Controle preventivo da mancha alvo do pepineiro com produtos à base de Bacillus spp.

• DOI: https://doi.org/10.22533/at.ed.09736226010411

• Palavras-chave: Cucumis sativus, Corynespora cassiicola, controle biológico

• Keywords: Cucumis sativus, Corynespora cassiicola, biological control

• Abstract: Target spot, caused by Corynespora cassiicola, occurs in several cultivated species and is considered an important disease of cucumber. This study aimed to evaluate the efficacy of commercial microbiological fungicides based on Bacillus spp. for in vitro control of the pathogen and for preventive disease control under greenhouse conditions. Inhibition of mycelial growth was assessed on potato dextrose agar (PDA) and nutrient agar (NA), using seven products at two application rates. All products inhibited the mycelial growth of C. cassiicola, with greater efficacy observed for Reverb®, Bombardeiro®, and Provilar® (>50% inhibition). In general, inhibition was higher on PDA, with no consistent differences between application rates. Under greenhouse conditions, the products were applied preventively, one day prior to pathogen inoculation on cucumber plants. Disease severity, as well as the number and area of leaf lesions, were evaluated at five and ten days after inoculation. All products reduced target spot severity at ten days, with Serenade® and Caravan® showing the best performance. Additionally, Bombardeiro® and Restrict® at the lower rate, and Frontier® and Provilar® at the higher recommended rate, were effective, generally associated with a reduction in lesion number. Overall, the results highlight the potential of Bacillus-based microbiological fungicides for the preventive management of cucumber target spot, representing a promising and more sustainable alternative to chemical control.