JUST PUBLISHED: Strawberry host plant resistance to powdery mildew

The author (Michael Palmer) in a strawberry field in Santa Maria, CA. Photo by G. J. Holmes

Michael Palmer finished his master’s thesis last winter and his second paper just appeared in the journal Plant Health Progress (https://doi.org/10.1094/PHP-12-20-0101-RS). This paper works out the methods for screening strawberry cultivars for their susceptibility to powdery mildew caused by Podosphaera aphanis. Michael screened 10 strawberry cultivars under greenhouse conditions, then confirmed the results in the greenhouse by evaluating the same cultivars under field conditions. ‘Monterey’, which makes up 35% of the state’s acreage, is considered by growers to be highly susceptible to powdery mildew. Surprisingly it showed greater resistance than most of the other cultivars evaluated. ‘Sweet Ann’, a Lassen Canyon cultivar consistently showed the highest levels of resistance while BG 3.324 (Berry Genetics) and Royal Royce (UC Davis) were highly susceptible.

Figure. Mean disease severity for 10 strawberry cultivars evaluated under greenhouse conditions.

Out of the 10 cultivars evaluated, five of them (Monterey, San Andreas, Cabrillo, Petaluma and Sweet Ann) make up 52% of the California strawberry acreage. We continue to evaluate strawberry genotypes for resistance to this important disease and will report future results in this blog.

For the full details on this work see: Palmer, M.G. and Holmes, G.J. 2022. Characterization of strawberry host plant resistance to powdery mildew caused by Podosphaera aphanis. Plant Health Prog. 23: 82-86. https://doi.org/10.1094/PHP-12-20-0101-RS