栽插密度对天优华占辐射利用及产量的影响

Effects of Planting Density on Radiation Use and Grain Yield of Tianyou Huazhan

在大田条件下研究了不同栽插密度对超级杂交晚稻天优华占辐射利用和产量形成的影响。结果表明,在栽插密度为21.4万穴/hm2(株行距20.0 cm×23.3 cm)至37.5万穴/hm2(株行距13.3 cm×20.0 cm)范围内,天优华占产量随栽插密度减小呈先增大后减小的趋势,栽插密度主要通过有效穗影响产量。全生育期的平均辐射截获率(ALIR)、总辐射截获量(TIPAR)和辐射利用率(RUE)均随栽插密度的降低而逐渐减小。产量与ALIR、TIPAR及生育中、后期的群体辐射截获率(LIR)和有效辐射截获量(IPAR)均呈极显著正相关,与RUE呈显著正相关。天优华占栽插密度为30万穴/hm2(株行距16.7 cm×20.0 cm)时,整个生育期的平均LAI最大,且在生育中、后期叶面积指数适中,中、后期的群体LIR和IPAR以及后期的干物质积累量最大,产量构成因子间关系协调,在保证足量有效穗的基础上能够形成大穗、大粒,产量最高。

The effects of planting density were studied on the radiation use efficiency and grain yield of Tianyou Huazhan,a late super hybrid rice variety,in field conditions. The results showed that the grain yield of Tianyou Huazhan increased first and then decreased when the planting density decreased from high to low during the test range of 0. 375 million hills / hm2 with the spacing of 13. 33 cm × 20. 00 cm to 0. 214 million hills / hm2 with the spacing of 20. 00 cm × 23. 33 cm. The yield was affected by the planting density mainly via the number of effective panicles per hectare. With the planting density decreased,the average of light interception rate（ ALIR）,total interception of photosynthetic active radiation（ TIPAR） and radiation use efficiency（ RUE） decreased gradually.There existed a very significant positive correlation of the yield to ALIR,TIPAR and the light interception rate（ LIR） and interception of photosynthetic active radiation（ IPAR） of the middle and late stages,and a significant positive correlation of the yield to RUE. When the planting density was at 0. 300 million hills / hm2 with the spacing of 16. 67 cm × 20. 00 cm,Tianyou Huazhan had the highest averaged LAI of the whole growth period with an optimal LAI in the middle and late stages,the highest LIR and IPAR in the middle and late stages and the highest dry matter accumulation in the late stage,and had a good balance among the yield components with bigger panicle size and heavier grains on the basis of sufficient number of effective panicles,resulting in the highest grain yield among all tested planting densities.