AbstractEmasculated flowers of several black currant cultivars were pollinated and then inoculated with dry conidia of B. cinerea in the field and greenhouse. The infection of the gynoecium was examined by UV fluorescence microscopy and the incidence of premature flower abscission recorded. Conidia germinated in the stigmatic fluid in all cultivars and hyphae spread symptomlessly throughout the style to infect the pericarp and ovules. Of 6 cultivars inoculated in the field, Ojebyn was the most and Ben More the least resistant to flower shedding. Natural infection of stigmas by B. cinerea was common in the field and a high proportion of apparently healthy non-inoculated flowers which abscissed were found to contain infected ovules. Fewer flowers abscissed if inoculations were made 6 d after pollination. Symptomless or latent infection of black currant flowers by B. cinerea may be a contributory cause of premature abscission of developing fruits.