Effect of weather parameters and fungicidal management of leaf blight of Colocasia caused by Phytophthora colocasiae Racib

The simple and partial correlation coefficients with relative humidity (RH) were found to be positively correlated with the severity of blight. The multiple correlations between disease severity and dependent variables viz., air temperature R.H. and cumulative rainfall was found to be 0.6711, showed that R.H. was directly correlated with the severity of leaf blight of colocasia. In fungicide management trials, propineb gave cent per cent germination followed by metalaxyl + mancozeb (Unilax) (99.2%) and metalaxyl + mancozeb (Ridomil MZ) (98.4%), however, minimum disease severity (1.8%) and maximum yield (24,300 kg/ha) were recorded in metalaxyl + mancozeb (Unilax) and followed by metalaxyl + mancozeb (Ridomil MZ) with 1.9% disease severity and 20,150 kg/ha corm yield.