Bacterial populations such as Xanthomonas spp. causing bacterial leaf spot in tomato and capsicum and Pseudomonas syringae pv. tomato causing bacterial speck in tomato, often develop copper tolerance. This means they can tolerate higher concentrations of copper than sensitive populations. It doesn’t mean the bacteria are resistant and that copper has no effect.
Read this article from the area-wide management team at Queensland Department of Agriculture and Fisheries to find out more about how copper protects plants from bacterial infections, the types of copper products, suggested spray program, as well as future research directions.
