Abstract

Seeds are characterized by rapid deterioration during storage under humid tropical conditions of high air temperature and relative humidity. Physiological changes that occur in seeds during storage are manifested as reduction in seedling vigor index, number of germination, percentage germination, speed of germination and rate of germination among others. This study aimed at prolonging the longevity of sesame seed through containerized storage with charcoal desiccant. Forty grams of sesame seeds was stored with varying amount of charcoal desiccant (0, 40, 80, 120, 160 and 200 g). The containerized seeds were then placed in a wooden cabinet with average ambient conditions of 29.8ºC and 80% relative humidity, and stored for 12weeks. Samples were taken from storage at interval of two weeks and tested for seed viability and seedling vigor. Analysis of variance (ANOVA) was carried out on the data collected and treatment means were separated using Duncan’s Multiple Range Test (DMRT). Serial germination data were also subjected to probit analysis in order to model sesame seed deterioration in storage. ANOVA results show that charcoal treatments were highly significant (P≤0.01) on all the seed viability and seedling vigour parameters evaluated. Storage time was also highly significant on all the parameters. However, interaction between seed treatment and storage time was not significant (P≥0.01) on seed germination and seedling vigour index. There were also statistical differences among the charcoal treatments and among the storage periods. Probit results indicate that seed preservation was optimal in seed treated with 200 g charcoal with seed half life (P50) of 13.19 weeks, and lowest seed deterioration rate (1/σ) of 0.1559. It is recommended that 200 g or more of dry charcoal should be adopted for short-term and medium- term sesame seed treatment as it effectively maintained seed viability and seedling vigour during storage as compared to other treatments.