棉花后期“三喷”好对棉花生长后期，进行叶面根外追肥有显著的增产作用。（１）在８月下旬～９月上旬，用１０％～２０％的尿素溶液，每公顷喷６００～７５０ｋｇ，每隔５～７ｄ项１次，连喷２～３次，可使棉花叶片保持绿色，增强光合，防早衰，提高单产；（２）８月下旬... In the late cotton stage, “three spraying” had a significant stimulation effect on topdressing foliar fertilizer at the later stage of cotton growth. (1) In late August ~ early September, spray 600 ~ 750kg per hectare with 10% ~ 20% urea solution, once every 5 ~ 7d, and even spray 2 ~ 3 times to keep the cotton leaves Green, enhance photosynthesis, anti-premature senility, improve yields; (2) late August ...