Seed health of common bean stored at constant moisture and temperature

Abstract

Fungal incidence in stored common bean (Phaseolus vulgaris L.) is the main concern in order to preserve seed health and viability. The main aim of this study was to analyse these quality parameters in hermetically stored seeds at 10.2, 13.1, 16.2, 18.5% moisture content (MC) and 25, 30, 35, 40°C, through seed germination and health tests. Water activity recorded at 10.2 and 18.5% MC were 0.448 and 0.700, respectively. Low seed moisture content reduced Alternaria spp. incidence at 25-30°C. Highest incidence of Fusarium spp. (7.5%) occurred at 16.2% MC and 35-40°C. Highest incidences of Rhizoctonia spp. (8-10%) were recorded at 16.2-18.5% MC and 30-40°C. Penicillium spp. and Aspergillus spp. were predominant throughout the experiment and the highest incidences (80-100%; 20-30%, respectively) were scored at 18.5% MC and 30-35°C and 13.1-18.5% MC at 35°C, respectively. The higher the seed MC the higher the fungi incidence while lower seed MC decreased the incidences by 25%. Storage conditions below 30°C and 13.0% MC appear suitable to preserve common bean seed in relation to viability and health, up to a 8-month period.