Management of diverse weed flora in maize under Kangra valley conditions of Himachal Pradesh

Twelve weed control treatments, viz. atrazine 1.0 kg/ha (2 days after sowing, DAS), metribuzin 0.25 kg/ha (2 DAS), oxyflourfen 0.15 kg/ha (2 DAS) alone and in integration with hoeing at 30 DAS, atrazine 1.0 kg/ha (2 DAS) followed by (fb) atrazine 0.5 kg/ha (30 DAS), atrazine 1.0 kg/ha + pendimethalin 0.5 kg/ha (2 DAS), intercropping of cowpea and mung bean, hand weeding thrice (15, 30 and 45 DAS) and weedy check were tested in maize during 2012 and 2013 under Kangra valley conditions of Himachal Pradesh. Herbicides alone, in combination with hoeing and sequential application significantly reduced the count and dry weight of weeds and increased number of cobs, 100-grain weight and grain yield of maize over the intercropping treatments. Maize grain yield was negatively associated with weed count (r=-0.819**) and weed dry weight (r =-0.791**) and positively correlated with cobs number (r = 0.950**), cob length (r = 0.879**) and 100-seed weight (r = 0.836**). With unit increase in weed count, the grain yield of maize decreased by 75.5 kg/ha. Un-checked weed growth reduced the grain yield of maize by 60.7%. Based on the results, metribuzin 0.250 kg/ha, atrazine 1.00 kg/ha, atrazine 1.0 kg/ha fb atrazine 0.5 kg/ha (30 DAS), oxyflourfen 0.15 kg/ha, atrazine 1.0 kg/ha + pendimethalin 0.5 kg/ha and metribuzin 0.25 kg/ha fb hoeing (30 DAS) were recommended for effective management of diverse weed flora in maize under Kangra valley conditions of Himachal Pradesh.