播期、密度和施氮量对旱种杂交稻产量和构成因子的影响

为筛选杂交稻旱种最佳的栽培方法，采用三因素三水平正交试验研究播期、密度和施氮量对旱育秧覆膜移栽杂交稻产量的影响，以及主要性状与产量的相关性分析。结果表明：随着播期从3月30日推后到4月20日，杂交稻旱种全生育期逐渐缩短，从155 d缩短到148 d；穗长、穗粒数、实粒数、结实率、千粒重与产量成正相关关系，相关程度为：结实率>实粒数>穗长>穗粒数>千粒重；主要性状对产量的直接通径正效应顺序为：穗长>结实率>有效穗数>千粒重>成穗率，直接通径负效应顺序为：株高>穗粒数。杂交稻旱种可通过提高结实率和穗长来增加产量，同时要控制株高。试验因素对产量的影响顺序为：播期>施氮量>密度，旱育秧覆膜旱移栽杂交稻最优高产栽培组合为：3月30日播种、每公倾90万基本苗和施用纯N 90 kg作分蘖肥。

Effects of Sowing Date,Density and Nitrogen Application on Yield and Component Factors of Dry Cultivation of Hybrid Rice

To screen the best dry land cultivation method of hybrid rice, a three factors and three levels orthogonal experiment was conducted to study the effects of sowing date, density, and nitrogen fertilizer application on the yield of transplanting hybrid rice with plastic film mulching after dry seedling cultivation, as well as the correlation analysis between main traits and yield. The results showed that as the sowing date was postponed from March 30th to April 20th, the total growth period of hybrid rice was shortened from 155 days to 148 days; there was a positive correlation between ear length, grain number per ear, actual grain number, seed setting rate, thousand grain weight, and yield, the correlation degree was as followed: seed setting rate>full grain number>ear length>grain number per ear>1000-grain weight; the direct path positive effects of main traits on yield was as followed: ear length>seed setting rate>effective ears>1000-grain weight>ear rate, while the negative effect of direct path was as followed: plant height>grain number per ear. Dry cultivation of hybrid rice could increase yield by increasing seed setting rate and panicle length, while controlling plant height. The order of influence of experimental factors on yield was as followed: sowing date>nitrogen application rate>density. The optimal high-yield cultivation combination for hybrid rice transplanted with film mulching in dry cultivation was: sowing on March 30th, 900000 basic seedlings per hectare, and tillering fertilizer of pure N 90 kg.