Environmental and Edaphic Factors that Influence Spring Dead Spot Epidemics

Area of Science:

• Plant Pathology
• Soil Science
• Turfgrass Management

Background:

• Spring dead spot (SDS), caused by *Ophiosphaerella* spp., affects warm-season turfgrasses during winter dormancy.
• The specific soil (edaphic) factors driving SDS epidemics are not well understood.

Purpose of the Study:

• To investigate the relationship between edaphic factors and SDS development in 'TifSport' hybrid bermudagrass.
• To identify key soil conditions influencing SDS intensity on golf course fairways.

Main Methods:

• Aerial imagery from drones was used to map SDS intensity zones (low, moderate, high).
• Soil samples, firmness, thatch depth, and organic matter were measured in 120 plots across four fairways.
• Multivariate correlation and stepwise regression analyses identified influencing edaphic factors.

Main Results:

• Edaphic factors associated with increased SDS varied significantly between fairways and years.
• Soil pH and thatch depth were identified as potential predictors for SDS in some instances.
• No single edaphic factor consistently correlated with SDS occurrence across all conditions.

Conclusions:

• This foundational study highlights the complex and variable nature of edaphic factors in SDS development.
• Results provide a basis for future research to better predict and manage SDS epidemics.
• Understanding these relationships can guide targeted management strategies for turfgrass health.