Bivariate analysis reveals the spatial-temporal trends of maize yield losses from diseases across China's agroecological regions over two decades

Maize yield is critically endangered by diseases throughout its growth cycle, posing significant risks to food security. The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to these threats on a regional scale have been challenging to ascertain due to scarce continuous observation data. This study compiled county-level data on maize yield and yield loss across China's six primary cropping regions over twenty years from 1999 to 2018. These include the Spring-sown area of Northern China (1-NC), the Summer-sown Huang-Huai-Hai Plain (2-HHP), the Southwest Mountain (3-SM), the Southern Hilly (4-SH), the Northwest Irrigated (5-NI), and the Qinghai-Tibet Plateau Maize Regions (6-QTP). We identified 15 major diseases affecting these regions. The annual average yield loss due to maize diseases in the regions 1-NC, 2-HHP, 3-SM, 4-SH, 5-NI, and 6-QTP were 0.40, 0.58, 0.12, 0.05, 0.04 and