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Poster: Biology & Disease Mgmt: Chemical Control


Evaluation of conventional and biological pesticides for managing tomato bacterial spot during transplant production
P. ABRAHAMIAN (1), J. Jones (2), G. Vallad (1) (1) University of Florida, U.S.A.; (2) University of Florida, U.S.A.

Bacterial spot caused by Xanthomonas perforans, is a ubiquitous disease of tomato in both field and transplant operations in Florida. The high prevalence of copper-tolerant bacterial strains has compromised the efficacy of traditional copper compounds. Fifteen treatments consisting of various chemical and biological pesticides alone or in programs, including a non-treated control and a copper hydroxide standard, were evaluated for their ability to control bacterial spot on tomato seedlings. Treatments were foliar applied to tomato seedlings grown in 141 cell Speedling trays maintained under conditions similar to a commercial transplant operation. Each treatment was tested at least twice in four, 3-week experiments. Disease severity was evaluated on the third week. Stand-alone applications of Actigard, Cueva, Quintec, Innovotech A, and Innovotech B significantly reduced disease compared to the inoculated controls. Programs that included Actigard + Tanos + Agriphage and Tanos + K-Phite + Cueva also significantly reduced disease compared to the control. The antibiotics, oxytetracycline and streptomycin, and Agriphage were ineffective at reducing disease severity under high disease pressure. Severe phytotoxicity was associated with Quintec at rates greater than 1 fl. oz. The copper formulation in Cueva performed better than the copper hydroxide standard. Overall, Actigard provided significant disease reduction as a stand-alone or in a program with other compounds.