打顶、化控与磷肥耦合对长绒棉产量结构、蕾铃形成及脱落的影响

Effect of Topping,chem-Control and Phosphorus Fertilization on the Yield Components,Forming and Shedding of Buds and Bolls of Long Fiber Cotton

采用田间小区试验,首次系统地研究了打顶、化控、磷肥耦合对长绒棉产量构成、蕾铃形成及脱落的影响。结果表明,打顶、化控和磷肥对棉花产量表现出负耦合效应。打顶、化控和磷肥单独使用对长绒棉有增产作用,而它们配合使用表现出减产作用。低磷不化控情况下,打顶可使棉花蕾铃脱落率显著降低,从而使单株有效结铃数增加。低磷不打顶情况下,化控同样能降低长绒棉的蕾铃脱落率,但化控也降低了现蕾数,从而使其单株结铃数没有显著增加。在不打顶不化控情况下,增施磷肥可显著提高长绒棉的现蕾数,使单株结铃数提高。在化控或高磷情况下打顶都会使长绒棉的现蕾数明显下降,导致单株有效结铃数降低。

Based on field experiments, effect of topping, chem- controlling and phosphorus fertilization on the yield components, forming and shedding of buds and bolls of long fiber cotton was studied. The main results were as follows： coupling effect of topping, chem- controlling and phosphorus fertilization on the boll weight, boll number and yield of cotton was negative. Only - using topping, chem - control and phosphorus fertilization increase the long fiber cotton yield, while cooperation - using them could decrease long fiber cotton yield. Since topping could decrease markedly shedding rates of cotton under low P level and non - them- controlling condition, number of available cotton bolls was greatly increased. Under low P level and non - topping condition, chemical controlling decreased markedly the shedding rate, and decreased buds of cotton, thereby number of available cotton bolls was not increased markedly. When adding P fertilizer increased buds of cotton under non - topping and non - chem - controlling condition, number of available cotton bolls was thereby increased. Since topping decreased number of cotton buds under chem - controlling condition or high P level, number of available cotton bolls were thereby decreased.