Cause 'Blackberry Collapse' has appeared in commercial 'Columbia Star' and 'Black Diamond' fields in the Willamette Valley of Oregon. Other names for this disease may include "Cane wilt and canker". The fungi Gnomoniopsis idaeicola, Kalmusia coniothyrium (the cane blight pathogen) and Botrytis sp. have been associated with these collapsed plants and can cause cane lesions. Necrosis was largest on canes inoculated with G. idaeicola. This same pathogen has been found on wild Rubus spp. in the Pacific Northwest. Losses in Serbia have been high on the cultivar Loch Ness and on cultivars grown in Iran.
Symptoms The main symptom is a sudden wilting and death of entire plants in semi-circular patches in the field. In these areas there is general weakness of plants having fewer and shorter primocanes, floricane reddening, and premature floricane senescence. There may be irregular lesions on the canes which may be brown or purplish. Also, there may be necrosis at the clasping end of a petiole and death of nearby buds. Sunburn may also be observed on affected plants.
Control None have been developed short of managing the known pathogens involved.
Reference Stockwell, V.O., Shaffer, B.T., McGhee, G.C. and Hardigan, M.A. 2022. First Report of Gnomoniopsis idaeicola Causing Cane Wilt and Canker in Commercial Blackberry Fields in Oregon. Plant Disease. 106:1980-1981.