Susceptibility of low chill peach rootstocks to Phytophthora spp

Abstract

Peach seedlings (Prunus persica L. Batsch cv. Ansbacher, Boyles, Clarke's Shanghai, Neilson (Fred Hill), Okinawa, O'Meara, Richens Nos 1,2 and 3, Tomm's Early and Tomm's Shanghai), which are commonly used as rootstocks for low chill peaches in coastal New South Wales, were all susceptible to Phytophthora cinnamomi and P. cambivora and to a lesser extent P. parasitica, P. citricola, P. cryptogea, and P. megasperma, when tested by stem inoculations in the glasshouse. Myrobalan H29C plum (P. cerasifera Ehrh.) cuttings showed more resistance than peach seedlings. Variety of seedling peach was highly significant in stem inoculation experiments, but the performance of each varied between experiments. Root inoculations in aerated nutrient solution showed all rootstocks were susceptible to P. cinnamomi, but Neilson (Fred Hill) peach was more tolerant than other seedling peaches and less tolerant than Myrobalan H29C plum. No recommendation could be made on a rootstock for low chill peaches more tolerant of root and collar rots and waterlogging.