Bio-efficacy of herbicides applied in cumin (Cuminum cyminum) and their carry over effects on succeeding pearlmillet (Pennisetum glaucum)

A field experiment was conducted during the winter seasons of 2010–11 and 2011–12 to study bio-efficacy of pendimethalin available in capsule suspension form (CS) and other recommended herbicides on the productivity of cumin (Cuminum cyminum L.) and their carry-over effects on the succeeding pearlmillet [Pennisetum glaucum (L) R. Br. Emend. Stuntz.]. Pre-emergence application of pendimethalin CS @ 484 g/ha + 1 hand-weeding controlled the weeds effectively in cumin and resulted in seed yield of 684 kg/ha, which was at par with weed-free check (701 kg/ha). Increase in the dose of pendimethalin CS from 484 to 580 and 580 to 677 g/ha did not influence seed yield of cumin but significantly suppressed plant count and biomass of succeeding pearlmillet. Application of pendimethalin liquid formulation @ 750 g/ha exhibited similar trend. Oxadiargyl and oxyfluorfen applied @ 50 g/ha + 1 hand-weeding at 30 days decreases the weed stand and weed dry matter, where the extent of control was at par with weed-free plots without any residual effect on succeeding pearlmillet. Post-emergence application of oxadiargyl @ 50 g/ha + 1 hand-weeding at 30 days recorded maximum seed yield (715 kg/ha), net return (58,400/ha) and benefit: cost ratio (4.08), with weed control efficiency of 99%, closely followed by oxyfluorfen 50 g/ha + 1 hand-weeding.