyraclostrobin suspension (control agent 3).

Control crops: wheat.

Control object: Wheat head blight

Scab test method: According to the area of the test plot (about 20m ² ), accurately weigh each agent, and after diluting with water, use a knapsack sprayer to spray once at the early stage of flowering, once after 7 days, and apply in total Take the medicine twice, and investigate the disease index and calculate the control effect after about 15 days. The results are shown in Table 3.

Table 3 field efficacy test result of composition of the present invention to wheat scab

Field test results showed that the compounding of cyclostrobin and folpet or pyraclostrobin had a better control effect on wheat head blight, compared with the control example, the activity had been greatly improved, and the synergistic effect was obvious. The dosage is reduced. According to the visual inspection in the field, within the range of the test dose, the crops grew normally, and no phytotoxicity and abnormal phenomena were seen on the plants, which is safe for wheat.

Test Example 2

Drugs for testing: Examples 1-10 and contrasting drugs.

Comparative drug:

25% cyclostrobin suspension concentrate (comparison drug 1);

50% folpet wettable powder (comparison agent 2);

50% pyraclostrobin suspension (control agent 3).

Control crops: rice.

Control object: rice bakanae disease

Test method: adopt seed soaking treatment, carry out seed soaking treatment according to the dose in Table 4 for test agent,

Seeds were soaked in a constant temperature box at 25°C for 48 hours and germination was accelerated for 72 hours, and then sowed in cement ponds. Seedlings were raised in dry seedling cultivation. The diseased plant rate of each treatment was investigated at the 3-4 leaf stage after sowing, and the disease prevention effect was calculated. Three repetitions were set up for each treatment, and the specific results are shown in Table 4.

Table 4 field efficacy test results of compositions of the present invention to rice bakanae disease

Field test results show that the combination of cyclostrobin and folpet or pyraclostrobin has a better control effect on rice bakanae disease. Compared with the control example, the activity has been greatly improved, and the synergistic effect is obvious. The dosage is reduced. According to the visual observation in the field, within the range of the test dosage, the crops grew normally, and no phytotoxicity or abnormal phenomena were seen on the plants, which is safe for rice.

The above description is a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (7)

1. a kind of composition for preventing plant disease caused by sickle-like bacteria, which is characterized in that active ingredient is 2-cyano-3-amino-3-phenylancryic acetate It is 1-50 with folpet or the weight ratio of azoles mepanipyrim, 2-cyano-3-amino-3-phenylancryic acetate and folpet or azoles mepanipyrim:50-1, preferred weight ratio For 1-30:30-1.

2. composition according to claim 1, which is characterized in that active ingredient is 2-cyano-3-amino-3-phenylancryic acetate and folpet.

3. composition according to claim 1, which is characterized in that active ingredient is 2-cyano-3-amino-3-phenylancryic acetate and azoles mepanipyrim.

4. according to any compositions of claim 1-3, which is characterized in that the content of active ingredient in the composition is 1- 90%, preferably 20-75%.

5. according to any compositions of claim 1-4, it is characterised in that active ingredient with allow on pesticidal preparations it is normal Rule auxiliary agent is configured to any one dosage form allowed on pesticide.

6. composition according to claim 5, which is characterized in that the dosage form is water dispersible granules, wettable powder, outstanding breast Agent, aqueous emulsion, microemulsion.

7. the composition of claim 1-6 is used to prevent the application of wheat scab, bakanae disease of rice, cucurbits fusarium wilt.