Integrated control ofChondrostereum purpureumin plum by treatment of pruning wounds

Abstract

SummaryThree fungicides effective against basidiomycetes were tested against spore germination and mycelial growth of Chondrostereum purpureum (silver leaf disease) in vitro. The most active was furmecyclox, triadimefon and benodanil having smaller effects. Experiments were done to determine the effectiveness of these materials in vivo and to establish their usefulness in an integrated programme with Trichoderma viride, a potential antagonist of C. purpureum. When applied in droplets to pruning wounds on plum trees triadimefon and benodanil gave good protection against C. purpureum whereas furmecyclox was poor. Excellent protection of pruning cuts following artificial inoculation with C. purpureum was achieved in two field experiments by applying Trichoderma viride or T. viride in combination with triadimefon. Colonization of shoots by T. viride was not adversely affected by the addition of triadimefon to the spore suspension, whereas benodanil was inhibitory. In one of the field experiments treatments were applied with modified pruning secateurs. These were an efficient method of transferring T. viride propagules to the cut surface of plum shoots during pruning.