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COMBINED EFFECTS OF PESTICIDE ON GROWTH AND NUTRITIVE COMPOSITION OF SOYBEAN PLANTS

ZAMIN SHAHEED SIDDIQUI* AND SOALIHA AHMED

Abstract: The present study was carried out in a field located at Department of Botany, University of Karachi where soil was treated with various concentrations of pesticides before sowing. Combined effects of pesticides on soybean growth and nutritive composition of seeds were observed. Pesticide treated soil had significant effects on leaf growth components such as leaf area ratio, leaf area index, specific leaf area, net assimilation rate, leaf weight ratio and leaf area duration. Low concentration of pesticide enhanced leaf growth components at all the growth stages studied. The plants grown at the site treated with 0.25g L^-1 pesticide, displayed maximum relative growth rate (RGR) and crop growth rate (CGR) compared to control. However, significant reduction in CGR and RGR were recorded at the sites treated with 0.5 and 0.75g L^-1 concentration. Total phenols in leaf, shoot and fruit were used as a stress indicator to ascertain the possibility of chemical stress caused by systemic pesticide. 114 and 220% increase in total phenol at vegetative stage and 50, 166 and 163% at late fruiting stage were recorded in the sites treated with high pesticide concentration. Significant differences in nutritive values of seeds between treated and control plants were also observed. At the site treated with low pesticide concentration, lipid content was very high (28.9%) compared to the control. With increasing concentration, protein and lipids contents started to decline. Present study showed the combined effects of pesticides concentration on plant growth and nutritive composition of seeds.

Stress Physiology & Environmental Pollution Lab., Department of Botany, University of Karachi, Karachi, 75270 -Pakistan.
Corresponding Author: zaminsiddiqui@yahoo.co.in