In this installment of the UF/IFAS TREC’s Research Report, you’ll learn about Dr. Shouan Zhang and the research being conducted in his vegetable pathology lab. Dr. Shouan Zhang’s research program focuses on the detection and identification of invasive diseases threatening vegetable production in south Florida. Another aspect of the research conducted in his lab is the biology, epidemiology, and management of economically important diseases on traditional and alternative vegetable crops and dragon fruit. At this time, researchers in Dr. Zhang’s lab are exploring the interaction between soil salinity and tomato bacterial spot disease and practical practices to manage Dragon Fruit Canker (DFC).
Vegetable pathologies on tomato
Tomato is one of most important vegetable crops grown commercially in south Florida with Florida’s fresh market value totaling $336.5 million. Unfortunately, due to south Florida’s nutrient-deficient soil, overfertilization of crops could be a problem. W
hen combined with poor irrigation management, some farm lands in south Florida have been found to have saline issues. How these saline issues affect tomato growth is one focus of the dissertation research being conducted by Ketsira Pierre, a PhD student in Dr. Zhang’s lab. Ketsira’s research is also looking into how soil salinity affects bacterial spot, an economically important disease caused by a bacterium Xanthomonas euvesicatoria pv. perforans (X. perforans for short) on tomato. To learn more about how this pathology affects vegetables, like tomatoes, in south Florida, check out the Student Spotlight on YouTube!
Assessing DFC, a disease of dragonfruit
Due to the citrus and avocado industries being severely impacted by huanglongbing and laurel wilt, respectively, growers in south Florida have been on the lookout for alternative crops. One low-maintenance alternative crop which has been planted in this region is dragon fruit, a climbing cactus with a short time period from planting to first harvest (Hong, et al, 2023). Unfortunately, growers in south Florida have been experiencing significant losses due to DFC, a prevalent disease caused by the fungal pathogen Neoscytalidium dimidiatum (N. dimidiatum). Although N. dimidiatum has been reported in southeast Asia including India, the Middle East, and the Americas (Ecuador, Puerto Rico), due to the absence of a dis
ease assessment standard, there was no way for researchers across these continents to accurately compare the severity of the disease. Drs. Zhang and Pamela Dutra, a postdoctoral scientist in Dr. Zhang’s lab, have collaborated with colleagues from Brazil to develop a standard area diagram (SADs) for the accurate assessment of DFC. You can learn more about the SADs for DFC severity in their latest publication. To learn more about Dr. Dutra, we encourage you to review the “Post Doc Exposé” from the Spring issue of Inside TREC.
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