EFFICACY OF A NEW DISINFECTANT IN CONTROLLING BACTERIAL SPOT AND PITH NECROSIS CAUSED BY Xanthomonas perforans ON TOMATO

Since the phase-out of methyl bromide (MB), the disinfection of soil is the most important task in vegetable crops to reduce the diseases caused by both bacterial and fungal pathogens. Xanthomonas perforans is a bacterial pathogen, known as causal agent of leaf spot and pith necrosis on tomato and pepper. During 2013, two trials were carried out to evaluate the efficacy of a new disinfectant JetFive®, containing 5% peracetic acid and 20% hydrogen peroxide, for controlling both leaf spot and pith necrosis symptoms caused by X. perforans strain 4P1S2 on tomato cultivar Sir Elyan. JetFive® was applied at two different rates, 2 and 4 mL/L, both before and after inoculation of pathogen. The effect of this compound in reducing disease incidence and severity was compared with the activity of Cu-hydroxide (Funguran-OH® 250 SC, Certis Europe), applied at rate of 2.8 mL/L, and the biological control agent B. subtilis (Serenade® Max, BASF), applied at rate of 4 g/L. This research showed that the treatments were variably effective in reducing tomato leaf spot and pith necrosis. Significant reductions of bacterial disease symptoms were always found in plants treated with JetFive® at 4 mL/L and Cu-hydroxide. JetFive® also showed a significant reduction of disease incidence and severity when it was used as curative treatment after pathogen inoculation. On the other hand B. subtilis was the least effective in reducing bacterial leaf spot and pith necrosis. The treatments were selective versus tomato plants without any phytotoxicity effects.