基于季节性降雨的双季稻生育后期干湿交替灌溉对稻谷产量及品质的影响

Effects of Dry-Wet Alternate Irrigation on Double Cropping Rice Yield and Quality during Late Development Stage under Seasonal Rain Condition

为明确依靠季节性降雨实现干湿交替灌溉对双季稻生育后期的影响,研究了双季稻齐穗后0、7、14和21d(对照)停止灌溉对叶绿素含量、干物质转化、产量及品质的影响。结果显示,早稻灌浆期降雨多且雨量大,齐穗后早停止灌溉延长干湿交替灌溉时间,可显著提高叶片、茎鞘干物质转化、穗粒数和结实率,叶绿素含量降低,无效分蘖成穗减少;与对照相比,齐穗后0d停止灌溉,实收产量提高16.0%,整精米率提高8.2%。晚稻灌浆期间降雨相对偏少,适期延迟停止灌溉,可提高叶片、茎鞘干物质转化、穗粒数、结实率、千粒重及整精米率;与对照相比,齐穗后7d停止灌溉,实收产量提高11.0%,整精米率提高6.1%;垩白度、垩白粒率及透明度随停止灌溉时间提前和干湿交替灌溉时间延长而增加,胶稠度以早稻齐穗后7d和14d、晚稻齐穗后14d停止灌溉最高,所有处理对双季稻米整体品质指标等级无影响。

To investigate the effects of dry-wet alternate irrigation on double cropping rice during the late development stage under seasonal rain condition, four different irrigation-stop times including the 0, 7 th, 14 th and 21 th(the control) day after rice full heading respectively were set in the field experiment, and the chlorophyll content, dry matter transport, yield, and quality were studied. The results showed that early rice had a lot of rainfall and heavy rainfall during the grain-filling stage. Stopping irrigation after full heading and prolonging the dry-wet alternate irrigation time could significantly improve the dry matter transport to leaves, stems and sheaths, significantly increase the number of ears and seed setting rate, and decrease chlorophyll content and panicles of ineffective tillering. Compared with the control, if the irrigation was stopped at 0 day after the ear was full, the harvested yield increased by 16.0%, and the heading rice rate increased by 8.2%. Based on light rainfall during the late rice grain filling stage, the time of irrigationstop should be delayed appropriately after full heading, which could increase leaf and stem dry matter transport, and the grains per panicle, seed setting rate, 1000-grain weight, and head rice rate. Compared with the control, stopping irrigation at 7 days after full heading, the harvested yield increased by 11.0%, and the heading rice rate increased by 6.1%. With the increase of dry-wet irrigation time after full heading, the chalkiness rate, chalkiness grain rate, and transparency increased and the adhesive strength reached the maximum under treatments of irrigation-stopping on 7 and 14 d after early rice full heading and 14 d after late rice full heading and all treatments had no effect on rice quality grade.