Submitted to: American Phytopathological Society
Publication Type: Book / Chapter
Publication Acceptance Date: 8/19/2009
Publication Date: 1/30/2014
Citation: Mazzola, M. 2014. Apple Replant Disease. American Phytopathological Society. p. 67-70.
Technical Abstract: Technical Abstract: Apple replant disease is a significant impediment to the establishment of viable orchards on sites previously planted to the same or related crop. Symptoms of replant disease are evident during the first growing season. Vigorous young trees exhibit an initial period of vegetative growth after planting, however the successive periods of shoot elongation experienced throughout the growing season in healthy trees is arrested in infected trees. Depressed growth and yields are experienced over the life time of the orchard. The disease is primarily of a biological nature, but the reported complex of pathogens inciting the disease is extremely diverse. Many reports of causal pathogens are simply based on associative studies, thus resulting in the implication of numerous organisms that are unlikely to have a role in disease development. The majority of studies specifically focused on the etiology of apple replant disease have implicated a complex of organisms including the lesion nematode, Pratylenchus penetrans, acting in concert with a multitude of plant parasitic fungi and oomycetes including species of the genera Cylindrocarpon, Phytophthora, Pythium and Rhizoctonia. Pre-plant soil fumigation is the standard measure utilized for the control of apple replant disease in commercial orchards. Biologically-based alternatives are being developed to control the causal disease complex, however it will ultimately require the integration of multiple strategies. Host resistance is likely to be the cornerstone of such a disease management system.