NUTRITIONAL-REQUIREMENTS OF ANTAGONISTS TO PEACH TWIG BLIGHT, MONILINIA-LAXA, IN RELATION TO BIOCONTROL

Different carbon and nitrogen sources and accessory substances were tested to determine their effect on the growth and sporulation of the peach twig blight pathogen, Monilinia laxa, and of three of its antagonists (Penicillium frequentans, Penicillium purpurogenum and Epicoccum nigrum), since the success in twig blight biological control by treatments with the fungal antagonists depends on the type of nutrients added to the antagonist formulation. Combinations of sucrose-ammonium tartrate, glucose-(NH4)3PO4-folic acid and lactose-KNO3 were selected from these laboratory experiments because they enhanced the growth and sporulation of P. frequentans, P. purpurogenum and E. nigrum, respectively, but not M. laxa. In glasshouse experiments, twig blight was reduced following the application of mixtures of antagonists with the corresponding enhancing nutrients.