Effect of isoproturon, sowing method and seed rate on weeds and yield of wheat (Triticum aestivum)

A field experiment was conducted during winter season of 1989-90 and 1990-91 to study the effect of isoproturon, sowing method and seed rate on weed management in 'WH 423' wheat (Triticum aestivum L. emend Fiori & Paol.). Cross-row sowing significantly reduced the dry weight of weeds both in the weedy control and plots treated with isoproturon @ 0.75 kg/ha. In the weedy control the dry weight of weeds at  90 days after sowing decreased from 134.9 g/m 2 at 100 kg seed/ha to 96.1 g/m 2 at 175 kg seed/ha. Based on the average of seed rate and weed-control treatments, cross-row sowing increased the average wheat yield by 0.44 tonne/ha compared with line sowing. Seed@ 100 and 175 kg/ha gave an average wheat Yield of 4.57 and 5.44 tonnes/ha respectively. Isoproturon@ 0.75 kg/ha applied 20 days after sowing gave 52%  more average grain yield of wheat than the weedy control.