Study on the effects of the population dynamics of soyabean aphid (Aphis glycines) on both growth and yield of soyabean.

Abstract

Population dynamics of the soybean aphid, Aphis glycines and its effects on soybean growth and yield were surveyed in 1989-1990. Experiments were conducted in the naturally infested plots and in the treated plots using 10% enhanced Dimethoate. In 1989, soybean aphids in the untreated plots developed earlier and increased rapidly. Aphid density per 100 plants on June 15th was over 10,000, and the rapid development period was over 40 d. But aphids in 1990 developed slightly later with a shorter development period. Soybeans in the untreated plots significantly displayed the symptoms of distorted leaves, shorter stems and stunted plants. Plants in the treated plots were higher (20.2 cm in 1989) than those in the untreated plots. Soybean aphids significantly affected soybean yields. Yields in the untreated plots reduced 27.8% compared to that in the treated plots in 1989.