雨滴によるいもち病菌浮游胞子の落下

抄録

The Piricularia oryzae-spore content of air has been studied by use of the HIRST automatic volumetric suction trap and rotation sampler during the rice blast outbreak every hour by a day. The number of sampled spore are diminished on a rainy day as compared with fine day. Especially, the diminution by rain are markable at begining of rain fall and a heavy rain.
In a severe outbreak field of rice blast, we have collected rain water and counted. the number of Piricularia oryzae-spores brought down by rain drops. In the period of maximum outbreak of leaf blast, we found that 1.5mm of rain falling during three hours brought down 8 times as many spores as were deposited during the same hours on a similar area exposed to wind but screened from rain.