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保加利亚棉花生产与优良的棉花早熟品种密切相关。棉花原产热带,是喜温作物,在地球上的分布从北纬45度(罗马尼亚、中国)至南纬35度(澳大利亚),通常称为棉花带。对于棉花的早熟性问题,按A.Low(1972)的意见,凡是总活动积温低于4500℃,均面临棉花早熟性问题。保加利亚位于北纬41°～44°之间,总活动积温只有3528℃,因此,棉花早熟是棉花生产首要问题,只有棉花早熟,才能保证棉花高产、稳产。才有成功实行机械化和棉地轮作更新的可能性,苏联、美国、埃及等国家最大棉花育种中心,均在从事棉花早熟品种的选育。
Bulgaria’s cotton production is closely linked to the fine varieties of precocious cotton. Native to the tropics, cotton is a thermophilic crop that spreads from 45 degrees north latitude (Romania, China) to 35 degrees south latitude (Australia) on earth, commonly referred to as a cotton belt. For the problem of cotton precocity, according to A. Low (1972), all accumulated activity temperatures below 4500 ° C are subject to cotton precocity. Bulgaria is located between latitudes 41 ° ~ 44 ° and the accumulated accumulated temperature is only 3528 ° C. Therefore, precocious cotton is the most important issue in cotton production. Only when cotton is precocious can it ensure high yield and stable cotton yield. Only the successful implementation of the mechanization and cotton rotation possibilities for the rotation, the Soviet Union, the United States, Egypt and other countries the largest cotton breeding center, are engaged in breeding of precocious varieties of cotton.