Dynamic trends in maize diseases and pests across six regions in China over two decades

Maize production faces persistent threats from maize diseases and pests (MDPs) throughout its growth cycle, posing substantial risks to food security. However, understanding the spatio-temporal dynamics of MDPs occurrences on a regional scale has remained elusive due to a lack of continuous observation data. This study curated a comprehensive dataset spanning two decades, from 1999 to 2018, across six key maize planting regions in China [Spring sown area in Northern China (1-NC), Summer sown region in Huang-Huai-Hai Plain (2-HHP), Southwest Mountain Maize Region (3-SM), Southern Hilly Maize Region (4-SH), Northwest Irrigated Maize Region (5-NI), and Maize Region in Qinghai-Tibet Plateau (6-QTP)]. The average extent of MDP occurrence in 1NC and 2-HHP exceeded that in other regions over the two-decade period. Furthermore, the occurrence of MDPs exhibited a substantial increase in 1-NC, 2-HHP, 3-SM, 4-SH, and 5-NI over the same period. Meanwhile, the average occurrence intensity of MDPs in 2-HHP surpassed that in other regions. Notably, maize leaf blight and the Asian maize borer emerged as predominant diseases and pests in 1-NC, 2-HHP, 3-SM, 4-SH, and 5-NI. A bivariate trend analyses highlighted a notable increase in the species count for both the extent and intensity of MDP occurrences, including double-spotted leaf beetle in 1-NC, and cotton bollworm in 2-HHP. This extensive, long-term analysis offers a foundation for devising comprehensive strategies for MDP control on a national scale, enabling the formulation of tailored forecasting and control measures across six planting regions.