Extratos vegetais, formulações a base de extrato vegetal e produtos químicos no controle da mancha bacteriana do maracujazeiro

Abstract

The bacterial spot is an important disease in passion fruit culture responsible for economic damages and for reducing fructification and commercial exploitation period of affected plants. The present research aimed to evaluate the effect of the chemicals oxytetracycline, fluazinam, mancozeb, copper oxychloride and acibenzolar-S-methyl (ASM) and the formulations Fitoforce Copper and Fitoforce Plus and leaf extracts of Artocarpus heterophyllus and Morinda citrifolia on growth in vitro of Xanthomonas axonopodis pv. passiflorae and the severity of bacterial spot of passion fruit in greenhouse. For the in vitro tests, treatments were incorporated into the culture medium 523 on their respective strengths and assessments were performed by counting the number of colonies of the pathogen. The tests on greenhouse treatment application were performed 7 days before inoculation of X. axonopodis pv. passiflorae for formulations and extracts and 2 days before inoculation for chemicals. The disease severity assessments were performed every 48 hours. Oxytetracycline, fluazinam mancozeb, copper oxychloride, Fitoforce Copper and Fitoforce Plus completely inhibited bacterial growth in vitro. At the greenhouse all treatments reduced the severity of bacterial spot of passion fruit with reductions between 54 e 62%, except for fertilizer Fitoforce Plus that showed a lower percent control, below 50%.