Studies on weed management in maize.
In field trials conducted on sandy loam at Dhaulakuan, Himachal Pradesh, during 1988-98, the effects were evaluated of pre-em. atrazine, alachlor or thiobencarb at 1 kg/ha, post-em. 2,4-DEE [2,4-D?] or atrazine at 1 kg, glyphosate (applied using a rope wick applicator with 1 part herbicide and 4 parts water), hand weeding once 20 d after sowing (DAS), and hand weeding twice 20 and 35 DAS for weed control in maize cv. Early Composite and Parvati. The most problematic weeds were Echinochloa crus-galli, E. colonum, Setaria glauca [Setaria pumila], Panicum dichotomiflorum, Ageratum conyzoides, Polygonum alatum, Cyperus rotundus, Commelina benghalensis, Cynodon dactylon, Sorghum halepense, Euphorbia heterophylla and Digitaria sanguinalis. All weed control treatments decreased weed DW from untreated control values of 215-270 g/m2 to 35-196 g, and increased maize grain yields from 3624 and 2100 kg/ha in 1988 and 1989, resp., to 4530-5851 and 2430-3766 kg, resp. Atrazine applied pre- and post-em. resulted in the greatest yields in 1988 and 1989, resp.