Longevity of pepper (Capsicum annuum) and watermelon (Citrullus lanatus) seeds in relation to seed moisture and storage temperature

An experiment was conducted for 18 months to observe changes in the longevity of pepper ( Capsicum annuum L.) and watermelon [Citrullus lanatus (thunb) Matsum & Nakai] seeds. Seeds were stored at 10 and 20degreesC, with 8, 10, 12, and 14% moisture contents for 18 months. Total germination, at day 3, emergence percentage and conductivity tests were carried out in samples taken every 3 months. At both storage temperatures, seeds that stored 8-10% moisture contents maintained high viability (greater than or equal to80%) up to 18 months. At higher moisture levels (12-14%) reduction in total germination (44 and 67% in pepper, 82 and 67% in watermelon at 14% for 10 and 20degreesC), germination at day 3 (by the 9th month it was 0% in pepper and varied between 1 and 65% in watermelon) and emergence (between 30 and 50% in pepper and between 38 and 77% in watermelon) was observed. Conductivity tests did not give consistent readings with changes in viability and emergence. Pepper seeds with 8 and 10% and watermelon with 8 and 14% of moisture could be stored at room temperature (20degreesC) for up to 18 months. This was at greater than or equal to70-75 air relative humidity for these species.