Effects of Waterlogging on Photosynthetic Characteristics and Yield of Summer Peanut

Abstract

Yield of summer peanut is often reduced due to waterlogging caused by excessive rainfall in flood season. Exploring the effects of waterlogging duration under different cultivation pattern on photosynthetic characteristics and yield of peanut can provide scientific and technological support for dynamic monitoring, evaluation of waterlogging process, disaster prevention and mitigation. Field experiment is carried out in main peanut production area with clay soil. Peanut variety Yuhua 22 is used in field experiment under flat and ridge cultivation patterns. The yield formation process of peanut is divided into three stages: Early, middle and late, and four irrigation treatments (3 days, 5 days, 7 days and 9 days) are designed in these stages. In flat pattern, the depth of water in field is no less than 2 cm during irrigation, and the daily irrigation amount of ridged plots is consistent with that of flat plots. The results show that under the same irrigation amount, the waterlogging lasting days of ridge pattern are reduced by 1 to 5 days, and the flooding days are reduced by 3 to 5 days. The waterlogging duration is 4 to 5 days in 3 days irrigation treatment. Chlorophyll content and net photosynthetic rate show positive effects, resulting in the increase of dry matter accumulation in stems and leaves. The effects of waterlogging in all stages increase with waterlogging duration, but it has little effect in late stage because of the slow growth of peanut itself. For the 100-seed weight, the effects of heavy waterlogging are most significant in the middle period, followed by the early period, and then the late period. While for other factors, the effects are most significant in the early period. The waterlogging duration in all treatments is between 4 days and 16 days. The effects range from 1.3% to 64.2% on photosynthetic parameters and from 0.9% to -44.9% on biomass and yield. Compared with flat pattern, ridge pattern has less effects due to the decrease of waterlogging duration. The peanut yield loss of each treatment ranges from 3.4% to 11.6% in early stage, and from 1.2% to 6.9% in middle stage. The experiments take possible waterlogging lasting days in peanut production and two different cultivation patterns (flat and ridge) into consideration reasonably. The results are of great significance to enhance the capacity of disaster prevention and mitigation in peanut production.