Effect of new generation herbicides on weed parameters and seed yield of rice fallow black gram, Vigna mungo L

Afield experiment was conducted during the Rabi season of 2004 at Agricultural College and Research Institute, Madurai on sandy clay loam soil to study the effect of new generation herbicides and their rates on weed parameters and seed yield of rice fallow black gram, Vigna mungo L. The predominant weeds in the experimental field were grasses followed by broad leaved weeds and sedges. The results revealed that application of fenoxaprop-p-ethyl @ 75 g/ha was found to be very efficient in controlling the dominant grass weeds and found to be at par with fenoxaprop-p-ethyl @ 100 g/ha, cyhalofop butyl@ 100 g/haand 125 g/ha. Butalltheseherbicidesfailed to showtheir effecton sedgesand broad leaved weeds (BLWs). Imazethapyr @ 100 g/ha caused significant reduction in BLW density and dry matter production followed by imazethapyr @ 75 g/ha. The extent of control of dominant grass weeds was 95.55 with fenoxaprop-p-ethyl @ 100 g/ha, 95.51 with cyhalofop butyl @ 125 g/ha and 59.32 per cent with imazethapyr @ 100 g/ha. However maximum seed yield was recorded with fenoxaprop-p-ethyl @ 100 g/ha which was comparable with cyhalofop butyl @ 125 g/ha.