Water Loss from Soybeans After Simulated and Actual Insect Defoliation

Publisher Website
Google Scholar
Abstract
Soybean water loss after defoliation was investigated in two experimental systems, excised leaves and field-grown potted plants. Transpiration from excised leaves increased after defoliation, as a linear function of cut edge per leaf. In contrast, transpiration from soybean canopies decreased after defoliation by two lepidopteran defoliators, the green cloverworm ( Plathypena scabra [F.]) and the cabbage looper ( Trichoplusia ni [Hübner]), and two simulation methods, punching holes in leaflets and picking entire leaflets. Cut leaf edge, an important determinant of water loss from excised leaves, only increased water loss in the first 16 h after defoliation. Defoliation methods also produced transitory differences in transpiration rates during the first 16 h after defoliation. These differences seemed related to the “hole” characteristics produced by the methods. Total water loss did not differ significantly between methods. Therefore, both punch and pick simulation methods produced acceptable fidelity to actual insect defoliation.