Alternative treatments in bean seeds for repelling Acanthoscelides obtectus (SAY)

Portuguese. Resumo: Objetivou-se avaliar os tratamentos com produtos alternativos na repelência do caruncho do feijão e na qualidade fisiológica de sementes de Phaseolus vulgaris. Utilizou-se delineamento experimental inteiramente casualizado, com quatro repetições, em esquema bifatorial (10x4). Os 10 tratamentos foram: Piper nigrum, diatomáceas e caulim (4 g/kg de semente); Cinnamomum zeylanicum, Citrus sinensis e cinza de Eucalyptus sp. (1% do peso de semente); óleo de Azadirachta indica (3 mL/kg de semente); Gastoxin (6 g/t semente); garrafa pet; testemunha; e quatro períodos de armazenamento (0, 25, 50 e 75 dias). Foram avaliadas as variáveis umidade, germinação, velocidade de emergência, tempo médio de emergência, peso de mil sementes, sementes infestadas e repelência. Os tratamentos com caulim e A. indica foram repelentes no início do tratamento, porém perderam a eficácia ao final do armazenamento. Os produtos a base de C. zeylanicum e Eucalyptus sp. não foram repelentes no início do tratamento, porém o foram no final do armazenamento. Já os produtos a base de C. sinensis e diatomáceas foram repelentes tanto no início quanto no final do armazenamento. Os tratamentos com diatomáceas, caulim, P. nigrum, C. zeylanicum, Eucalyptus sp., A. indica e a embalagem pet são eficientes em reduzir a infestação do caruncho sem impactar negativamente na qualidade fisiológica das sementes.

English. Abstract: The objectives of this study were to evaluate treatments with alternative products for repelling bean weevils, and to assess their influence on the physiological quality of Phaseolus vulgaris seeds. The experiment was carried out in a completely randomized design, with four replications, in a two-factorial scheme (10x4). It comprised 10 treatments: Piper nigrum, diatomaceous earth and kaolin (4 g/kg of seed); Cinnamomum zeylanicum, Citrus sinensis and Eucalyptus sp. (1% of the seed weight); Azadirachta indica oil (3 mL/kg of seed); Gastoxin (6 g/t of seed); PET container; control; and the storage times of 0, 25, 50, and 75 days. The variables seed moisture content, germination, emergence speed, mean emergence time, weight of one thousand seeds, seed infestation, and repellency were evaluated. The treatments with kaolin and A. indica had a repellent effect at first, but they lost effectiveness by the end of the storage period. The products based on C. zeylanicum and Eucalyptus sp. did not have such impact during early periods of storage, albeit repellency grew with time. On the other hand, C. sinensis and diatom-based products were repellents, both at the beginning and at the end of storage. The treatments with diatomaceous earth, kaolin, P. nigrum, C. zeylanicum, Eucalyptus sp., A. indica, and PET container all proved to be effective in reducing bean weevil infestation, without negatively impacting the physiological quality of the seeds.