EFICIÊNCIA DE FUNGOS ENTOMOPATOGÊNICOS ASSOCIADOS OU NÃO, A ÓLEOS VEGETAIS NO MANEJO DE TRIPES (Caliothrips sp.) NO FEIJOEIRO COMUM

Abstract

Common bean (Phaseolus vulgaris) is a crop of great economic and social importance in Brazil, ranking as the fifth most produced grain, with an estimated 2.9 million tons in the 2021-2022 harvest. However, cultivation faces significant challenges, particularly due to the incidence of pests such as thrips Caliothrips sp., which negatively impacts both the quantity and quality of production. These insects feed on the plant's sap, causing visible damage such as deformed leaves and necrosis, compromising the health of the crops. To mitigate these losses and reduce dependence on synthetic pesticides, alternative pest control is essential. The use of biopesticides, which include vegetable oils and entomopathogenic fungi, emerges as an effective and sustainable approach. Castor oil, orange oil, garlic oil, and citronella oil exhibit insecticidal properties that can aid in managing Caliothrips sp. Additionally, fungi like C. javanica and B. bassiana have shown efficiency in biological control by penetrating the cuticle of insects and proliferating within their bodies. This study evaluated the effectiveness of entomopathogenic fungi, with or without the addition of vegetable oils, in managing thrips Caliothrips sp. on common bean. Two experiments were conducted in a greenhouse and two in field conditions during the vegetative and reproductive phases of the bean plant. In each experiment, treatments were applied, and mortality evaluations were conducted 24 hours, 7 days, and 14 days after application. In the vegetative phase, garlic oil at 5% showed a high initial mortality rate; however, its lack of residual effect limits its long-term applicability. In contrast, castor oil at 2% combined with C. javanica demonstrated robust control, suggesting that entomopathogenic fungi can enhance mortality over time. In the reproductive phase, the treatment with castor oil at 2% + tween + C. javanica stood out for its high effectiveness, indicating that the combination of biological agents with essential oils is an effective strategy for pest management. Orange oil at 2% also showed promising results, especially when associated with B. bassiana, reinforcing the importance of the residual effect of these combinations. A possible synergism was observed between castor and orange oils with fungi C. javanica and B. bassiana. However, further laboratory studies are necessary to confirm this result and investigate the cause of this synergism. The findings of this study may support farmers by providing relevant information on integrated management of thrips in their crops.