Qualidade sanitária e fisiológica de sementes de araucária durante armazenamento

Abstract

Araucaria angustifolia is a species of ecological and social-economic importance in the southern Brazil region, but it is at risk of extinction. Its seeds are classified as recalcitrant, requiring storage under controlled temperature and humidity to obtain greater longevity. Another aspect is the seed health quality, which is impaired by high seed moisture content that causes fungus proliferation and may reduce germination and seedling quality. The objective of this study was to evaluate the physiological and sanitary quality of araucaria seeds treated with 0.5, 1 and 3 % of sodium hypochlorite (NaClO) and stored at different periods (2, 4, 6, 8 and 12 months). The seed quality was evaluated by germination, vigor and seed health tests. The disinfection of seeds, regardless of the concentration used, temporarily delayed the seed germinations, but did not negatively affect seedling emergence. After 12 months of storage, the seeds showed infection by Schizophyllum commune, which caused the reduction of the germination. The seeds treated with NaClO showed lower fungal incidence, especially Schizophyllum commune, ensuring the seed health quality during storage for 12 months. The treatment with NaClO positively favors the physiological quality of Araucaria seeds that will be stored for a period exceeding four months.