Comparison of Different Super-High-Yielding Cultivation Methods in Double-Cropping Rice

The results of comparison between two methods, high-effective chemical regulationand conventional cultivation of double-cropping rice in Lilin have been reported. With high-effective chemicalregulation methods, plants grow stably and healthily at early stage, the plant population is appropriateand panicles develop well, the maximum leaf area index (LAI) is about 7. 5, the photoassimilate accumulation ishigh which occupies up to 50～55% of total plant weight at maturity stage, the light penetration rate at lategrowth stage, the photosynthesis of functional leaves, and the transport rate of photoassimilate are high, grains fillwell, harvest index is high. The yields of early rice and late rice are 8101. 5 and 8731. 5 kg/hm2, respectively. Thereare obvious differences in dry matter accumulation and nutrients absorption between early rice and late rice. In early rice, the temperature is low, so dry matter accumulation and nutrients absorption are less. However, dry matter production is high after heading, so yield potential is high. In late rice,the temperature is high during tilleringstage,so dry matter accumulation is high(18. 8% ) and nutrients absorption is more. Although the photosynthesisis low after heading, the duration of grain filling is long and this is beneficial to high yield.