Pre-germination treatments and application of soil amendments for Supa (Sindora supa Merr., Fabaceae)

Through two experiments, this study aimed to determine the optimal pre-germination techniques and soil amendments for Supa. The first experiment tested four pre-treatment techniques: control, soaking in cold water for 12 and 24 hours, and soaking in hot water for 5 and 10 minutes. The second experiment applied different soil amendments to transplanted seedlings: garden soil/control, 2:1 garden soil and cow dung, 2:1 garden soil and chicken manure, 2:1 garden soil and vermicompost, and 2:1 garden soil and sawdust. Both experiments were arranged in a Completely Randomized Design. Results showed that Supa seeds soaked in hot water for 10 minutes (T4) had the highest percentage of germination and germinative energy, while seeds subjected to cold water for 24 hours (T2) had the earliest mean days of emergence. There was no significant difference among treatments for percent germination and germinative energy. Regarding soil amendments, Supa seedlings had a 100% survival rate in all treatments except for chicken manure (T2). The sawdust treatment resulted in the highest increase in root collar diameter, length, and number of secondary roots. In contrast, vermicompost resulted in the highest increase in shoot length, chlorophyll content, and root biomass. The untreated and cow dung treatments resulted in the highest shoot biomass. The different amendments significantly affected all parameters except for the number of secondary roots and root biomass.