JPS6154001B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an agricultural and horticultural soil fungicide characterized by containing diphenylacetylene as an active ingredient. Soil diseases such as seedling damping-off and root-knot disease of vegetables, black sore disease of potatoes, lettuce rot disease, white silk disease of konnyaku, and black radish disease exhibit soil-phobic phenomena in crop cultivation, making continuous cropping impossible. It is often possible. Steam disinfection, heat treatment, chlorpicrin, pentachlornitrobenzene,
Disinfection methods using chemicals such as methyl bromide are becoming widespread. However, the situation is still unsatisfactory from a comprehensive standpoint, including labor, economic efficiency, danger to humans and livestock, and chemical damage to plants. The present inventors completed the present invention as a result of searching for a new drug that can control the above-mentioned soil diseases using a safe and simple method of use. The compound of the present invention is a known compound that is a white crystal with a melting point of 60° C., which can be easily obtained by brominating trans-stilbene and then melting it with an alkali. The active ingredient of the pest control agent according to the present invention can be used as it is by being mixed into topsoil as a soil disease control agent, but in reality, various inorganic or organic solid carriers are used, such as diatomaceous earth, clay, talc, ammonium sulfate, and urea. , silica gel, sawdust, lime, calcium carbonate and other powders. The compounds of the present invention may also be carried in various liquid carriers such as water, acetone, benzene, xylene, kerosene, vegetable paraffin,
It can also be used by dissolving or dispersing it in animal paraffin, oil, etc. Furthermore, in order to enhance the efficacy of the pesticidal agent of the present invention, various adjuvants such as a water-soluble base of ligninsulfonic acid, anionic surfactants such as sodium alkylbenzenesulfonate, and nonionic surfactants such as nonylphenyl polyoxyethylene ether are added. A lubricant such as a surfactant, calcium stearate, white carbon, etc. can be added and used. In addition, the active ingredient compounds of the pest control agent of the present invention include pentachlornitrobenzene, bis(dimethylthiocarbamoyl)disulfide, tetrachloroisophthalonitrile, 3-hydroxy-5-methylisoxazole, 5-ethoxy-3-trichloromethyl-1,2 ,4-thiadiazole, N-(trichloromethylthio)-4-cyclohexene-1,2-
Dicarboximide, N-(1,1,2,2-tetrachloroethylthio)-4-cyclohexene-
Fungicides such as 1,2-dicarboximide, organophosphorus insecticides, carbamate insecticides, D-D,
EDB, bis(2-chloro-1-methylethyl)
It can also be used in combination with soil nematicides (insecticides) such as ether, bromomethane, trichloronitromethane, sodium N-methyldithiocarbamate (ammonium), various herbicides, and fertilizer substances, or as a mixture. be. Next, examples of the present invention will be shown. Example 1 20 parts by weight of diphenylacetylene, 1 part by weight of polyvinyl alcohol, 3 parts by weight of sodium higher alcohol sulfonate, and 76 parts by weight of clay were ground and mixed to prepare a powder. Example 2 20 parts by weight of diphenylacetylene, xylol 70
parts by weight and 10 parts by weight of polyoxyethylene nonyl phenyl ether were mixed to prepare an emulsion. Example 3 40 parts by weight of diphenylacetylene, 5 parts by weight of polyoxyethylene alkyl allyl ether, and 55 parts by weight of diatomaceous earth with kaolin added at a ratio of 5:1 were ground and mixed to prepare a wettable powder. Next, the effects of the soil disease control agent of the present invention will be shown using test examples. Test Example 1 Test bacteria were Pythium aphanidermatum, Rhizoctonia solani, and Pellicularia rolfsii.
was used, and cucumber (variety four-leaf cucumber) was used as the test plant. Incubate the test bacteria in bran medium at 26°C.
After culturing for one day, the mixture was mixed well with 100 g of dry sterilized black soil and 30 ml of sterile water, and the mixture was cultured at 28°C for 2 days to serve as an inoculum. 150 ml of black soil was placed in a pot with a diameter of 9 cm, each pot was coated with 10 g of the above-mentioned inoculum, and after inoculation, the pot was allowed to stand for 5 days, and after stirring and degassing, the seeds were sown. After that, they were grown in a greenhouse at 25° to 30°C for 12 days, and the number of healthy seedlings was investigated. The number of seeds sown for the test plants was 10 per pot.
There were two pots per ward for each grain. The disease attack rate was calculated using the following formula and expressed as the average value for two pots. Incidence rate (%) = Number of standing plants in the chemical treated area / Number of standing plants in the non-treated area x 100 The test results are shown in the table below.

[Table] Test Example 2 4 ml of a suspension of dormant spores (spore density: 10 ⁶ spores/ml) of the clubroot fungus (Plasmodiophora brassicae), which causes clubroot disease of cruciferous vegetables, and 200 g of sterilized black soil and sand mixed soil were thoroughly mixed. Mix, place in a pot with a diameter of 9 cm, treat with the test chemical at the specified concentration, and heat at 25° to 30°C.
It was kept in a greenhouse. After 3 days, the gas was removed and Chinese cabbage (variety: Osho) was sown, and then kept in a constant temperature room at 25℃.
Seedlings were grown for 12 days. The roots of young seedlings were dyed without being cut, immersed in a staining solution for 24 hours, and the number of fungal-infected root hairs was observed under a microscope to investigate the disease incidence. The number of test plants sown was 10 seeds per pot and 3 seeds per plot.
The disease attack rate was calculated using the following formula and expressed as the average value of 3 pots. Incidence rate (%) = Number of root hair infections in drug-treated area/Number of root hair infections in untreated area x 100 The test results are shown in the table below.

[Table] *Pentachlornitrobenzene

Claims (1)

[Claims] 1. An agricultural and horticultural soil fungicide characterized by containing diphenylacetylene as an active ingredient.