Irrigation at large trumpet stage: the stem and leaf of maize plant began to accelerate growth after jointing, and the leaf transpiration aggravated, and the female ear entered the differentiation stage of floret. Enhancing photosynthesis of leaves can promote the generation of aerial roots, reduce the degeneration of florets, shorten the intervals between male and female flowers, and facilitate the fertilization and fruiting.
Irrigation at heading and flowering stage: the heading and flowering of maize were in the midsummer, with the longest sunshine time, the highest temperature, the strongest transpiration of green leaves, and the maximum intensity of water requirement, which was the critical period of maize water requirement. Under less rainfall, combined with topdressing irrigation, soil moisture was maintained at 80% of field capacity, increased inter row humidity and increased pollen viability, which was beneficial to pollination, increasing seed setting rate, increasing photosynthesis intensity, and transferring more nutrients to ears.
Grain filling stage irrigation: when corn is pollinated, it will enter the stage of grain formation and filling. When rainfall is too small, irrigation should be timely to keep soil moisture at 70%~75% of field capacity, prevent premature senescence and prolong leaf functional period. If this period of water is insufficient, the photosynthesis of the leaves will be weakened, the organic matter synthesis will decrease, the grain filling rate will be affected, and the grain volume will shrink and the savings capacity will be reduced. Serious water scarcity will cause grain nutrient and water to reverse and reverse, resulting in a serious reduction of corn yield. In this period, it is generally better to use 3~4 water for irrigation, and 780~825 cubic meters of water per hectare can increase corn yield by 25.36%.
Source: China agriculture news network - Farmers Daily