在全国13个点、19个品种、多播期试验基础上,本文对稻米垩白形成的气象生态基础进行了分析。结果表明水稻齐穗后15d内的温度状况是影响稻米垩白形成的主导因子。为了明确不同气象垩白大小(即气象条件引起稻米垩白面积的变化量)形成所要求的齐穗后 15d内的均温值,通过线性规划模型对3种稻米垩白大小情况给予了确定。并对我国稻区不同稻作制度下水稻气象垩白的分异情况进行了探讨。结果表明,从北向南,稻米气象垩白随水稻齐穗后15d内均温的变化由小到大,≤5％的稻区为四川盆地以北、淮河以北及云贵高原地区,5—10％的稻区为四川盆地、滇南以及淮南至沿江江南地区,10—20％(只为双季稻的早稻)的稻区为云贵高原以东长江以南地区。

On the basis of experiments with 19 rice varieties and many sowing datas in 13 placs of the whole country, the meteorologic ecological base of rice chalkiness formation has been analysed in this paper. Results show that the temperature condition in the 15 days after rice full heading stage is a leading factor affecting rice chalkiness. In order to know the average daily temperture of the 15 days after full heading that is demanded by the formation of different meteorologic chalkiness area (that is, the change of chalkiness area caused by meteorologic condition), the temperature demanded by 3 kinds of the miteroioogic chalkiness area is determined by a linear planning model as follows:meteorologic chalkiness area: < 5medium japanica:early indica:medium indica:The areal differentiation of meteorologic chalkiness in rice growing areas with different rice farming systems has been analysed by using the above indices. Results show that from north to south the rice meteorolgic chalkiness varies from small to big with the change of average daily temperature of the 15 days after rice full heading. The rice growing areas of the meteorologic chalkiness area of <5% include areas on the north of the Huaihe River, the Yungui plateau, and on the north of the Sichuan basin. Those of 5-10% include the Sichuan basin, southern Yunnan province and the areas from the south of the Huanhe River to the south of the Yangtze River along this river. Those of 10-20% (only the early rice of the double-cropping rice is concerned) include the areas on the east of the Yungui plateau and on the south of the Yangtze River.