Abstract: Using two hybrid rice combinations and two conventional varieties as materials, the experiment was carried out under different season in Hangzhou, China and Bangalore, India . When the Lilibao (a plant growth substance including GA 3 and PP 333 , meaning every grain will be filled) was applied at initial heading stage, the panicle neck length could be enhanced by Lilibao treatment, the senescence of the latest three leaves was delayed; apical dominance inter grain could be regulated, and resulted in increasing grain weight and yield.

Key words: rice, plant growth regulator, apical dominance, seed set

摘要： 以常规稻早籼中早1号、晚粳秀水11、杂交水稻Ⅱ优2070、EXPH1为材料在中国杭州和印度Bagalore不同熟制下进行施用粒粒饱的试验。于水稻初穗期施用粒粒饱（375 g/hm2），在水稻灌浆成熟过程中可以看到4种生物学效应：1) 增进抽穗，齐穗期提早2～3 d，并减轻“包颈”现象；2）促进开花，使花期集中，花期缩短约2 d；3) 延缓剑叶和其他功能叶片的衰老，可谓“青秆黄熟”；4) 调节“粒间顶端优势”，强势粒灌浆势进一步增强，弱势粒灌浆势提高，水稻产量增加。提高结实率和千粒重是水稻穗期施用粒粒饱增产的主要生物学基础。

关键词: 水稻, 植物生长调节剂, 顶端优势, 结实