Abstract: Under the studies of physiological-ecological laws on high-yielding culture of rice (Oryza saliva L.) in the plateau in 1983-1985, we had made a comparison between dry-matter production and partitioning after top dressing with nitrogenous fertilizer (urea) of rice grown at three localities, i. e., Yuanjiang (dry-heat river valley about 400 m altitude) , Kunming (warm-cool plateau lake-shore about 1900 m altitude) and Lijiang (cold-cool plateau area about 2400 m altitude) in Yunnan province. The treatments of top dressing, on the basis of 20 kg/mu urea applied as a basal dressing, were applied with 10 kg/mu urea at the young panicle differentiation, spikelet differentiation and reduction division stage (these stages of fertilizer application are briefly known as early, middle and lain car manuring) respectively.

Key words: Rice