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POSTERS: Chemical control

Evaluation of SAR Inducers for the Management of Bacterial Spot on Fresh-Market Tomatoes
Amanda Strayer-Scherer - North Carolina State University. Michelle Henson- North Carolina State University, Suzette Sharpe- North Carolina State University, Inga Meadows- North Carolina State University

Bacterial spot, Xanthomonas spp., is one of the most damaging diseases of tomato worldwide. Due to limited disease management options, growers rely heavily on copper-based bactericides, that are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study was undertaken to evaluate the efficacy of three systemic acquired resistance (SAR) inducers, LeapTM ES (Bacillus thuringiensis subsp. kurstaki strain ABTS-351), LifeGardTM WG (B. mycoides isolate J), and Actigard® 50WG (acibenzolar-S-methyl), alone or in combination with Harbour® (streptomycin) or Kocide® 3000 (copper hydroxide) as potential alternatives to the grower standard, copper-mancozeb, under greenhouse and/or field conditions. In two separate greenhouse studies, tomato plants treated with either Actigard® 50WG at 0.4 g/L alone, or in combination with Harbour® at 1.2 g/L or Kocide® 3000 at 2.1 g/L, significantly reduced bacterial spot disease severity when compared to the grower standard and water controls (P < 0.05). Under field conditions, LifeGardTM WG at 0.3 g/L significantly reduced bacterial spot disease severity when compared to the nontreated control without a significant impact on yield (P < 0.05). However, mixing LifeGardTM WG or LeapTM ES with Kocide® 3000 did not improve disease control under greenhouse or field conditions. This study highlights the potential of several different SAR inducing products for the management of bacterial spot of tomato.