Agriculture, Aquaculture and Fisheries - Effect of Saponins of Chenopodium quinoa Applied as Seed or Foliar Treatments on Dry Rot, Common Scab and Black Scurf Diseases of Potato

Partner: Potatoes New Brunswick

Abstract: Dry rot, black scurf and common scab are three potato diseases of economic importance throughout the world. Field trials conducted in 2005 and 2006 in New Brunswick assessed the efficacy of saponins extracted from Chenopodium quinoa (SCQ; HeadsUp®) used as foliar or seed treatments. Trials consisted of: 1) untreated, inoculated or infected control; 2) seed inoculated or infected and treated with SCQ; 3) seed inoculated or infected and the foliage treated with SCQ; and 4) seed inoculated or infected and treated with Maxim® PSP. After harvest, tubers were assessed for the severity of dry rot, black scurf and common scab. Tubers were sized and weighed and assessed for disease severities. All treatments significantly reduced the severity of dry rot by 32.4-46.7%; common scab by approximately 30%; and black scurf by 61.2-76.5% relative to the untreated, inoculated/infected controls. Seed and foliar treatments with SCQ increased the total yield compared to the untreated, inoculated/ infected control. Seed treatment with SCQ increased marketable yield by 23.8-26.2% while foliar treatment increased marketable yield by 16.8-23.8%. Results indicate that saponins from C. quinoa can be used as a potentially viable option for managing dry rot, black scurf and common scab diseases of potato.