Abstract
Effects of a high soil temperature using plastic mulch and cultivation of the resistant cultivar, ‘Peking’ on the population of soybean cyst nematode (Heterodera glycines) were investigated in the field and in an incubator with vegetable soybean (Edamame). Soybean cyst nematode eggs were inoculated into seedlings of the susceptible cultivar, ‘Fuki’, grown in incubators with soil temperatures of 25, 29 and 33°C. Soybean cyst nematode did not produce cysts containing eggs at a soil temperature of 33°C, although it did produce eggs at 25 and 29°C. In field experiments, susceptible ‘Fuki’ and the resistant soybean cultivar, ‘Peking’, were cultivated for about 3 months with or without plastic mulch. When the accumulated duration of soil temperature above 33°C was 200 hr or longer, the egg reproduction ratio was significantly suppressed and edamame yield was high the following year. After ‘Peking’ cultivation, the egg number in the soil was significantly suppressed compared to that after ‘Fuki’, and edamame yield the following year was also high.
