利用杂种优势增加作物产量,是现代农业科学技术的重大成就之一。过去,在棉花上曾进行陆地棉和海岛棉种间杂种优势的利用,可增产百分之二十以上,纤维品质优良。但要生产大量杂种种子,沒有特殊的技术是困难的,为此,必须利用“雄性不育系”或采取“化学杀雄”的方法。目前,棉花的化学杀雄,可以采用“二氯丙酸”和“二氯丙酸钠”等化学药剂,一 Using heterosis to increase crop yields is one of the major achievements of modern agricultural science and technology. In the past, the use of interspecific heterosis between upland cotton and island cotton on cotton has been increased by more than 20% and fiber quality has been improved. However, to produce large numbers of hybrid seeds, there is no special technology is difficult, therefore, we must use “male sterile” or adopt “chemical kill male” method. At present, cotton chemical kill male, you can use “Dichloropropionic acid” and “sodium dichloropropionate” and other chemicals, a