Effect of Planting Dates, Tillage and Residue Management on Weed Dynamics and Crop Productivity in Wheat Under Rice-wheat System

Abstract

Rice-wheat cropping system provides the staple grain supply for a large portion of the world's population and is critically important for global food security. In south Asia, this syste111 produces more than 30% of the rice and 42% of wheat and covers around 13.5 million hectare of cultivated land. Wheat (Triticum aestivum L.) is the most widely grown and consumed food crop and is the staple food for 35% of the world population. In India, wheat is not only constitutes the basic component of human diet and staple food but also contributes 14.4 % of the value added agriculture and 3.1 % to GOP. Tillage Practices, late sowing, poor crop establishment, lodging, water management and weed are some common factors behind yield stagnation. Wheat is generally has probletn of both, grassy weed and broad leaves weeds. These weeds are responsible for low productivity of wheat by sharing a greater part of nutrients, moisture, space and light with the crop. Keeping above facts in view, the present investigation was conducted for one year (20 13- 14) at Crop Research Centre, Central Soil Salinity Research Institute, Kamal (Haryana) during rabi season to work out weed dynamics and crop productivity in wheat under different tillage with or without residue managentent and planting dates. The field experiment consisting 12 treatment combinations (4 tillage and residue management practices viz.; conventional tillage, zero tillage, zero tillage with anchored residue and zero tillage with full residue; and 3 planting dates viz.; 25-0ctober, 5-November and 15-Novernber) laid out in Split Plot Design. with four replications. Zero tillage with full residue recorded significantly better growth parameters (except plant height and number of tillers) at all the growth stages, yield attributes, yield (Grain yield 5.08 t ha- 1) and (Straw yield 7.05 t ha-1 ) and economic returns of wheat over rest of the tillage management practices. In case of weed dynamics zero tillage with full residue recorded minimum weed density and biomass at all the growth stages over rest of the treatments while maximum was recorded under conventional tillage. Zero tillage with full residue significantly improved available phosphorous and potassium over rest of the treatments while, failed to affect available N and organic carbon in soil after harvest of the crop. Among the planting dates 25-0ctober sowing of wheat recorded maximum and significantly higher growth parameters (except total number of tillers), yield attributes, yield (Grain yield 4.91 t ha-1 ) and (Straw yield 7.17 t ha- 1 ) and economic returns over 15-November sowing. Early planting wheat recorded minimum weed density and biomass at all the growth stages compared to late planting. 25-0ctober sowing of wheat also improved available phosphorous and potassium over rest of the planting dates while, failed to affect available N and organic carbon. Therefore, a combination of Zero tillage with full residue and early planting of wheat (25-0ctoher), may be recommended for better weed management~ higher yield, higher productivity and net returns.