Incidence of fungal species in stored soybean seeds in relation to cooling before packing and to packing material

Abstract

Maintaining seed quality during storage is a fundamental premise for production efficiency. The aim of this work was to evaluate the effect of cooling prior to packing seeds and of types of packaging on the occurrence of fungal species and the oscillations of these fungal populations over the storage period of soybean seeds. A completely randomized experimental design was used with four replications in a 2×3×5 factorial arrangement, consisting of cooling or no cooling of the seed mass before packing, three types of packaging materials, and five moments of evaluation during storage. Sanitary quality was evaluated by the method of incubation in filter paper without freezing. The seed mass cooled to 13°C prior to packing returned to ambient temperature in 15 days in a warehouse without controlled conditions. Cooling prior to packing does not affect the sanitary quality of soybean seeds during storage, whereas the type of packaging material does have an effect. The incidence of Phomopsis spp. and Fusarium spp. at the beginning of storage was lower mainly for seeds stored in the high-density polyethylene (HDPE) container. The occurrence of Cercospora kikuchii in both packaging types decreases over storage time. In all the packaging, the incidence of Aspergillus spp. and Penicillium spp. increases along the storage period.