大豆蚜量和蚜害时期对大豆产量的影响

Effects of Aphid Population Density and Damage period on Soybean Yield

This paper discussed the effects of aphid population density and dam- age period on soybean yield by controlling the peroid and degree of dam- age. The results of 1988 and 1986 showed that soybean has remarkable ability of compensation and tolerance to aphid damage. The yield loss caused by aphid is relatied to the insect ensity, the lasting period, and the coincidence between damage period and soybean developmental stage. During earlier stage, light damage or heavy damage controlled immediatly can't cause reduction of the yield, and if the aphid appears later in the field, the result will be similar. However, a continiuous and heavy injury would cause 20%--30% yield loss.