Construction of a Comprehensive Meteorological Risk Index for Wheat Fusarium Head Blight Prediction Based on More than a Half-Century of Monitoring Data

Fusarium head blight (FHB) represents a critical threat to wheat production globally, not only reducing yields but also contaminating crops with harmful mycotoxins. This study aimed to elucidate new spatiotemporal patterns of FHB incidence and to develop a comprehensive meteorological risk index to enhance scientific prevention and control of the disease. Through the analysis of annual and decadal variations from 1965 to 2023, the study assessed FHB trends across four agricultural regions (I, II, III, and IV) in Jiangsu Province, located in the middle and lower reaches of the Yangtze River—a hotspot for FHB in China. Key findings include the following: Since 1965, Regions I and III consistently exhibited higher FHB incidence rates compared with Regions II and IV. Post-2000, there was a notable increase in years with high incidence rates, with Region III overtaking Region I as the region with the highest incidence. Since 2010, occurrences of FHB reaching the most severe grade (Grade 5) surpassed those in previous decades across all regions. The study also revealed a stronger correlation between meteorological factors (cumulative precipitation, number of days with rainfall ≥0.1 mm, total rainy days with ≥2 and ≥3 consecutive days of rain, total rainy days with both average daily air temperature ≥15°C and daily rainfall ≥0.1 mm, days with average daily relative humidity ≥85%, cumulative sunshine hours, and cumulative cloudy days) and the FHB incidence rates during the heading–flowering–grain filling period in Regions I, II, and III, compared with the heading–flowering period alone. This indicates that optimal temperature and high humidity during the grain-filling stage significantly contribute to the final FHB incidence rates. Despite the less apparent correlation between temperature changes and disease rates, the significant warming trend observed since 2000 has likely fostered conditions conducive to the proliferation of FHB. The comprehensive meteorological risk index, constructed to incorporate key meteorological factors during the heading–flowering–filling period, showed a strong correlation with actual disease incidences. The index demonstrated fitting accuracy rates of 84.7% for Region I, 72.9% for Region II, 83.1% for Region III, and 90.9% for Region IV, underscoring its effectiveness in predicting FHB occurrences. This tool offers both convenience and practicality, providing valuable insights for strategically managing FHB risks based on local weather conditions.