Splash dispersal of <i>Botryosphaeriaceae</i> species in Marlborough vineyards

Abstract

Botryosphaeriaceae species cause dieback and canker in many woody hosts including grapevines with infection occurring when conidia are released during rainfall and splash borne to pruning and trimming wounds This study monitored dispersal of naturally released conidia of Botryosphaeriaceae species in three Marlborough vineyards with a Burkard spore trap and rain water traps Microscopic examination of the Burkard tape and trapped rain water confirmed the presence of Neofusicoccum and Diplodia spp Species were identified on tape and in rainwater with single stranded conformational polymorphism as N luteum N parvum/Nribis N australe D mutila and D seriata To determine conidium dispersal distances sporulating shoot lesions of N parvum isolate B2141 for which an isolate specific marker was developed were placed in one Marlborough vineyard before forecast rainfall periods The rainwater traps were set up around the sporulating lesions at 05 to 20 m in the direction of the prevailing wind and 05 to 5 m in three other directions After 2 days rain Neofusicoccum sp conidia were identified in the collected rainwater by microscope and with the isolate specific PCRRFLP (restriction fragment length polymorphism) for N parvum B2141 This isolate dispersed up to 10 m in the wind direction and up to 1 m in the other three directions