两系粳杂超稀播壮秧的分蘖成穗率初探

A Preliminary Study on the Ear-bearing Tiller Percentage of Sparsely-seeded Healthy Seedlings of Two-line Japonica Hybrid Rice

通过设置秧田每公顷１５０ｋｇ（Ａ）、２２５ｋｇ（Ｂ）、３００ｋｇ（Ｃ）３个播种量，对两系粳杂７０优双九作双晚种植的分蘖成穗特点进行定株观察，结果表明，以净秧田播量１５０ｋｇ／ｈｍ２，培育多蘖壮秧，每穴１粒种苗的栽植方式；以及提高栽插质量并加强肥水管理，适度控制中后期群体，是提高成穗率和产量、降低用种成本的有效途径。

The features of tillering and panicle formation from tillers of two-line japonica hybrid rice 70 You Shuang 9 were studied by the experiment of three seeding rates, i.e., 150, 225 and 300 kg/hm 2. The results showed that the percentages of panicles developed from the main culm, primary tillers and secondary tillers were 10.6%, 53.0% and 36.4%, respectively. In nodal position of tillers, most panicles were formed from the tillers of the 6th～9th nodes. In tillering growth stages, most panicles were formed within 20 days after transplanting. Significant advantages of tillering and panicle formation were found in the treatment of 150 kg/hm 2,in which the ear-bearing tiller percentages of population, primary tillers and secondary tillers were all higher than in the treatments of 225 and 300 kg/hm 2 seeding rates. It is concluded that sparse seeding can increase the ear-bearing tiller percentage and panicles per unit area, resulting in the increase of grain yield.