Effects of Different Fertilizer Rate on Population Quality and Yield Formation of Super Hybrid Rice

Field experiments with Super hybrid rice cultivars(LY-293 and ZLY-527) were conducted in Changsha city in 2004-2005 by using split-plot design with 4 replicates.Three fertilizing treatments,i.e.,the low rate(N 135kg/hm2 + P 29.7kg/hm2 + K 112.1kg/hm2),the middle rate(N 180kg/hm2 + P 39.6kg/hm2 + K 149.4kg/hm2) and the high rate(N 225kg/hm2 + P 49.5kg/hm2 + K 186.8kg/hm2) were experimented to study yield、yield formation、dry matter accumulation and partition and some physiology indexes.The main results were summarized as follows:(1)there were significant differences of the yield and effective panicle number,spikelets number per panicle and grain filling percentage between two years,but not among the fertilizer treatments;(2)there were significantly positive correlation between the total dry matter production and the grain yield in super hybrid rice,and the correlation coefficient of ZLY-527 and LY-293 is 0.9377** and 0.8630**,respectively;(3) some physiology indexes were different between two cultivars of which LY-293 performed as stronger tillering ability,finer Leaf Area Index,lower productive tiller percentage,high dry matter production during the early and mid-growth periods,and ZLY-527 had higher yielding performance characteristics with more stable tillering growth at the early growth stage and higher tiller productive percentage at the mid-growth stage and high dry matter production during the late growth period.