Abstract

The present experiment was conducted to assess the effect of  herbicides on growth and biochemical behaviour of wheat crop during the rabi season 2009-10 at Instructional farm of Narendra Deva University of Agriculture and Technology, Kumarganj, Faizabad, Uttar Pradesh, India. The experiment comprised one wheat variety HUW-468 and four herbicides treatments, isoproturon, phenoxaprop-p-ethyl, sulfosulfuron and one untreated check. All the plots were kept free of weeds manually throughout the growing season. Plant height, number of tillers plant^-1 and leaf area index of wheat were reduced under herbicides treatments with respect to untreated check. Reduction in above growth characters was lowest with sulfosulfuron followed by phenoxaprop-p-ethyl and isoproturon. Although, the difference between untreated check and herbicides for grain yield, biological yield and harvest index was non significant but slightly lower values for above traits were observed with herbicides as compared to untreated check. Nitrate reductase, nitrite reductase activity and protein content in leaves were also reduced due to herbicides relative to untreated check, however sulfosulfuron caused least reduction. Catalase and peroxidase activities in leaves were significantly increased due to herbicides over untreated check; minimum increase was observed with sulfosulfuron, while isoproturon had maximum increase. Thus, it may be concluded that among herbicides used in the experiment, sulfosulfuron is the safest for weed control in wheat as it showed least adverse effect on growth, yield and biochemical parameters of crop.

Key words: Triticum aestivum L., herbicides, isoproturon, phenoxaprop-p-ethyl, sulfosulfuron, nitrate reductase, nitrite reductase, catalase, peroxidase.