Canadian Forest Service Publications
A possible biocontrol agent for thimbleberry in British Columbia forests. 1992. Shamoun, S.F.; Callan, B.E. Phytopathology 82(10): 1080.
Issued by: Pacific Forestry Centre
Catalog ID: 3257
Diseased leaves and stems of thimbleberry (Rubus parviflorus Nutt.) were collected north of Trail, British Columbia (B.C.) for fungi potentially useful as mycoherbicides. One such, Hainesia lythri (Desm.) Höhnel fungus was isolated from blotched leaves. This is a new host record, and the first report of this fungus in B.C. The synanamorph, Pilidium concavum formed on PDA, but only the Hainesia state was present in nature. To determine pathogenicity, unwounded and wounded (pressed on sand paper or rubbed with abrasive celite), thimbleberry leaves were inoculated with conidia (1x106/mL) and enclosed for 48 hr in plastic bags in a growth chamber at 20°C/16 hr day, 15°C/night. One week later leaves were rated on a 0-4 scale for disease severity, where 0=no symptoms and 4=75-80% of leaf surface with lesions. Wounded leaves had significantly (P=0.05) more lesions than unwounded leaves. The results, suggest the potential of H. lythri, combined with a wounding agent, as a biocontrol for thimbleberry.