ABSTRACT
The survival of plant pathogen or its vector depends on the weather conditions during the intercrop period. If the greenhouse tests show that severe root rot developed in a particular soil, the field from which the soil was taken is not planted with susceptible crop. As plants mature they become more susceptible and fungicidal spray is necessary to suppress disease if the pathogen population is large. BLITECAST was developed by plant pathologists at Pennsylvania State University. BLITECAST combined two older late blight forecasting techniques. The first of these uses the accumulation of favorable days to indicate when the first spray should be applied. The second technique incorporated in BLITECAST is one based on relative humidity and temperature. R. D. Shrum has listed three major reasons for interest in forecasting those are forecasting provides a means for determining if, forecasting helps us to identify the gaps that remain in knowledge and forecasting is also important because it is intellectually stimulating.
