An experiment to study the comparative effect of five herbicides 2, 4-D, Lasso, Vernam. Tenoran and Tok E-25 for the control of weeds in groundnut and their effect on pod yield was conducted for two Kharif seasons 1970–71 on variety M - 145 under irrigated conditions, at the Punjab Agricultural University Farm, Ludhiana. There was a marked reduction in the dry weight of weeds from 1354 kg/ha in unweeded control to only 180 kg/ha with ‘Lasso’ application. The pre-emergence spray of Lasso at the rate of 5 kg/ha also brought a significant improvement in plant characters. The plant height reduced from 16.60 cm to 13.55 cm, the number of secondary branches per plant increased from 8.58 to 11.33 (13%), and weight of mature pods per plant enhanced from 6.85 to 9 56 g. (39%). The ultimate yields of pods and straw per hectare showed a phenomenal increase of 29.8 and 30.3 per cent respectively with Lasso over the respective values of control. No adverse residual effect of Lasso was observed on the succeeding wheat crop.
