Abstract:

In order to improve the monitoring ability of wheat meteorological diseases, based on the historical meteorological data and observation data of wheat scab in Jiangsu province, from the aspect of the scab infection process, the appropriate meteorological conditions were analyzed for the development of scab, the disease promotion indices of wheat key growth stages were given. A comprehensive humidity and heat index model was then constructed to classify the meteorological suitable level of the occurrence of wheat scab. In addition, meteorological suitable level prediction techniques were studied and their accuracy was tested. The results showed that the disease promoting indicators for wheat growth stages include booting to heading, heading to flowering and flowering to milk ripening were T≥14℃ and RH≥70%, T≥16℃ and RH≥68%, T≥18℃ and RH≥70%, respectively. Site−scale tests found that the model’s accuracy was more than 70% in the simulating levels of Fusarium head blight, and that it was in high agreement with observations of moderate to severe outbreaks of Fusarium head blight in 2002, 2003 and 2012. At the same time, the regional scale test showed that model could also accurately predict the epidemic areas and occurrence levels of diseases in typical years well, indicating it was more prevalent along the Huai river and the southern part of the Yangtze river in Jiangsu province, and spatially presented a "heavy in the south and light in the north" characteristic. Combined with refined weather forecasting products, this model had a good ability to predict and identify the spatiotemporal changes in the occurrence and development of typical Fusarium head blight epidemics. As the comprehensive humidity and heat index model well reflects the typical occurrence year and the variations in region and degree of the disease, it could be used to determine the meteorological suitability level for wheat Fusarium head blight in Jiangsu province, thereby potentially reducing the risk of disease occurrence more effectively.

Key words: Wheat scab, Comprehensive humidity?heat index, Meteorological suitable grade, Prediction