Effect of establishment methods and weed-control measures on Broad leaf weeds, yield attributes and harvest index of wheat (Triticum aestivum L.)

Wheat (Triticum aestivum) is the world’s most widely cultivated food crop and in India it is second important staple food, rice being the first. The exhaustive rice wheat cropping system (RWCS) practiced with conventional tillage (CT) has resulted in lower marginal returns (Ladha et al., 2000), delay in wheat sowing and reduces wheat yield (Gangwar et al., 2005). Whereas zero tillage reduces production costs, saves water, increases soil organic matter, prevents soil erosion, mitigates greenhouse gases from the soil, improves air quality, protects wildlife habitat and biodiversity, improves production and ensures environmental safety (Gupta et al., 2002; Khan et al., 2004). Weeds cause yield reduction to the tune of 15 to 50 % or sometime more depending upon the weed density and weed flora (Jat et al., 2003). Weeds can be effectively controlled with the use of selective herbicides. As a result of this, different herbicides like clodinafop-propargyl and metsulfuron methyl have been tested. The actions of these herbicides on weeds have been tested under conventional method of wheat sowing but new techniques of establishment of wheat revealed different types of weed flora with different density of weeds and their management practices are also different to the conventional system.