Pathogenicity and Formulation of Typhula phacorrhiza, a Biocontrol Agent of Gray Snow Mold

Area of Science:

• Plant Pathology
• Biological Control
• Mycology

Background:

• Gray snow mold, caused by Typhula ishikariensis and T. incarnata, is a significant turfgrass disease.
• Previous research indicated Typhula phacorrhiza as a potential biocontrol agent for gray snow mold.

Purpose of the Study:

• To evaluate the phytopathogenicity of T. phacorrhiza isolates.
• To assess the efficacy of pelletized alginate formulations of T. phacorrhiza for gray snow mold control.
• To determine the viability of T. phacorrhiza formulations under different storage conditions.

Main Methods:

• Five disease-suppressive T. phacorrhiza isolates were cultured and applied to turfgrass and winter wheat cultivars.
• Phytopathogenicity was assessed by observing winter injury post-snow melt.
• Pelletized formulations were tested for viability after storage at various temperatures.
• Field efficacy of pelletized formulations was compared to grain and wheat bran inoculums.

Main Results:

• T. phacorrhiza application did not cause significant winter injury on turfgrass or wheat, unlike pathogenic Typhula species.
• Pelletized T. phacorrhiza formulations maintained high viability (>85%) after 64 weeks of storage at -15°C.
• Low application rates of pelletized T. phacorrhiza (20 g/m²) provided gray snow mold control comparable to higher rates of grain (200 g/m²) or wheat bran (100 g/m²) inoculum.

Conclusions:

• T. phacorrhiza is a safe and effective biocontrol agent for managing gray snow mold.
• Pelletized alginate formulations offer a viable and efficient method for delivering T. phacorrhiza for disease control.
• The developed formulation enhances the practicality and effectiveness of biological control for turfgrass diseases.