Evaluating the Efficacy of Commercial Products for Management of Bacterial Leaf Spot on Lettuce

Abstract

The efficacy of Serenade, Maneb, Cuprofix, and mixtures of these products were evaluated for efficacy in reducing disease incidence and severity of bacterial leaf spot of lettuce caused by Xanthomonas campestris pv. vitians in six trials at two locations between 2001 and 2003. Additionally, Messenger, elemental copper, Quadris, and Actigard were evaluated in at least two of these trials. Mixtures of Serenade and Cuprofix reduced disease incidence in three of six experiments and reduced disease severity in a fourth experiment. Treatment with the Maneb and Cuprofix mixture was less effective but resulted in significantly less disease and lower severity in single experiments. These results indicate that a mixture of Serenade and Cuprofix may be a useful addition to an integrated bacterial leaf spot disease management strategy but this treatment may be too variable to justify it as a stand-alone treatment. Accepted for publication 21 October 2005. Published 21 November 2005.