Fire blight management: new products and effective rates
Author: S. Tianna DuPont
Published: 2020
Summary: Fire blight prevention trials were conducted in Washington State between 2017 and 2019 to test new products and effective rates. Trials found that the optimum range of metallic copper application for fire blight control was between 0.16 and 0.25 lbs per 100 gal per acre of metallic copper equivalent. Alum (Potassium aluminum sulfate) was most effective at 8 lbs per 100 gal. Fruit marking was low overall but with statistically significant levels for Previsto at 5 qrt/ 100gal. New product trials found that Alum at 8 to 10 lbs/ 100 gal has provided consistent positive results with an average control of 75% statistically similar to the oxytetracycline check (82% control). Copper product Instill provided 75% relative control and Mastercop (2.5 pt per 100 gal) 57% control comparable to copper standards across multiple years.
