Brown rot on stone fruit is of great economic importance especially in the warmer, more humid parts of New Zealand. Cunningham (1922d) recorded the apothecial stage of this fungus in New Zealand and discussed the importance of flower-bud infection. Brook (1954) and Frew (1963) working with peaches and apricots respectively concluded that blossom blight due to Sclerotinia fructicola was reduced by the application of dichlone and thiram during flowering and showed that a continuation of a spray programme with captan to within a few days of picking reduced fruit infection both at harvesting and in storage. Post-harvest hot-water treatments of peach fruits have been shown to control brown rot when fruits are held in store (Anon., 1965c, 1967). S. fructicola occurs on ripe and damaged fruits of quinces, apples, and pears (Cunningham, 1925a). This fungus has been introduced into New Zealand with nursery stock of the host.