Blossom wilt is an occasional disease of dessert and culinary apples but where it occurs on very susceptible varieties such as James Grieve, Cox and Lord Derby it can cause significant losses . The disease is much more prevalent on cider apples where most …
Despite remarkable challenges, the 2021/22 season was agronomically average; whilst variable between locations, disease levels in most crops were average or below and harvest yields, although variable with soil type and crop, were average to good.Yes, a …
Phytophthora spp attack the roots and trunks of apple trees and are responsible for crown, collar and root rots of apple trees. Phytophthora cactorum is the main species responsible for crown and collar rot. Occasionally P. syringae may also cause bark …
P. cactorum and P. syringae cause diseases of a wide range of other economic plants, woody and herbaceous, including strawberry and pear. There is evidence for host adapted strains of P. cactorum . Most significant is that strawberry crown rot is caused …
P. cactorum is widespread in apple growing regions of the world. P. syringae is a significant pathogen of apple only in northwestern Europe. P. cactorum and P. syringae occur widely in English apple …
Rootstocks Rootstocks vary in their susceptibility to P. cactorum . M.9 appears most resistant, but reports suggest regional differences in rootstock susceptibility. M.2, M.7, M.26 and MM.111, which are very resistant under UK conditions are susceptible …
Rootstock Origin Effect Phytophthora susceptibility Fireblight Woolly aphid Other M.27 HRI-East Malling super dwarf ? ? susceptible susceptible to winter cold and drought G 65 Cornell, USA super dwarf resistant resistant ? experimentalsimilar to M.27 JM1, …
Usually P. cactorum and occasionally P. syringae are the fungi responsible for crown rot and collar rot in the UK and Europe, but more recently, particularly in other parts of the world, other species of Phytophthora have also been implicated. P. cactorum …
Foliar symptoms Foliar symptoms are likely to be the first indication of crown or collar rot, but are not diagnostic, merely indicators of root or vascular problems in the tree. Affected trees are unthrifty, showing poor extension growth. Foliage is often …
Crown rot Check young orchards on susceptible rootstocks in spring and late summer/autumn looking for trees that fail to leaf out or that do develop autumn colours earlier than normal. Examine the rootstock below ground of such trees for signs of bark …
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