Poster: Biology & Disease Mgmt: Chemical Control
Characterization of Diaporthe spp. Cadophora malorum and Neofusicoccum parvum causing cordon dieback in kiwi plant and their chemical control in Chile
G. DIAZ (1), M. Lolas (1), B. Latorre (2), E. Ferrada (2), J. Zoffoli (2) (1) Universidad de Talca, Chile; (2) Pontificia Universidad Catolica de Chile, Chile
Kiwifruits is the third largest exporter of fresh kiwifruit (Actinidia deliciosa) worldwide, with over 10,000 ha cultivated. Cordon dieback in kiwi plant has increased during the last decade in Chile. Recently, we have identified several species obtained from cordon dieback in kiwi plants. Therefore, the objectives of this work were i) to characterize by means of molecular and pathogenicity studies and ii) chemical control of Diaporthe ambigua, Diaporthe australafricana, Cadophora malorum and Neofusicoccum parvum. Pure cultures were characterized by phylogenetic analyses using three loci (ITS, β-tubulin and EF1-α). Pathogenicity test were conducted on kiwifruit canes and trunks. In vitro sensitivity and protection of pruning wounds with benomyl, pyraclostrobin and tebuconazole was evaluated. This study reveals that Diaporthe ambigua, Diaporthe australafricana, Cadophora malorum and Neofusicoccum parvum are the major fungal species causing cordon dieback, and that the protection of pruning wounds with chemical fungicide is a good measured to prevent infection in commercial orchards of kiwi plants in Chile.