Comparative Response of Red Raspberry Cultivars to Phytophthora Root Rot

Thirty red raspberry genotypes, including newly released cultivars and advanced selections from diverse breeding programs, were evaluated for response to Phytophthora root rot over three years on a natively infested field site. Plants were evaluated quantitatively and qualitatively for root rot symptoms and cane growth over three years and compared to known resistant and susceptible cultivars. Cultivars 'Cascade Bounty', 'Jaclyn', 'Newburgh', 'Cascade Delight', 'Prelude', 'Sumner', Moutere', Ukee', 'Josephine', and advanced selections WSU 1499 and WSU 1447 had root rot responses similar to 'Summit' and were identified as resistant to the disease.