杂交晚稻秧田分蘖习性及促蘖措施

Studies on the Tillering Habit in Seedling Bed of Late Hybrid Rice and the Measure to Promote Tillering

杂交水稻根系强大，晚稻育秧期间温度高，秧田播种较稳，为秧田阶段的分蘖创造好的条件，可使秧田分蘖产量占总产量的２０％～３０％。通过多年对分蘖习性的观察，认为正确促控分蘖是杂交晚稻增加产量降低消耗的中心措施。

Late hybrid rice starts tillering 8-10 days after seeding (DAS), tillering is fastest in 15-20 DAS, and 30 DAS reaches the number of maximum tillers. The contribution of the tillers in the seedling nursery to the grain yield is 20. 8%-30. 9%. On the basis of the tillering habit of late hybrid rice,it is recommended to apply nitrogen fertilizer 7 DAS in order that a tillering peak is formed in the seedling bed, ing young vigorous seedlings with more tillers at low nodal position; and 5 days before transplanting, apply nitrogen fertilizer to produce more young white roots 2-3cm long, making the seedlings easily pulled and reducing damage by pulling, thus favouring survival of the tillers and formation of panicles. Futhermore, for late hybrid rice,a series of indeces for vigorous seedling with various seedling ages and an experiential formula, i. e. seedling age(day) + seeding rate(jin/mu, 1 jin= 0.5kg) ≤55 are also put forword.