Light interception, weed growth and productivity of irrigated wheat as influenced by crop geometry and weed control methods

The experiment was laid out in split-plot design with three replications by keeping combinations of three row directions (N-S, E-W and Bidirectional) and two row spacings (15 cm and 20 cm) plus broadcast sowing in main-plot and four weed control treatments (Unweeded check, Isoproturon 0.75 kg/ha, Isoproturon 1.50 kg/ha and hand weeding twice 30 and 60 DAS) in sub-plots. Bidirectional row orientation increased the light interception and crop growth rate with decreased weed growth rate. Consequently it increased the yield and yield attributes of wheat singificantly over the rest. Closesr row spacing (15cm) reduced the weed growth rate, increased the light interception, crop growth rate, yield and yield attributes over the wider row spacing of 20 cm. All the weed control treatments increased the yield, yield attributes and decreased the weed growth rate significantly over unweeded check. The per cent light interception upto top 50 per cent of total plant height was increased by weed control methods over unweeded check. But the light interception below the 50 per cent of total plant height with in the canopy was higher in unweeded plots. Among the weed control treatments, isoproturon 1.50 kg/ha resulted in significantly higher grain yield.