Bioefficacy and Fate of Pendimethalin Residues in Soil and Mature Plants in Chickpea Field

In modern agriculture, use of herbicides has become indispensable for managing weeds in cultivated lands, due to the scarcity of labors in almost all parts of the globe. Herbicides provide effective weed control in agriculture, yet their continuous and excessive use may pose serious health and environment threats. Pendimethalin is proved to be a very effective pre-emergence herbicide for the control of annual weeds in leguminous and other vegetable crops. Therefore bio-efficacy and residues of pendimethalin were determined in chickpea (Cicer arietinum L.) crop at farmers’ field. Pendimethalin was applied at 796 g ha^-1 as a pre-emergence herbicide to control weeds in chickpea fields. Pendimethalin was found effective against weeds viz. Vicia sativa, Convolvulus arvensis, Chenopodium album and Lathyrus sativa. Terminal residues of pendimethalin were found below 0.001 μg g^-1 in the chickpea grains and straw samples. However, in the soil, residues were found to be between 0.001 to 0.0029 μg g^-1. The study showed degradation of pendimethalin to the legal maximum residues limit (MRL, 0.05 mg kg^-1) in the chickpea grains. Based on this study a pre-harvest interval of 131 days was suggested for chickpea crops after pendimethalin application.