Germination and storage of Trema cannabina seeds

Storage behaviour and germination enhancement of Trema cannabina seeds (Ulmaceae) were studied. Freshly harvested mature seeds germinated to about 70% in 12 weeks at 30/20°C alternating temperatures. Moist stratification at 4°C prior to incubation of fresh seeds significantly increased germination rate and the mean germination time decreased from 53 days to 23 days in 2 months, and to 17 days in 5 months. Immersing seeds in concentrated sulphuric acid for 80-90 minutes significantly increased germination percentage and rate. Seeds of T. cannabina survived desiccation to both 4.9% and 9.6% moisture contents (MC) (fresh weight basis) and storage at 4 and 15°C, respectively, for 24 months without a loss of germinability, whereas those that were desiccated to 14.4% and 16.2% MC lost their germination from 65% to 0-35% under the same storage condition and period. Seeds stored at −20°C with 4.9% and 9.6% MC drastically reduced their germination from 65% to below 10% in one year and seeds at the same subzero temperature with 14.4% or higher MC did not survive in one month. Thus, T. cannabina exhibited intermediate seed storage behaviour.