Effects of Duration of Waterlogging at Different Growth Stages on Grain Growth of Summer Maize (Zea mays L.) Under Field Conditions

A field experiment was performed to study the effects of waterlogging for different durations (3 and 6 days) on grain filling and endosperm cell proliferation of summer maize hybrids DengHai605 (DH605) and ZhengDan958 (ZD958) at the third leaf stage (V3), the sixth leaf stage (V6) and the 10th day after the tasselling stage (10VT). Results showed that waterlogging damages on grain filling and endosperm cell proliferation varied with growth stage and duration of waterlogging. The most significant effect of waterlogging was observed at V3, followed by V6 and 10VT. Endosperm cell content, average endosperm cell proliferation rate, grain weight and grain-filling rate were reduced significantly with increasing waterlogging durations, with the most significant (P<0.05) reduction in V3-6 with a decrease of 37.1%, 51.9%, 13.6% and 12.1% for DH605, and 27.3%, 51.1%, 17.4% and 14.3% for ZD958, respectively. Waterlogging damages on grain filling and endosperm cell proliferation resulted in a significant reduction in grain yield. Waterlogging at V3 had the most yield reduction, followed by V6 and 10VT. Yield reduction after waterlogging for 6days at different stage was about twice as much as that after waterlogging for 3days. Clearly, the most significant inhibition of grain growth for waterlogging was observed at V3, followed by V6 and 10VT. The inhibition was enhanced significantly with increasing waterlogging durations. Endosperm cell number and grain weight was decreased by 8.3-24.1% and 1.2-10.8% after waterlogging for 3days, while decreased by 12.9-32.2% and 4.6-14.7% after waterlogging for 6days, compared to CK.