SUSCEPTIBILITY OF RED, BLACK AND PURPLE RASPBERRY CULTIVARS TO THREE PHYTOPHTHORA SPECIES UNDER GREENHOUSE AND FIELD CONDITIONS

Raspberry cultivars were evaluated for their susceptibilities to Phytophthora fragariae var. rubi under greenhouse and field conditions and to P. citricola and P. megasperma in the greenhouse only.
Results from the field and greenhouse evaluations were qualitatively similar for most cultivars but disease was more severe in the greenhouse trials, making it difficult to distinguish moderately resistant cultivars. ‘Latham’ and the related cultivars, ‘Boyne’, ‘Killarney’ and ‘Nordic’, showed excellent resistance to P. fragariae var. rubi under field conditions, confirming that this trait is highly heritable. ‘Latham’ also showed good resistance to the same pathogen in the greenhouse trials, but appeared much more susceptible to P. citricola and P. megasperma under these conditions, which involved periodic episodes of soil flooding.
In the greenhouse trials, two black raspberry (Rubus occidentalis) cultivars, ‘Jewel’ and ‘Bristol’, showed levels of resistance to P. fragariae var. rubi that were equivalent to that of ‘Latham’, suggesting that this plant species might represent a previously-unrecognized source of resistance to the pathogen.

VII International Symposium on Rubus and Ribes

W.F. Wilcox, J.R. Nevill, J.A. Burr

Root rot, Phytophthora citricola, Phytophthora fragariae var. rubi, Phytophthora megasperma, Rubus idaeus, Rubus occidentalis

https://doi.org/10.17660/ActaHortic.1999.505.31