Growth of Agrostis palustris in Response to Adventitious Root Infection by Curvularia lunata

Curvularia lunata is reported as a minor pathogen of adventitious roots of Agrostis palustris. C. lunata isolates from roots of A. palustris were evaluated for their ability to infect adventitious roots at temperatures ranging from 23 to 48°C. All isolates of C. lunata decreased both the shoot and root growth of root-inoculated plants during a 10-week observation period, but failed to produce the foliar symptoms observed in the field. Shoot and root weights of inoculated, plants were 47–66% and 55–69% of their respective controls. Infected roots were light tan in colour without lesions or rot, and infections were restricted to root hairs and cortical tissue. These observations are discussed relative to the nature of the pathogenicity of C. hunata as a root pathogen and its potential function in a root disease complex.