Weed Dynamics and grain Yield of Wheat as Influenced by Methods of Sowing and Weed Management

Abstract

A field experiment was conducted in wheat during Rabi season of 2005-06 .on sandy loam soil at Crop Research Centre of Sardar Vallabh Bhai Patel University of Agriculture and Technology, Meerut. The experiment aimed at evaluating the effect of methods of sowing and weed management practices on weed and crop. In this investigation, two factor studies were planned. The first factor having, three methods of sowing, M1 Broadcast, M2 Line sowing at 22.5 em, M3 Cross sowing at 22.5 x 22.5 em and the second factor having, five methods of weed management practices like, W 1 Isoproturon 75 WP @ 0.75 kg a.i./ha post emergence, W2 2,4-D Na salt 80% @ 0.5 kg a.i./ha post emergence, W3 Isoproturon 75 WP @ 0.5 + 2,4-D Na salt @ 0.5 kg a.i./ha post emergence, W4 One hand weeding at 30 DAS and W5 weedy check were tested in randomized block design. Study revealed that cross sowing method proved superior over broadcast method of sowing followed by line sowing method in respect of weed population, weed dry weight, weed control efficiency, biological, and grain and straw yields. The maximum grain yield (44.02 q/ha) and straw yield (55.31q/ha) were recorded in cross sowing (22.5x22.5cm) followed by line sowing at 22.5 em apaf1:. Which gave 3.16 and 21.20 per cent higher grain yield than line sowing (M2) and broadcast sowing (M1) respectively. In respect of nitrogen, phosphorus and potash content and uptake, broadcast method of sowing provided its superiority over line and cross sowing. The highest B: C ratio of (1 .74) was recorded in cross sowing as compared to other methods of sowing. The lowest B: C ratio of (1.44) was recorded in broadcast methods of sowing. The results indicated that both mechanical and chemical methods of weed control were found superior over weedy check. The lowest weed population, lowest dry matter and highest weed control efficiency with highest grain yield of ( 4 7.11 q/ha) were recorded in treated plot with Isoproturon @ 0.5 kg a.i. + 2, 4-D Na salt 0.5 kg a.i./ha as post emergence and established its superiority significantly over post emergence application of Isoproturon@ 0.75 kg a.i/ha, 2,4-D Na salt@ 0.5 kg a.i./ha and one handweeding at 30 DAS. Significant difference was noted between mechanical weeding and application of Isoproturon @ 0. 75 kg a.i./ha as post-emergence in respect of grain yield. Similarly application oflsoproturon @ 0.5 kg a.i + 2, 4-D Na salt @ 0.5 kg a.i./ha has highest B: C ratio (1.96). All the weed management practices have highest benefit: cost ratio as compared to weedy check (1 :39). In respect of nitrogen, phosphorus and potash content in weeds and uptake by weeds all were recorded lowest Isoproturon @ 0.5 + 2, 4-D Na salt @ 0.5 kg a.i./ha treated plots.