花铃期水分亏缺对不同部位果枝棉铃发育及产量的影响

Effects of Water Deficit in Flowering and Boll-setting Period on Boll Development and Yield in Different Fruit Branches

【目的】研究花铃期水分亏缺对不同部位果枝棉铃大小(直径、长度、体积)、各组分干重(铃壳、纤维、棉籽)和产量的变化,以及水分亏缺处理与棉铃指标的关系,为机采棉花铃期供水不足时提供参考滴灌量。【方法】以新陆早50号和新陆早73号为材料,花铃期设3个滴灌量:2450 m^(3)/hm^(2)(CK)、2050 m^(3)/hm^(2)(D1)、1650 m^(3)/hm^(2)(D2),于花后17 d开始,每隔7 d分别取第2、第5和第7果枝的棉铃,共取5次,测定棉铃大小及各组分干重。【结果】2个品种不同部位果枝棉铃长度、直径和体积均在花后24 d达到最大值。在花后45 d,D1和D2处理中上部果枝棉铃直径与对照差异明显,新陆早50号中部和上部果枝棉铃直径分别降低2.92%~4%和2.21%~5.35%;新陆早73号分别降低2.66%~6.38%和2.77%~8.69%。2个品种棉铃各组分干重棉籽>纤维>铃壳,铃壳、棉纤维及棉籽重分别在花后24、38和38 d达到最大值。在花后45 d,2个品种D1和D2处理中上部果枝棉籽重与对照差异明显,新陆早50号中部和上部果枝棉籽重分别下降8.9%~20.71%和11.53%~20.73%;新陆早73号分别下降8.96%~16.24%和10.21%~17.06%。单株籽棉产量与棉籽重呈极显著的正相关。2个品种D2处理各部位果枝减产明显,新陆早50号下部、中部和上部果枝籽棉产量分别下降12.5%、13.48%和15.67%;新陆早73号分别下降12.69%、11.9%和18.21%。【结论】中上部果枝棉铃直径是影响棉铃干重的重要因素。水分亏缺不利于棉纤维和棉籽发育,中上部果枝棉籽受影响较大。D1处理与对照各部位果枝成铃数和籽棉产量差异不显著,2050 m^(3)/hm^(2)(D1)为应对花铃期供水不足时滴灌量。

【Objective】The changes of boll size(diameter,length,volume),dry weight of each component(boll shell,fiber,seed)and yield of fruit branches of different parts during flowering and boll-setting period were studied,and the relationship between water deficit treatment and boll index was also studied,so as to provide a reference for drip irrigation when water supply was insufficient in flowering and boll-setting period of machine harvesting.【Methods】Taking Xinluzao 50 and Xinluzao 73 as materials,3 drip irrigation quantities were set in flowering and boll-setting period:2,450 m^(3)/hm^(2)(CK),2,050 m^(3)/hm^(2)(D1)and 1650 m^(3)/hm^(2)(D2).Cotton bolls from the 2nd,5th and 7th fruit branches were taken every 7 days from 17 days after flowering,and the size and dry weight of each component were determined for a total of 5 times.【Results】The length,diameter and volume of boll of fruit branches in different parts of the two varieties reached their maximum at 24 d after flowering.The boll diameters of middle and upper fruit branches of Xinluzao 50 decreased by 2.92%-4%and 2.21%-5.35%,respectively,on 45 days after flowering,D1 and D2.Xinluzao 73 decreased by 2.66%-6.38%and 2.77%-8.69%,respectively.The dry weight of each component of boll of the two varieties was cotton seed>fiber>boll shell,and boll shell,cotton fiber and seed weight reached the maximum at 24,38 and 38 days after flowering,respectively.On the 45th day after flowering,the cotton seed weight of the middle and upper fruit branches of the two varieties treated with D1 and D2 was significantly different from that of the control group.The cotton seed weight of the middle and upper fruit branches of the two varieties decreased by 8.9%-20.71%and 11.53%-20.73%,respectively.Xinluzao 73 decreased by 8.96%-16.24%and 10.21%-17.06%,respectively.There was a significant positive correlation between seed yield and seed weight per plant.The yield of seed cotton on the lower,middle and upper branches of Xinluzao 50 decreased by 12.5%,13.48%and 15.67%,respectively.Xinluzao 73 fell by 12.69%,11.9%and 18.21%,respectively.【Conclusion】Boll diameter of middle and upper fruit branches is an important factor affecting boll dry weight.The water deficit was unfavorable to the development of cotton fiber and seed,and affected the seed of middle and upper fruit branches greatly.D1 processing and control branch into different parts of bell number and seed cotton yield difference was not significant,therefore,2,050 m^(3)/hm^(2)(D1)can be used as a response to water supply shortage reference drip irrigation during flowering and boll-setting period.