Effect of planting pattern and weed-control methods on weed growth and performance of wheat (Triticum aestivum)

A field experiment was conducted during 2000–01 and 2001–02 at Pusa, Bihar to study weed growth, nutrient removal, weed-control efficiency and yield, and nutrient uptake by wheat (Triticum aestivum L. emend. Fiori & Paol.) as influenced by planting pattern [criss-cross (20 cm × 20 cm), normal line sowing (20 cm) and broadcast] as well as weed-control treatment [weedy check, hand-weeding (30 days after sowing), isoproturon @ 0.75 kg/ha (pre-emergence), sulfosulfuron @ 33.3 g/ha (post-emergence) and 2,4-D Na salt @ 0.80 kg/ha (post-emergence)]. Criss-cross sowing significantly reduced the weed biomass and hence lowered the nutrient depletion by weeds, ultimately resulting in higher nutrient uptake and yield of wheat crop. Normal line sowing and broadcasting methods recorded 7.29 and 19.93% less grain yield than criss-cross sowing. Amongst the weed-control treatments, post-emergence application of sulfosulfuron was found on a par with hand weeding treatment for controlling weeds and producing grain yield of wheat. The different weed-control measures led to 119.5–139.0, 123.2–141.3 and 120.4–138.5% increase in N, P and K uptake by wheat respectively, and 59.9–74.6, 60.2–75.0 and 60.0–75.5% reduction in the depletion by weeds over the weedy check.