Field Crop 2025, Vol.8, No.6, 284-292 http://cropscipublisher.com/index.php/fc 286 sudden heavy rain or continuous overcast days, the vitality and yield potential of the seedlings will be discounted. In contrast, an obvious advantage of early sowing is more warm accumulation, faster seedling development and a more solid foundation. Figure 1 (a) Effect of adverse climatic conditions on the direct seeded rice crop. (b) Effect of adverse climatic conditions on the mechanically transplanted rice crop (Adopted from Jat et al., 2022) 3.2 Regulation of tillering, heading, and maturity by sowing date The number of tillers, the timing of heading and the time of maturity are actually all related to the sowing time. Earlier sowing usually prolongs the vegetative growth period, significantly increases tillers in the field, leads to more leaf growth, and accumulates more dry matter. However, once the sowing is late, the time is compressed, there are fewer tillers and fewer panicles, and the yield also decreases accordingly. Some farmers missed the sowing period and had to postpone sowing by a few days. As a result, the heading period happened to coincide with the cold weather, and the seed setting rate of spikelets dropped sharply, and the filling also became a problem (Zheng et al., 2020). Overall, the period from mid-May to early June is usually quite stable. Whether it's the tillering stage, the heading stage or the maturation stage, the temperature is well-coordinated. 3.3 Relationship between sowing date and meteorological factors (temperature/rainfall) Whether rice grows well or not, temperature and rainfall are two unavoidable factors, and these two are closely related to the sowing period. Sowing at the appropriate time not only ensures that the light can keep up, but also the temperature is just right. The photosynthetic efficiency is naturally high and the yield is more guaranteed. However, if the sowing is delayed until later, the heat accumulation will be insufficient, and the light is often
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