Metalaxyl sensitivity of Phytophthora spp. obtained from red raspberry fields in British Columbia
Sapkota S and Burlakoti, RR.2021. Metalaxyl sensitivity of Phytophthora spp. obtained from red raspberry fields in British Columbia. The Professional Pest Management Association of British Columbia 2021 Symposium, February 18-19, Virtual.
Phytophthora root rot (PRR), caused by Phytophthora spp., is the most devastating disease of red raspberry in British Columbia. Multiple species of Phytophthora were detected from the infected raspberry samples based on pathogen morphology and molecular techniques Application of metalaxyl and other fungicides is commonly used to reduce the disease. To understand the sensitivity metalaxyl of strains of Phytophthora spp., 11 strains of P. rubi and 6 strains of P. gonapodyides isolated from diverse raspberry farms of BC were evaluated in vitro using radial growth method.. Fifty percent effective concentration (EC50) values, and dose response curve were determined for each strain. Preliminary results showed that 83% P. rubi and all tested P. gonapodyides strains were highly sensitive to metalaxyl with mean EC50 values 0.058 µg/ml (range 0.038 to 0.074 µg/ml) for P. rubi and 0.054 µg/ml (range 0.024 to 0.076 µg/ml) for P. gonapodyides.