Inhibition of germination and growth of Alternaria alternata and mouldy-core development in Red Delicious apple fruit by Bromuconazole and Sygnum.

摘要

Alternaria alternata is the predominant fungal pathogen responsible for mouldy-core in Red Delicious strains of apple. This study reports on the effects of sygnum (a premix fungicide containing pyraclostrobin+nicobifen), and the sterol biosynthesis inhibitor bromuconazole on spore germination, mycelial growth, decay on detached fruits, and control of mouldy-core caused by A. alternata. Germination was more sensitive to sygnum than to bromuconazole. The 50% and 90% effective concentrations (EC50, and EC90) for in vitro inhibition of conidial germination of the fungus of sygnum were 20 and 79 micro g ml-1, respectively, whereas those of bromuconazole were 57 and 735 micro g ml-1, respectively. Mycelial growth in vitro of A. alternata was more sensitive to sygnum (EC50 and EC90 values of 2 and 4 micro g ml-1, respectively) than to bromuconazole (EC50 and EC90 values of 47 and 95 micro g ml-1, respectively). Decay formation by A. alternata on mature detached fruits was also more affected by sygnu