Environmental Factors Influencing Stem Rot Development in Peanut: Predictors and Action Thresholds for Disease...

Area of Science:

• Plant Pathology
• Agricultural Meteorology
• Crop Science

Background:

• Peanut stem rot, caused by Athelia rolfsii, is a significant soilborne disease affecting crops globally.
• Current stem rot management relies on predetermined fungicide application intervals due to a lack of environmental-based predictive models.
• This necessitates the development of more precise disease management strategies.

Purpose of the Study:

• To investigate the relationship between environmental factors and the development of peanut stem rot.
• To identify key environmental variables that predict the germination of Athelia rolfsii sclerotia and subsequent disease progression.
• To develop an environmental-based model for optimizing stem rot control in peanut crops.

Main Methods:

• Inoculated field experiments were conducted over six site-years in North Florida.
• Environmental data including soil temperature, soil moisture, relative humidity, and precipitation were collected.
• Window-pane analysis, correlation analysis, regularized regression, and decision tree analysis were used to model disease development.

Main Results:

• Within-canopy soil temperature and relative humidity were identified as the most influential environmental variables.
• A decision tree model using hours of canopy relative humidity above 90% and soil temperature between 25-35°C within a 14-day window accurately predicted disease scenarios.
• The two-variable model showed improved predictive power (adjusted R² = 0.61).

Conclusions:

• Environmental factors, specifically canopy relative humidity and soil temperature, are critical predictors of peanut stem rot progression.
• An easy-to-interpret decision tree model provides an actionable threshold for disease management.
• Integrating these environmental predictors with preseason risk indices can optimize stem rot management strategies.