Differential susceptibility of Malus spp. cultivars Robusta 5, Novole, and Ottawa 523 to Erwinia amylovora.
Among 25 apple cultivars inoculated with 2 E. amylovora strs. 3 were highly resistant to str. Ea 273 but were susceptible to str. Ea 266. These comprised Robusta 5 and Novole, previously identified as fire blight-resistant, and Ottawa 523. The data indicate these cultivars are differentially susceptible to str. Ea 266.