COMPARAÇÃO DE PRODUTOS BIOLÓGICOS E QUÍMICOS NO CONTROLE DA MANCHA BACTERIANA EM TOMATE PARA PROCESSAMENTO

Abstract

Bacterial spot is one of the main diseases found in tomato crops destined for industrial processing. Epidemics of the disease in these areas are associated with the species Xanthomonas perforans. Disease control is complex, due to the absence of resistance sources and difficulty in eliminating inoculum sources, being based on the application of copper fungicides. Some products have shown good efficiency in controlling the disease, such as strobirulin. Products of biological origin, such as microbial formulations and plant extracts, have also been constantly evaluated. In this sense, the present work evaluated the efficiency of the combination of some of these products in the control of bacterial spot in tomatoes for processing. Seedlings cv. Heinz 9553 (25 days after sowing) were transplanted, following the spacing of 1m between rows and 0.33m between plants. The experimental plot consisted of three rows of 5 m. Treatments were evaluated with the application of formulations based on metiram + pyraclostrobin (MP), fluxapyroxad + pyraclostrobin (FP) azoxystrobin + mancozeb (AM), kasugamycin (C), acibenzolar-S-methyl (ASM), copper hydroxide (HC), based on Bacillus amyloliquefaciens (Ba) and based on Melaleuca alternifolia essential oil. The applications started 7 days after planting (DAT), being carried out weekly, over 10 weeks with the rotation of the products. Inoculation occurred at 30 DAT, by spraying bacterial suspension (X. peforans, ~5x107 ufc/mL). Severity assessments were carried out throughout the cycle, with the harvest being carried out at 120 DAT. The experiment was conducted in a randomized block design, with 4 replications for each treatment. All treatments were compared with the untreated control. All treatments reduced disease severity, with emphasis on MP, FP, and Ba treatments. The 2 treatments provided productivity increments above 10 t/ha in relation to the control, not differing from each other. The use of products of biological origin had a similar performance to cupric FP and can be used as another tool in the control of bacterial spot on tomato in ground cultivation of tomatoes for processing.