稻胡麻叶斑病菌孢子飞散规律的研究

在1962—63年的盆栽秧苗捕捉孢子的結果中发現了:(1)空中孢子飞散数量,白天极显著的比晚间多;(2)晴天极显著的比雨天多,降雨量之大小与孢子飞散的函数关系为指数曲綫方程式:S=a·P~(-b)。当降雨量在4公厘以下时,雨时与孢子飞散无一定关系;当降雨量在4公厘以上时,两者成負相关,其迴归方程式为:logS=a—blog T;(3)孢子飞散与田間病害消长的函数关系为:logD=a blog S。

STUDIES ON THE SPORE DISPERSAL OF HELMINTHOSPORIUM ORYZAE

According to the results of a two-year observation, using potted rice seedlings as biological spore trap, it was found that more Helminthosporium spores released in the day than in the night, and more spores were collected on a fine-day than on a rainy one. The dispersal of air-borne spores is correlated with the precipitation, this correlation is to be expressed as the following: S=a·p^-b. The relationship between the dispersal of air-borne spores and the times of rainfall is to be discribed by the following equation: Log S=a-b Log T. The logarithm of the diseases in fields is proportional to the logarithm of the dispersal of air-borne spores, and obeys the relation: Log D=a-b Log S. S is the amount of air-borne spores, P is precipitation, T is times of rainfall and D is index of disease.