Occurrence of corn rust disease and meteorological factors.
The most important factors influencing maize rust development in Taiwan, (caused by Puccinia polysora and P. sorghi) were identified as temp. 7 d before disease occurrence in the spring crop and temp. 8-14 d before disease occurrence on the autumn crop. A series of equations was derived from the relationship between increasing percentage of infected leaf area and meteorological factors, and another from the relationship between infection rate and meteorology. The predicted disease values obtained from these equations corresponded closely to the observed values, and it is suggested that the equations could be used to predict outbreaks of maize rust.