– Hosts and Symptoms:
– Hosts:
– Pathogen to many forage crops
– Includes Alfalfa, Sweet clover, Burr clover, Subterranean clover, Crimson clover, Red clover
– No attempts to discover full host range beyond mentioned crops
– Symptoms:
– Causes anthracnose in plants
– Visual symptoms: Scattered straw colored plants, Yellowing of leaves, Formation of a shepherds crook, Greyish brown lesions on lower stem, Tan leaves with black fruiting bodies visible
– Environment:
– Anthracnose most severe east of Mississippi River and south of Wisconsin
– Found in California, southern Arizona, Europe, South America, and Canada
– Moderate pressure across the United States except around Rocky Mountains
– Grows best around 25°C
– Requires substantial moisture for at least twelve hours to infect plants
– Management:
– Start scouting early in summer
– Rotate crops away from forage crops for at least two years if pathogen is found
– Plant resistant varieties with at least moderate resistant rating
– Consider highly resistant varieties if pathogen has been a problem
– Delay planting until after pathogen’s prevalent period, ideally in late summer
– References:
– Mould, Michael J. R.; Boland, G. J.; Robb, Jane (1991) – Ultrastructure of the Colletotrichum trifolii-Medicago sativa pathosystem
– Monteith, John (1928) – Clover Anthracnose Caused By Colletotrichum Trifolii
– Field Crop: Crop Scouting Manual: Integrated Pest Management Program, University of Wisconsin Madison (2002)
– Undersander, D.J. (2011) – Alfalfa Management Guide, American Society of Agronomy
– Vincelli, Paul (1993) – Kentucky Plant Disease Management Guide for Forage Legumes, University of Kentucky
– Additional Information:
– Pathogen’s presence in various regions worldwide
– Optimal growth conditions and moisture requirements
– Limited management options available
– Importance of scouting and crop rotation
– Strategies for planting resistant varieties and timing planting for best results