The Effect of Temperature and Relative Humidity on the Longevity of the Conidia of Helminthosporium Oryzae

SUMMARY

1.	Low temperatures favored the retention of viability by the conidia of Helminthosporium oryzae.
2.	In controlled temperature experiments in which the relative humidities during storage were controlled with sulfuric acid solutions, the conidia remained viable longer under cool dry conditions. At 20% relative humidity the conidia survived for six months with little loss of viability even when stored at 31° C., whereas at 95% relative humidity they failed to germinate after one month at 31° C.