The effect of aqueous solution of pre-emergence herbicides (i. e. trifluralin and pendimethalin) at 0, 5, 10, 15 and 20 ppm on the activity of ribonulease (RNase) and deoxyribonuclease (DNase) enzymes in pigeonpea (Cajanus cajan L.) and carpetweed (Trianthema portulacastrum L.) was studied in laboratory under controlled conditions. The activity of RNase and DNase enzymes increased progressively with passage of time in pigeonpea and carpetweed. The application of trifluralin and pendimethalin significantly decreased the activity of RNase and DNase enzymes during germination. The reduction in the activity significantly increased with the increase in the concentrations of herbicides. The pendimethalin was found to be more toxic in reducing the activity as compared to trifluralin in pigeonpea and carpetweed.
