国家子棉生产不断增长的问题及质量的改善同棉花的早熟性最紧密地联系着。尤其是在不利的年份同生长期内有效积温低时,提高早熟性更重要。由于人类多世纪的努力,已创造了很多有经济价值的棉花类型。这一最有价值的技术作物分布在从南纬35度(澳大利亚)到北纬44度(苏联)的地区。采用经典的和其他某些方法(杂交、外界环境 The growing problem of the country’s sub-cotton production and its improvement in quality are most closely linked to the precocity of cotton. Especially in the unfavorable year with the effective growth temperature is low, it is more important to improve the precocity. Thanks to human efforts over the centuries, many types of cotton with economic value have been created. The most valuable technical crop is located in the area from 35 degrees south (Australia) to 44 degrees north latitude (the Soviet Union). Use classic and some other methods (hybridization, external environment