Kerala Agricultural University, Regional Agrl. Research Station, Kumarakom, Kottayam, Kerala.
Sheath blight caused by Corticium sasakii and sheath rot caused by Sarociadium oryzae are serious diseases of rice crop in Kuttanad, Kerala. Studies on disease-weather correlations for these diseases indicated significant relationships with minimum temperature. The incidence of sheath blight and sheath rot was higher for the April - May and November - December sowings when the minimum temperature range was between 23–26 OC with relative humidity around 70%. The correlation of disease incidence with relative humidity, number of rainy days, and maximum temperature was not significant. Tests of multiple correlation coefficients and partial regression coefficients revealed that sheath blight and sheath rot diseases are not exclusively go-verned by any of the weather parameters.
