To indentify the key factors that are critical to the high grain yield of loosepanicle super hybrid rice, grain yield, yield components and grain-filling characteristics were compared between a loose-panicle (Zhunliangyou 527) and a compact-panicle (Y-liangyou 1) super hybrid rice by using data from three field experiments conducted in Hunan province, China during 2007 to 2011. Average grain yields were 9.56 t/ha for Zhunliangyou 527 and 9.44 t/hafor Y-liangyou 1, showing no significant difference between the two cultivars. Zhunliangyou 527 produced significantly less spikelets per panicle tha...
