CASE-STUDIES ON HIGH YIELDS OF PADDY RICE IN JIANGSU PROVINCE, CHINA .1. CHARACTERISTICS OF GRAIN PRODUCTION

Analysis of the characteristics of grain production of 965 gm-2 obtain ed by Shan You 63 (F1 hybrid rice) in 1991 was carried out. Absorption of nitrogen reached 21 gm-2 up to the time of heading, and a large ca pacity of grain yield (50,360 spikelets per m2) was obtained. Efficien cy of increase in spikelet number per m2 by absorbed nitrogen up to he ading was essentially the same as in west Japan. Mean Leaf Area Index 10 days before heading became exceptionally large (10.18). A large amo unt of translocation of accumulated assimilation products before headi ng improved the percentage of ripened grain. Increase in translocation of assimilated products stored in the culm and leaf before heading ma y remarkably increase yield in China.