棉花不同生育期淹水历时对其生长状况和产量构成的影响

通过桶栽土培试验,分别在苗期(S)、蕾期(B)、花铃期(F)和吐絮期(T)进行淹水2、4、6、8、10 d的处理,淹水深度均为5 cm,并以全生育期不淹水为对照(CK),探索了黄淮地区夏季棉花不同生育期淹水历时对其生长状况和产量构成的影响。结果表明,在棉花苗期、蕾期和花铃期淹水6 d后,株高和叶面积开始显著小于CK(P0.05)。不同生育期淹水处理均会导致棉花株高、叶面积、果枝数、节数、铃数和单铃质量的下降,且淹水历时越长,下降幅度越大。淹水导致棉花减产最为严重的生育期为花铃期,其余依次为蕾期、苗期和吐絮期,4个生育期在淹水2~10 d条件下的平均减产率分别为28.0%、12.9%、7.3%和2.9%。在棉花苗期,当淹水不超过6 d时,如果排涝及时,其形态指标及产量构成均能在吐絮期恢复至与CK无显著差异水平。在棉花蕾期淹水关键期为4 d,而在花铃期即使淹水2 d也可导致其形态发育停滞,产量无法恢复至CK水平。

Effect of Timing and Duration of Flooding on Growth and Yield of Cotton

The impact of timing and duration of flooding on growth and yield of summer cotton in Huang-Huai Plain of China was investigated in this paper using pot experiment. The flooding was assumed to occur at seed-ling, squaring, flowering, or boll opening stages, lasting from 2 to10 days with the flooding represented by a 5 cm of water depth on the soil surface. Overall, there were 20 treatments. The results showed that flooding occurring at any stage led to a deterioration in both plant morphology and yield, and the reduction in the yield increased with the flooding duration. The impact of flooding timingon yield was in the order of boll-opening stage>seed-ling stage>squaring stage>flowering stage, reducing the average yield by 2.9％, 7.3％, 12.9％and 28.0％re-spectively, compared to the control (without flooding). Furthermore, plants suffering from a flooding less than six days at the seedling stage could recover morphologically at the boll-opening stage without resulting in significant yield loss if the soil can be timely drained. In contrast, a flooding occurring at the squaring stage for more than four days reduced yield. A flooding lasting even for two days at flowering stage inhibited morphological develop-ment and gave rise to yield loss compared with the CK. Therefore, an appropriate surface and subsurface drain-age of the water in flooding occurring at any growth stage is essential to mitigate damage to the yield.