Weed dynamics, productivity and economics of maize (Zea mays) as affected by integrated weed management under rainfed condition

A field experiment was conducted during rainy season of 2005 and 2006 under rainfed condition at Faizabad on a silty-loam soil to find out the most effective weed control measure in maize (Zea mays L.). Pre-emergence application of alachlor (2.0 kg/ha), pendimethalin (1.0 kg/ha) and atrazine (1.0 kg/ha) alone and in combination with one hand-weeding (30 DAS), two hand-weedings (20 and 40 DAS), smother crop (blackgram and Dhaincha) and earthing-up were compared with weed-free and weedy check treatments. Two hand-weedings at 20 and 40 DAS proved most effective (weed-control efficiency, WCE 60.74 and 71.78%) followed by alachlor 2.0 kg/ha + hand-weeding at 30 DAS (WCE 55.86 and 68.31%) and they reduced the weed density and weed biomass significantly, which in turn increased yield compared with weedy check. The highest grain yield of 3.70 and 3.63 t/ha was recorded under weed-free treatment during 2005 and 2006 respectively, which was on a par with two hand-weedings at 20 and 40 DAS. The highest net returns were obtained under weed-free treatment, but highest benefit: cost ratio was recorded under earthing-up and two hand-weedings.