Further suppression of Botrytis cinerea disease in cucumber seedlings by chitosan-copper complex as compared with chitosan alone

Chitosan-copper complex compared with chitosan alone enhanced suppression of Botrytis cinerea rot development on four-true-leaf cucumber seedlings in controlled growth chambers. This paper constitutes the first report of such enhancement. The optimal concentrations for the most effective suppression of Botrytis development were 0.2 g l(-1) chitosan and 1.6 mmole copper. After 12 days' incubation, marked and significantly better disease suppression was obtained with chitosan-copper complex (75% suppression) than with chitosan alone. The chitosan-copper complex could be a very promising decay control agent for use in both conventional and organic agriculture.