Preliminary antagonistic tests of endophytic fungi against Diplodia corticola and silvicultural practices to contrast oak decline

In southern Italy, many oak stands have been affected by the decline syndrome attributed to several biotic and abiotic causes. Various fungal microorganisms, such as Diplodia corticola A.J.L. Phillips, Alves & Luque, were found to be associated with the syndrome, demonstrating either an endophytic asymptomatic or a pathogenetic behaviour, or both, in succession. The objective of this study was to examine a first series of in vitro tests conducted on the antagonistic activity of some endophytic fungi belonging to the species Trichoderma viride Pers.: Fries, Epicoccum nigrum Link., Fusarium tricinctum (Corda) Sacc., Alternaria alternata (Fries) Keissler, Sclerotina sclerotiorum (Libert) De Bary and Cytospora sp. towards D. corticola. These endophytic fungi were obtained from four declining oak woods in Southern Italy. A secondary aim was to define a correct silvicultural interventions to contain decline in the oak stands from which the fungi were extracted.