<div><br></div><div><p style="font-size: medium; max-inline-size: 100%; margin-bottom: 0px; clear: both; min-height: 1em; cursor: text; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　黄河流域适期春播的棉花一般在８月下旬或９月上旬开始吐絮，至１０月底或１１月上旬，历时７０天左右。棉花吐絮后，营养生长渐趋停止，棉株体内积累的有机物质大量地由营养器官向生殖器官转移。生殖生长也渐趋缓慢。这个时期棉铃的生长成为营养供应中心，营养器官所含养分逐渐降低，而生殖器官中所含养分不断提高，氮、磷、钾养分从营养器官向生殖器官转移，以再利用的方式供给棉铃生长。</span></p><p style="font-size: medium; max-inline-size: 100%; margin-bottom: 0px; clear: both; min-height: 1em; cursor: text; overflow-wrap: break-word !important; outline: none 0px !important;"><br style="max-inline-size: 100%; margin: 0px; padding: 0px; overflow-wrap: break-word !important; outline: none 0px !important;"></p><p style="font-size: medium; max-inline-size: 100%; margin-bottom: 0px; clear: both; min-height: 1em; cursor: text; line-height: 1.75em; overflow-wrap: break-word !important; outline: none 0px !important;"><span style="max-inline-size: 100%; margin: 0px; padding: 0px; cursor: text; font-size: 15px; overflow-wrap: break-word !important; outline: none 0px !important;">　　高产棉花吐絮期要求的长势长相是，棉株下部吐絮，上部继续开花，到“处暑”以后断花。生长健壮的棉花，顶部果枝平伸，果枝长度为２０～３０厘米，有大蕾３～４个；吐絮初期叶面积系数２～２.５为宜，并缓慢下降，如叶面积过大，延迟吐絮；反之，易引起早衰，降低铃重。</span></p><p style="font-size: medium; max-inline-size: 100%; margin-bottom: 0px; clear: both; min-height: 1em; cursor: text; overflow-wrap: break-word !important; outline: none 0px !important;"><br style="max-inline-size: 100%; margin: 0px; padding: 0px; font-family: 微软雅黑, &quot;Microsoft YaHei&quot;, sans-serif; font-size: 17px; caret-color: rgb(255, 0, 0); overflow-wrap: break-word !important; outline: none 0px !important;"></p></div>