黄淮海平原棉花形态发育和源库关系对土壤水分的响应

研究了黄淮海棉区不同土壤水分条件对棉花形态发育和源库的调节效应。试验结果表明,随着土壤含水量的增加,棉花的株高、营养枝载果量、植株总叶面积、果枝数、营养枝数和叶果比均有显著的提高,而营养枝倾角、果枝倾角和单位叶面积载果量则显著减小。土壤水分低于70%(相对土壤含水量,试验场地土壤田间持水量为24%,下同)时,果枝叶面积所占植株总叶面积的比例减小,主茎叶面积所占比例增加;土壤水分高于70%时,果枝叶面积和主茎叶面积所占比例同时下降,营养枝叶面积所占比例上升。花铃前期,70%土壤含水量的棉花籽棉干重/茎枝叶干重、铃和蕾量最大,分别达到了1.31,9.3个/株和53.7个/株。研究认为,黄淮海平原棉区,棉花蕾期至吐絮期的适宜土壤水分下限为70%,这样既改善了棉花植株的形态发育,又促进了源库关系的协调发展,提高了棉花产量。

Response of Cotton Morphological Development and Source-Sink Relationship to Soil Water Regime in Huanghuaihai Plain

Studies of the effects of different soil water regime on the cotton morphological development and source-sink relationship were carried out in cotton area of Huanghuaihai plain.The results showed that,with the increment of soil water content,the cotton plant height,fruit number(buds and bolls and flowers) of nutrition branches,plant leaf area,fruit branch number,nutrition branch number,and the ratio of leaf area/fruit all were improved,but the tilt angles of nutrition branches and fruit branches,and the fruit number per unit leaf area decreased significantly.When the soil relative water content was lower than 70%(the water-holding capacity of experiment field was 24%),the ratio of fruit branch leaf area/plant total leaf area(FBLA/PTLA) decreased,but the ratio of stem leaf area/plant total leaf area(SLA/PTLA) increased.When the soil relative water content was higher than 70%,the ratios of both FBLA/PTLA and SLA/PTLA decreased,but the ratio of nutrition branch leaf area/plant total leaf area(NBLA/PTLA) increased.During the earlier stage of flowers-bolls,under the treatment of 70% soil relative water content,the ratio of seed-cotton dry matter weight/stem and branch and leaf dry matter weight,boll and bud number were the biggest,which came up to 1.31,9.3/plant and 53.7/plant respectively.The studies confirmed that,in the cotton area of Huanghuaihai plain,the lower limitation of optimal soil water content of cotton field from bud stage to silking stage was 70%.In this way,the cotton morphological development was better,the coordination progress of source-sink relationship was improved,and the cotton yield was increased too.