Abstract

A field experiment was conducted during summer season of 2010 and 2011 at district seed farm, Kalyani under Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, to find out the effect of different post emergence herbicides on summer growing groundnut in new alluvial zone of West Bengal. All the herbicidal treatments as well as weed free check significantly increased the yield and yield attributing characters of groundnut and also reduce the weed population as well as weed biomass production as compared to un-weeded control. Post emergence application of quizalofop Ethyl at 100g a.i./ha was found better to control the weeds as compared to imizathapyr. Among the post-emergence herbicidal treatments pod yield, haulm yield and yield attributes of groundnut was found maximum with the treatment received post emergence application of quizalofop Ethyl at 100 g a.i. /ha. Among all the herbicidal treatments best results was obtained with pre-emergence application of pendimethalin at 1.0 Kg a.i./ ha along with one hand weeding and recorded highest pod yield (2675 Kg/ha), haulm yield (3123 Kg/ha), number of pods/plant (17.3), shelling % (71.3) and SMK % (91.4). This might be due to application of pendimethalin as a pre emergence, suppresses the weed growth at early stage of the crop as a result of better crop stand. Practices of weed control by chemical and /or mechanical gave the significantly better pod yield of groundnut as compared to un-weeded control and pod yield of groundnut was decreased even up to 26 to 47% in un-weeded condition. Among the herbicidal treatments maximum gross return (Rs.80550), net return (Rs.55937) and B:C ratio (3.27) were recorded in the treatment received pre-emergence application of pendimethalin at 1.0 Kg a.i./ ha along with one hand weeding.

Key words: Groundnut, herbicide, pre-emergence, post-emergence, yield, economics.