孕穗期气象条件对水稻每穗总粒数和结实率的影响

通过分期播种试验，研究了气象条件变化对超级稻协优9308及常规稻绍糯119每穗总粒数和结实率的影响。结果表明：气温是影响每穗总粒数和结实率的主要气象因子，在抽穗前25—21d，每穗总粒数与气温呈“倒抛物线”关系，结实率与气温呈“抛物线”关系，每穗总粒数和结实率随气温变化表现出相反的变化趋势，是二者形成过程中对外界气象条件要求不同造成的。幼穗分化期处在气温为28．5～32℃的晴好天气下，可获得大穗和高结实率。

Influence of Meteorological Conditions During Spike Formation Stage on Number of Grain Per Spike and Setting Percentage of Rice

Based on the data of the interval sowing under the field conditions, the influence of meteorological conditions on the number of grain per spike and setting percentage of rice Xieyou 9308 and Shaonuo119 were studied. The result showed that the temperature was the major meteorological factor that affected the number of grain per spike and setting percentage of rice. From 25 to 21 days before heading period, a opposite quadratic regression could be used to describe the relationship between the number of grain per spike and temperature, while the setting percentage had a quadratic regression with the temperature. The number of grain per spike would increase and the setting percentage would be improved when the air temperature was between 28.5℃ and 32.0℃ during the young panicle differentiation period.