Effect of chemical and biological seed treatments on common bean seeds inoculated with Fusarium oxysporum f. sp. phaseoli

Abstract

ABSTRACT: Currently, the common bean (Phaseolus vulgaris L.) productivity has been reduced by the fungus Fusarium oxysporum f. sp. phaseoli (Fop), the causative agent of Fusarium wilt. Considering the integrated management of diseases, the objectives of the present work were to verify the compatibility between chemical and biological fungicides for Fusarium oxysporum Schlecht. f. sp. phaseoli Kendrick & Snyder (Fop) control in common bean seeds. In laboratory, the effects of the treatments were evaluated by sanity, germination, seedling total length and seedling dry matter tests. In greenhouse conditions, the emergence speed rate, the percentage of emergence and the rate of pathogen transmission through the pathogen infestation in a substrate to plants were evaluated. Common bean seeds BRS Estilo were artificially inoculated with Fop isolate (IAC 11.299-1). In the seeds’ treatment, the chemical fungicides fludyoxonyl, flutriafol, methyl tiofanate, and biological products of Trichoderma sp. (isolates SF04, GF 422 and strain 1306), separately and mixed, were used. Treatments that promoted the best pathogen control in seeds were the combination of methyl tiophanate with biological products. Both flutriafol and GF 422 isolated and in mixed treatments affected the seeds’ physiological quality. The protective effect of the products was noted in the transmission test, whose Fop incidence was from 5 to 40% in the hypocotyl and from 5 to 30% in common bean roots.