1986～1987年为我国夏棉品种第四轮区域试验,分长江和黄河流域两个棉区进行。黄河流域棉区设试点15个,参试品种(系)3个,两年参加汇总的试点为25个。长江流域中下游棉区设试点5个,两年参加汇总试 1986 ~ 1987 for the fourth round of regional trials of summer varieties of cotton, the Yangtze River and the Yellow River two cotton areas. There are 15 pilots in the cotton area of ​​the Yellow River Basin, 3 varieties of test varieties (lines), and 25 pilots in two years for the compilation. The middle and lower reaches of the Yangtze River cotton area pilot 5, two years to participate in the summary of the trial