Abstract

Conidia of 2 isolates of E. veneta were consistently produced in vitro by a 3-stage culture system in which sparsely sporulating microcolonies produced on corn meal agar were used to seed Czapek-Dox V8 juice agar. E. veneta then sporulated on this medium if discs were floated mycelium uppermost on sterile distilled water for 24 h at 25C. Both isolates also produced microconidia in vitro. Only the growing apices of raspberry canes were susceptible to infection. Of 12 genotypes inoculated in the greenhouse, a red raspberry derivative of Rubus coreanus, EMRS 2769/9, was the most resistant and the black raspberry selection SCRI 8152B6 and Malling Delight raspberries were the most susceptible. Of 4 red raspberry cultivars inoculated in the field, Malling Orion was the most susceptible. Inoculated flowers and developing fruits produced malformed fruits because infected drupelets were smaller or slower to ripen than uninfected ones.