Maize Genomics and Genetics 2025, Vol.16, No.5, 267-275 http://cropscipublisher.com/index.php/mgg 268 even die (Queiroz et al., 2019; Xue et al., 2021). Corn is more afraid of early water shortage than many crops, so from sowing to jointing, the soil must be kept moist to allow the root system to grow well and the seedlings to be stronger. 2.2 Irrigation timing during tasseling and pollination During the tasseling and pollination stages, corn is more sensitive to water. If there is a lack of water at this time, it will directly affect the flowering and pollination processes, the fruiting rate will drop significantly, and ultimately lead to lower yields (Sah et al., 2020; Fawen et al., 2022). Many studies have pointed out that corn is most sensitive to water during the heading and flowering period, especially during the heading period, which requires more irrigation to prevent biomass reduction or bald ears. Watering should be done in time during heading and pollination to ensure that the filaments grow smoothly and the pollen is sufficiently active, thereby increasing the pollination success rate and fruiting rate. 2.3 Water control strategies during grain filling and maturity After entering the filling period, although the sensitivity of corn to water shortage is reduced, water should not be cut off at this time. Maintaining a certain soil moisture helps the grains continue to fill, grow fuller, and eventually have better yields. If there is too little water at this stage, the grain weight will decrease, and the total yield will also decrease, but the impact is not as great as when it was flowering. Many places use controlled irrigation or slightly water-deficient irrigation during this period, which can save water without seriously reducing production, provided that the key water supply has been guaranteed in the early stage (Meng et al., 2016). In addition, when it comes to maturity, attention should also be paid to seed moisture content. Studies have suggested that the seed moisture content should be kept at around 30% to 35% at harvest, so that the quality and vitality of the seeds are better, especially when encountering adversity, and the yield and quality can be maintained (Rahbari and Madandoust, 2024). 3. Effects of Irrigation Regulation on Growth Parameters 3.1 Changes in plant height and leaf area index (LAI) The amount of irrigation and the time of irrigation will directly affect the height and leaf area index (LAI) of corn. If enough water is applied at the right time, combined with appropriate fertilization, the plant height and leaf area of corn will grow better, the aboveground biomass will be more, and the final yield will be high (Qi et al., 2020; Chen et al., 2024). Methods such as alternating furrow irrigation or watering only part of the root zone, combined with appropriate nitrogen application, can significantly increase the leaf area index when corn is critical to growth, and can also allow more aboveground organisms to grow when mature. However, if there is not enough water during the vegetative growth period, or the drought period is too long, the corn will grow short, have fewer leaves, absorb less sunlight, and photosynthesis will also decrease (Comas et al., 2019). 3.2 Root development and soil moisture utilization The irrigation method will affect the growth and distribution of roots, and also affect the ability of corn to absorb water. Appropriately reducing irrigation, especially when partial root zone irrigation is used, can allow roots to grow deeper and wider. In this way, the roots can better absorb water and nutrients (Gheysari et al., 2017; Qi and Hu, 2022; Gao et al., 2024). For example, drip irrigation can not only make the roots longer, but also increase the proportion of coarse roots in the upper soil layer, which is closely related to high yields. If aerated irrigation is added, the root weight can be increased, and the beneficial bacteria in the soil will increase, which is more beneficial to both corn and soil (Yu et al., 2022). However, if the irrigation is too little, the roots will not grow well, especially they cannot grow deep, and the corn will not be able to absorb enough water from the deep soil (Jaswal and Sandal, 2024). 3.3 Biomass accumulation and dry matter distribution The biomass and dry matter distribution of corn are affected by the irrigation method. If irrigation is well managed and fertilized properly, not only will aboveground biomass increase, but dry matter and harvest index will also increase (Gheysari et al., 2017; Chen et al., 2024). In some growth periods that are not very sensitive, reducing
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