Waterlogging at seedling and jointing stages inhibits growth and development, reduces yield in summer maize

An experiment about different waterlogging duration (2, 4, 6, 8, 10 d) which was set up at seedling, jointing, tasseling and grain-filling stage, respectively was conducted in lysimeters with a rain shelter, and the effects of waterlogging timing and duration on the growth, development and yield characters of summer maize were analyzed. The results showed that the influence of waterlogging on plant height reduced with the postponement of waterlogging timing. Waterlogging occurring at the seedling stage had the greatest impact on plant height, followed by the jointing stage. The tasseling stage imposed a little effect, and plant height decreased when the waterlogging duration was increased, but waterlogging occurring at the grain-filling stage imposed no significant effect on the plant height. After waterlogging at the seedling stage, the difference in plant height between waterlogged treatments and the control (CK) gradually reduced with the advance of the growing process because the early stage of maize had a strong ability of compensatory growth. The difference in that during the jointing stage was still great at the grain-filling stage due to the weak compensatory growth. The changing trend of the leaf area index (LAI) in various waterlogged treatments was similar to the plant height. and grain-filling stages caused plant height to be averagely decreased by 5.49%-45.26%, 2.38%-35.62%, 1.60%-8.23% and 0.63%-5.15% respectively. It also made LAI to be reduced by an average of 17.36%-62.42%, 14.81%-46.56%, 4.40%-17.34% and 1.97%-15.39% respectively. Waterlogging had an obvious influence on the process of growth and development in summer maize, especially at the early growing stage. waterlogging at the seedling stage resulted in the greatest impact on growth process of summer maize, followed by the jointing stage, waterlogging at tasseling stage had little effect, and waterlogging at grain-filling stage did not affect the growth process. In addition, waterlogging occurring at any growing stage, resulted in ear length, seed-producing percentage, grain weight per ear, grain number per ear, 100-grain weight and grain yield of summer maize decreasing with increased waterlogging duration. As waterlogging occurring at the seedling stage, jointing stage, tasseling stage and grain-filling stages, the grain yield of summer maize was reduced by 17.98%-54.97%, 9.12%-100%, 2.58%-28.63% and 5.93%-20.28%, respectively. When the waterlogging duration at the seedling stage, jointing stage, tasseling stage and grain-filling stage reached 2, 4, 6, and 4 d respectively, the waterlogging would cause a significant decline in grain yield with the reduction rate of 17.98%, 21.34%, 12.99% and 13.52% separately. Therefore, the seedling stage and jointing stage are a critical period of waterlogging for summer corn, and waterlogging should be avoided during that stage. This study will provide a theoretical basis for the rational design of a drainage scheme in summer maize farmland, loss assessment of a flood disaster, and improvement of disaster prevention and mitigation.