Field and greenhouse inoculation trials are described and the results obtained are presented. Only minor differences were detected in host susceptibility in both the glasshouse and field and ranking of genotypes varied depending on whether or not flowers had been inoculated. The susceptibility of pistils of 40 Rubus genotypes to infection was examined 7 and 28 days after inoculation of stigmas with dry conidia. Conidia germinated on the stigmas and produced hyphae which grew through transmitting tissues of the styles to infect carpels symptomlessly in 17 red raspberries, one blackberry, 2 Rubus spp. and one hybrid. No germination occurred on stigmas of raspberry cv. Carnival and New York Selection 817.