Fungos entomopatogênicos aditivados com quitinase no controle da cigarrinha do milho

• Ano de defesa: 2025
• Autor(a) principal: Rumpel, Vítor Sauzem
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; UFSM; Programa de Pós-Graduação em Agronomia; Centro de Ciências Rurais
• Palavras-chave em Português: Biocontrole; Enzima; Zea mays; Dalbulus maidis; Biocontrol; Enzyme; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA
• Link de acesso: http://repositorio.ufsm.br/handle/1/36872

Maize is an important agricultural commodity, used for both animal and human consumption. This crop is directly linked to meat production and crop rotation, strengthening the agricultural production chain. Among the main challenges faced by this crop are the intensive use of pesticides and the difficulty in controlling the corn leafhopper, the main vector of maize stunt disease complex. The use of bioinputs is a viable alternative to mitigate this issue, through the application of entomopathogenic fungi (EF) supplemented with the enzyme chitinase, aiming to enhance biological control potential. Thus, the objective of this study was to evaluate the efficiency of chitinase addition to fungi in controlling the corn leafhopper. Two experiments were conducted, the first in the teaching-experimental area of the Coxilha Group – UFSM, during the 2023/24 and 2024/25 growing seasons. Ten treatments were applied in a randomized block design with four replicates each: one untreated control, three treatments with isolated EF strains (Metarhizium anisopliae, Beauveria bassiana, and Cordyceps fumosorosea), three with the same EF strains supplemented with chitinase, two with chemical insecticides, and one with chitinase alone. The second experiment was carried out in the laboratory at UFSM, using M. anisopliae, B. bassiana, and C. fumosorosea, with and without chitinase, in a completely randomized design with three replicates each. The evaluated variables were insect counts (population) at three and five days after application (DAA), and the compatibility between EF and chitinase. The treatments that showed the best results in both growing seasons were B. bassiana + chitinase and chitinase alone, with approximately 50% and 40% reductions in populations at three and five DAA, respectively. Regarding colony-forming units (CFU), the EF C. fumosorosea showed the highest CFU count at the 0.1 mL concentration of chitinase. These results highlight the need for further studies to investigate the molecular mechanisms involved in these interactions.