JPH0223522B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides an agricultural and horticultural sterilizer containing kasugamycin (hereinafter referred to as "KSM") or its salts and O-ethyl S,S-diphenyl dithiophosphate (hereinafter referred to as "EDDP") as active ingredients. In particular, the present invention provides a novel fungicide that exhibits a remarkable synergistic control effect against rice blast, rice ear blight, and rice bacterial blight. In recent years, as rice cultivation methods have become more labor-saving and mechanical transplantation of young seedlings has become widespread throughout the country, major changes have appeared in the appearance of rice diseases. In particular, the period during which rice is exposed to high temperatures during the ripening stage has become longer than ever, causing rice blast and head blight diseases due to invasion by rice sesame leaf blight fungi, rice brown leaf blight fungi, rice row blight fungi, etc. So-called rice ear blight and rice blight bacterial disease are occurring frequently.
However, it is extremely difficult to simultaneously and completely control these various diseases, and at present no fungicide has been found that is highly effective against these diseases. Therefore, there is an urgent need to develop new fungicides and control techniques that can simultaneously control these diseases in a labor-saving manner. In view of these circumstances, the inventors of the present invention have conducted extensive studies by testing a large number of drugs. As a result, KSM
It has also been found that the use of a mixture of salts thereof (for example, hydrochloride) and EDDP has an extremely excellent control effect on the above-mentioned diseases. Previously, the effect of KSM on rice diseases was mostly limited to rice blast, but recently it has been known to exhibit antibacterial activity against rice row blight fungi and control activity against rice bacterial rice blight. however,
KSM has the drawback of lacking residual efficacy and preventive spraying effect against rice blast. Furthermore, the reality is that it is difficult to expect an economical practical effect from using KSM alone against rice panicle blight caused by the invasion of various rice pathogens as described above, which has recently become a problem. On the other hand, EDDP has been put into practical use as one of the few rice ear blight control agents, but its control effect is less stable than its effect on rice blast, and it is also used against rice blight bacterial disease, which is currently a problem. No effect can be expected. The agricultural and horticultural fungicide according to the present invention complements the disadvantages of each of the above two agents, and is effective against rice blast, rice ear blight, and rice blight at a dosage lower than the usual dosage of each single agent. It exhibited extremely excellent control activity against bacterial diseases. Moreover, surprisingly, the control effect was found to be a synergistic control effect that could not be expected from the single application of each active ingredient.
The present invention was made based on these new findings, and is extremely practical as a simultaneous control agent for rice blast, as well as rice ear blight and rice bacterial blight, which have recently become a problem. To formulate the disinfectant of the present invention, various commonly used carriers and various auxiliary agents are added to the active ingredient to form powders (including DL type powders), wettable powders, liquids, flowables, fine granules, and granules. It can be used in any desired form such as a tablet or tablet. Supports used in the present invention include clay, talc, bentonite,
Solid carriers such as kaolin, diatomaceous earth, and silica, or liquid carriers such as benzene, xylene, toluene, kerosene, alcohols (methanol, ethanol, isopropanol, n-butanol, etc.), and ketones (acetone, methyl ethyl ketone, cyclohexanone) are used. be done. A suitable surfactant and other adjuvants such as stabilizers, spreading agents, etc. can be blended in appropriate amounts to form a formulation for use. The compounding ratio of the active ingredients in the present invention is 1 part of KSM or its salts to 1 part of EDDP by weight.
It is appropriate to mix up to 50 parts, but the mixing ratio can be changed as appropriate depending on the conditions at the time of application and the status of disease occurrence. Moreover, other fungicides, insecticides, herbicides, etc. can be mixed with the agricultural and horticultural fungicide of the present invention. Next, Examples of the agricultural and horticultural fungicides of the present invention will be shown. In addition, all parts in the examples indicate parts by weight. Example 1 (Wettable powder) 1.5 parts of KSM hydrochloride, 20 parts of EDDP, 15 parts of white carbon, 5 parts of lauryl sulfate, 3 parts of lignin sulfonic acid, and 55.5 parts of clay were mixed and thoroughly ground to obtain a wettable powder. . This hydrating agent can be used before or immediately after the outbreak of rice blast, rice ear blight, and rice blight with water.
By diluting it 1,000 times and spraying it on rice plants at a rate of 100 to 150 per 10 ares using an appropriate spraying device, these diseases can be controlled singly or simultaneously. Example 2 (Powder) 0.1 part of KSM hydrochloride, 2 parts of EDDP, 0.3 part of PAP (physical property improver) and 97.6 parts of clay were thoroughly mixed and ground to obtain a powder. This powder agent can be used to control rice blast, rice ear blight, and rice bacterial rice blight disease individually or simultaneously by scattering it on rice plants at a rate of 2 to 4 kg per 10 ares using an appropriate spraying device. . Next, the disease control effect of the agricultural and horticultural fungicide of the present invention will be explained using test examples. Test Example 1 (Efficacy test for controlling rice blast disease in field seedlings) Dry rice (variety: Sasanishiki) was treated with a 200 times solution of Benlate T wettable powder 20 (commercially available seed disinfectant).
After sterilization by immersion for a period of time, seed rice germinated by immersion in a conventional manner was tested using a known pest control test method [``Plant Pathology Experimental Methods'' No.
301-307 (1962)], the seedlings were sown in rows in the field. For chemical spraying, 100 ml of a prescribed concentration of each test drug solution prepared according to Example 1 was applied to each area (1 area, 1 m ² ).
Each sample was sprayed twice using a small automatic sprayer. The first spraying was carried out at the 2.8 leaf stage when the initial lesions began to appear on the lower leaves, and the second spraying was carried out 6 days after the first spraying. The disease onset was investigated 15 days after the second spraying of the chemical, and the percent percentage of dead area of blast lesions was investigated, and the percent control value of each test chemical was calculated using the following formula. Control value = (1 - Average ratio of dead area of blast lesions in sprayed area/average ratio of dead area of blast lesions in non-sprayed area) x 100 The results are shown in Table 1.

【table】

[Table] Test Example 2 (Field test on rice panicle blight control effect) As in Test Example 1, the seedlings were sterilized with Benlate T wettable powder 20, and the young seedlings were grown in boxes according to the general procedure ^. ) mechanical transplantation (cultivation density 30cm x 14cm)
did. The amount of fertilizer applied by Honda is 15 kg of Phosphorous Ammonium Chloride No. 284 and 25 kg of PK chemical containing magnesium soil as the base fertilizer per 10 ares.
In addition, 20 kg of NK chemical was applied as additional fertilizer at the highest tillering stage. The chemicals were sprayed twice, at the ear-setting stage and the milk-ripening stage, using a backpack-type power mister to spray 120 ml of each test chemical solution at a predetermined concentration per 10 ares, which was prepared according to Example 1. In the disease onset investigation, 22 days after the second chemical spraying, the disease severity of the ears was determined for 30 plants in each plot using the following disease severity criteria, and the percentage control value was determined by comparing it with the disease severity in the non-sprayed plot. The test was conducted at one concentration in triplicate, and the average control value was calculated. Additionally, ear blight due to rice sesame leaf blight was tested on the cultivar Nipponbare, and ear blight due to rice row blight was tested on the cultivar Reihou. Incidence of panicle = 4A + 2B + C / 4N × 100 N: Total number of panicles surveyed A: The head of the panicle is attacked and the entire panicle is dead B: The head of the panicle, cob or rachis is affected and half of the panicle is damaged One or more of the ears are withered and dead. C: The cob or branch stalk is damaged and less than one-half of the ears are dead. The results are shown in Table 2.

[Table] Shows the severity of the disease.
Test Example 3 (Rice rice blight bacterial disease control effect test) The 5-leaf stage seedlings of test rice (variety: Tangin) were placed in a 1/5000 are Wagner pot (fertilization amount: 0.6 for each of N, P, and K components per pot). Kg), five plants were planted one at a time, and those at the flowering stage were used. Pseudomonas glumae was used as the test fungus, and it was grown for 3 days (27°C) in Wakimoto's medium [see "Plant Pathology Experimental Methods", p. 774 (1962)].
A bacterial suspension adjusted to 10 ⁸ cells/ml after culturing was used.
Chemical spraying was carried out by spraying a prescribed concentration of each test drug prepared according to Example 1 per 10 ares one day before inoculation of the pathogen.
It was evenly distributed using a spray gun at a rate of 150%. The disease onset survey was conducted to determine the percentage of paddy blight that developed in rice plants 20 days after inoculation with the disease fungus.
The control value was determined by comparing with the non-sprayed area. The test was conducted using a three-pot system at one concentration, and the average control value (%) was calculated. The results are shown in Table 3.

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【table】

Claims (1)

[Claims] 1. An agricultural and horticultural fungicide characterized by containing kasugamycin or its salts and O-ethyl S,S-diphenyl dithiophosphate as active ingredients.