Association of the Pitch Canker Fungus with Cones and Seeds of Pines

Abstract

The pitch canker fungus, Fusarium subglutinans f. sp.pini, causes the mortality of female flowers and mature cones, and can infect and destroy gametophyte tissues of seeds of several pine species in the southeastern U.S. The fungus can also be associated with the seed coats of apparently healthy, viable pine seeds. The pitch canker fungus was isolated from wash water from Monterey pine cones at all sampling locations in central coastal California, and the frequency of isolations was greatest in those areas, except Sunset Beach State Park, where the disease was the most common, and least where evidence of disease is low or absent. Assaying Monterey pine cones for surface contamination by F. subglutinans f. sp. pini may be useful in monitoring the inoculum level in geographical locations. The incidence of contamination of Monterey pine seeds also varied significantly by location. The contamination of longleaf, shortleaf, and Monterey pine seeds by the pitch canker fungus appears to be primarily external, although the presence of some internal contamination in some seed lots cannot be dismissed. External contamination of pine seeds can be reduced or eliminated by appropriate seed treatments.

Citation

Dwinell, L. David. 1998. Association of the Pitch Canker Fungus with Cones and Seeds of Pines. Current and Potential Impacts of Pitch Canker in Radiata Pine: Proceedings of the IMPACT Monterey Workshop, Monterey, California