苗期涝渍对黄淮地区夏玉米生长和产量的影响

Effects of waterlogging during seedling stage on the growth and yield of summer maize in Huang-Huai Region

以玉米品种“浚单20”为试验材料,采用盆栽方式,在4叶期分别设置持续淹水（3、5和7 d）和持续渍水（5、10和15 d）处理,研究苗期涝渍对夏玉米生长及产量的影响。结果表明：苗期连续淹水3 d以上或渍水15 d的产量显著降低;与对照相比,淹水3~7 d,产量下降58.8%~69.8%（P〈0.05）;渍水15 d,产量下降47.8%（P〈0.05）;淹水3~5 d以及渍水15 d导致产量下降的主要原因是穗粒数减少,而淹水7 d减产是穗粒数减少和千粒重下降共同作用的结果;产量相对损失率与淹水天数的回归分析表明苗期淹水应控制在1 d以内;涝渍胁迫显著降低了地上部分干物质质量,其后续影响与胁迫方式、涝渍天数和生育期有关;淹水显著降低了拔节期及以后各生育期的地上干物质质量（P〈0.05）,而渍水对成熟期干物质重影响不显著（P〉0.05）;淹水处理可显著降低穗部占地上部分干物质的比例,淹水3~7 d,收获指数下降48.7%~64.1%（P〈0.05）。由此可判断,玉米产量随涝渍时间的延长而减少,且淹水胁迫对产量的影响大于渍水。

In this study, a pot experiment was conducted to investigate the effect of waterlogging during the seedling stage on the growth and grain yield of summer maize. Different treatments of surface waterlogging （for 3, 5 or 7 d） and subsurface waterlogging （for 5, 10 or 15 d） were in- cluded during the 4-leaf stage of summer maize cultivar Xnndan No. 20. The results showed that surface waterlogging at the seedling stage for 3 d or more and subsurface waterlogging for 15 d de- creased the grain yield significantly. Compared with the CK, surface waterlogging for 3-7 d de- creased maize yield by 58.8%-69.8% （P〈0.05） , while subsurface watedogging for 15 d de- creased maize yield by 47.8% （P〈0.05）. Yield reduction resulted from surface waterlogging for 3-5 d or subsurface waterlogging for 15 d was mainly due to the decline in grain number per spike, while surface waterlogging for 7 d would lead to the reduction in yield by decreasing the grain number per spike and the 1000-seed weight. Regression analysis of the yield loss rates and the surface watedogging durations indicated that effective measures should be taken to control wa- terlogging within 1 d at the seedling stage. The effect of waterlogging on the aboveground dry mat- ter weight of maize varied with the type and duration of waterlogging at different developmental stages. The aboveground dry matter weight after the jointing stage was significantly reduced due to surface waterlogging （P〈0.05）, while subsurface waterlogging did not affect significantly the aboveground dry matter weight at the maturity stage （P〉0.05）. Surface waterlogging for 3-7 d also affected the distribution of aboveground dry matter weizht,reducing the proportion cf drymatter in corncob and the harvest index by 48.7%-64.1% （P〈0.05）. The results indicated that the yield loss rate increased with the prolongation of waterlogging duration and the yield loss rate due to surface waterlogging was greater than that due to subsurface waterlogging.