Investigation the effects of nitrogen, cover crop and tillage date on weed density and yield cotton

This experiment was carried out for 2 years in Cotton Research Station of Karkendeh and Hashabad region in factorial–split plot using randomized complete block design with 3 factors in 4 replications. The purpose of evaluation was effects of tillage date, various levels of nitrogen fertilizer and plant date of cotton with cover crop on yield, yield components and weed density of Golestan cotton verity. Two tillage date were as first factors, two various levels of nitrogen fertilizer were as second factors and four plant date cotton with cover crop were as sub-factors. Composite variance analysis of traits showed that both region and tillage date had no effect on yield, yield components and weed density. The stage plant seedlings did not properly covered in cotton rows. Most weeds of cotton were observed in cultivation vetch after emergence of cotton treatment. In the second stage, vetch was covered among cotton rows and the highest number of weeds was observed in cotton treatment. The lowest number of weeds was related to cultivation vetch before emergence of cotton treatment and this treatment, in addition to having the lowest yield had the lowest weeds.