Temporal Progress and Spatial Patterns of Northern Corn Leaf Blight in Corn Fields in China

Area of Science:

• Plant Pathology
• Agricultural Science
• Epidemiology

Background:

• Northern corn leaf blight (NCLB), caused by *Exserohilum turcicum*, is a significant corn disease in China.
• Understanding NCLB epidemiology is crucial for effective disease management strategies.

Purpose of the Study:

• To investigate the temporal progress and spatial patterns of NCLB in Beijing.
• To identify key factors influencing NCLB epidemics.

Main Methods:

• Monitoring NCLB incidence and lesion counts in susceptible corn cultivars over two growing seasons.
• Analyzing temporal disease progress using logistic models.
• Assessing spatial patterns of disease distribution using statistical methods (join-counts, variance of moving window averages, semivariogram analysis).

Main Results:

• A logistic model accurately described NCLB temporal progress.
• Initial disease incidence was the primary factor determining final NCLB severity.
• NCLB leaf lesions and infected plants exhibited aggregated spatial patterns within fields.
• Local spread via conidia appears significant in disease dissemination.

Conclusions:

• Early detection and monitoring of NCLB incidence are critical for predicting disease severity.
• The aggregated spatial distribution of NCLB necessitates comprehensive field sampling for accurate incidence estimation.
• Understanding disease spread patterns can inform targeted control measures for NCLB in corn.