Abstract: The results of comparison between two cultivation methods, "high-effective chemical regulation" and "conventional cultivation" of double-cropping rice in Lilin have been reported. With "high-effective chemical regulation" cultivation 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 is high which occupies up to 50-55% of total plant weight at maturity stage, the light penetration rate at late growth stage, the photosynthesis of functional leaves, and the transport rate of photoassimilate are high, grains fill well, harvest index is high. The yields of early rice and late rice are 8101. 5 and 8731. 5 kg/hm², respectively. There are 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 tillering stage, so dry matter accumulation is high(18. 8%) and nutrients absorption is more. Although the photosynthesis is low after heading, the duration of grain filling is long and this is beneficial to high yield.

Key words: double-cropping rice, dry matter production, high-yielding cultivation

摘要： 1996年醴陵基点双季稻超高产栽培技术途径比较试验结果表明，采用高效化控栽培法处理，前期生长稳健、个体发育好，中期群体适中、稻穗发育好，最大叶面积指数约7．5，光合产物积累多，孕穗期占成熟期的50%～55%，群体内部透光率高。后期功能叶光合能力强，光合产物运转率高，籽粒充实度好，经济系数高。早晚稻产量分别达到8101．5kg／hm²和8731．5kg／hm²，早晚稻子物质积累和养分吸收表现出明显的差异。早稻分蘖期气温偏低，干物质生产量小（为成熟期的13．3%），养分吸收总量少，抽穗后光合产物生产量大，高产潜力大。晚稻分蘖期气温高，干物质生产量大（为成熟期的18．8%），养分吸收总量多，抽穗后期光合能力弱，但晚稻灌浆结实的时间长，对高产形成有利。

关键词: 双季稻, 高产栽培, 干物质生产