不同生育期淹涝对夏玉米叶片叶绿素及产量的影响

为了探明淹涝条件对夏玉米生理生态特性及产量的影响规律,在防雨棚下开展了夏玉米不同生育阶段淹涝的桶栽试验.在苗期、拔节期、抽雄吐丝期和灌浆期分别淹涝1,3,5,7,9d;以不淹水(适宜水分处理)为对照.结果表明,玉米株高和叶面积在苗期和拔节期受淹涝的影响最大,抽雄吐丝期次之,灌浆期淹涝的影响最小;叶绿素相对含量(SPAD...

Effects of waterlogging at different growth stages on leaf chlorophyll content and yield of summer maize

In order to find out the effects of waterlogging conditions on the physiological-ecological characteristics and yield of summer maize, the potted experiments of waterlogging stress in different growth stages of summer maize were carried out under a rainshelter. At the seedling stage, jointing stage, tasseling stage and grain-filling stage, the waterlogging durations were 1 d, 3 d, 5 d, 7 d, and 9 d, respectively, and no flooding(suitable soil moisture treatment)at the whole period was taken as control. The results showed that plant height and leaf area of maize were most affected by waterlogging at the seedling stage and jointing stage, followed by the tasseling stage, and waterlogging at the grain-filling stage had the least impact. Relative chlorophyll content(SPAD)and stomatal conductance(Gs)were most affected by waterlogging at jointing stage, followed by seedling stage and the least affected by grain-filling stage. The results also showed that SPAD and Gs had a certain recovery ability due to compensatory growth mechanisms, and the recovery ability of seedling stage was the strongest, jointing stage was the second, and grain-filling stage was the smallest with the later stage of waterlogging. Moreover, waterlogging at jointing stage had the greatest impact on ear traits and yield, followed by seedling stage, and grain-filling stage had the smallest influence. Finally, the mathematical model between the yield reduction rates of maize and waterlogging durations at different growth stages were established. According to the mathematical models, the yield reduction rate could be controlled within 10% as long as the waterlogging duration at seedling stage, jointing stage, tasseling stage and grain-filling did not exceed 1.5 d, 2.0 d, 1.5 d and 6.5 d, respectively, and could be more than 20% when the waterlogging days were exceeded 4 d, 5 d, 4 d and 10 d respectively. This study can provide data reference for the assessment of waterlogging disaster loss of summer maize and the establishment of farmland drainage projects.