P-293 - Advancement in management strategies for dragon fruit canker in South Florida

Dragon fruit canker (DFC), caused by Neoscystalidium dimidiatum, has become a prevalent and destructive disease of dragon fruit in Florida and can cause up to 60-80% yield losses to growers if not properly managed. Current DFC management heavily relies on fungicide applications, but products with only three active ingredients are registered on dragon fruit in Florida. We have conducted studies to determine the effects of pruning on DFC, evaluate dragon fruit varieties for their susceptibility to DFC, and explore synthetic fungicides and plant-based essential oils for their potential to manage DFC. Variations in susceptibility to DFC were observed in dragon fruit varieties, with ‘Natural Mystic’ being the most tolerant. Although garlic and thyme oils were effective against N. dimidiatum in in-vitro assays, they proved ineffective in preventing DFC development in detached fruit assays. Pruning diseased stems in winter led up to 61% reduction in stem canker and 51% control of fruit canker in two local orchards. Fluazinam was the most effective fungicide tested in the field, reducing DFC severity by 93% in fruits compared to the control. Tebuconazole was among the most effective chemicals tested in detached fruit assays, reducing DFC severity by 95% compared to the control, but its effectiveness decreased to 50% in field trials. Future studies will need to be conducted for better control of DFC, including exploring biocontrol products and agents for their efficacy against DFC and investigating the role of other cultural practices in sustainable dragon fruit production.