Risk factor analysis for outbreak of leaf rust on wheat in Aichi Prefecture

To elucidate the cause of a severe outbreak of wheat red rust in Aichi Prefecture, a statistical analysis was performed on survey data from 2015 to 2019. The survey was conducted in local cultivation fields in Aichi Prefecture. The results showed that initial disease development in late April was related to the occurrence of severe epidemics in late May. Furthermore, using logistic regression analysis with the disease state in late April as the objective variable, we revealed that the number of days with an average temperature above 12 °C and rain from February 1 to March 31 were significantly related. Additionally, exposure to these conditions for more than 4 days was likely to increase the risk of severe disease occurrence. This discovery makes it possible to predict whether severe disease will occur during the appropriate control period. Thus, our findings could help ensure that this disease is effectively suppressed.