Control of contamination of potatoes with air‐borne Erwinia carotovora by foliar application of copper oxychloride

摘要: SUMMARY In field experiments in 1983 and 1984, micropropagated plants of cv. Desiree planted soil tested found free erwinias became contaminated with airborne erwinias, mostly E. carotovora pv. carotovora, September when rain was more abundant, but not earlier. Control contamination progeny tubers harvested October achieved by spraying copper oxychloride (‘Cuprokylt’; 5 g litre-1) twice weekly from June or July August nor fortnightly treatments June. Bactericidal activity the effective spray regimes expressed on leaves similar sprayed unsprayed treatments. In contrast, multiplication senescent surface (leaf debris) inhibited treatment population numbers c. 103 cells g-1 fresh weight were detected. It is suggested that fewer would be washed leaf debris than to contaminate tubers.