Effects of Media and Fungicide on Seed Germination and Early Seedling Growth

This project tested the effects of media composition and fungicide application on the propagation of 3 native forest species for restoration of forest ecosystems on degraded forestland. The effects of 3 media treatments (sand + soil, sand + coconut husk and soil + coconut husk) and two fungicide treatments (application of Captan and no application of Captan) were tested on seed germination percent, germination rate, seedling mortality and growth of 3 tree species indigenous to Doi Suthep-Pui National Park (Sai Yoy or Ficus benjamina, Ta Lo or Schima wallichii and Ma Kok Ha Ru or Spondias axillaris). Seeds were germinated in plastic trays, with seedlings subsequently transferred into black plastic bags 9 inch x 2.5 inch containing a medium of soil:coconut husk:peanut husk 2:1:1. Seedling height was measured twice, 2 weeks after potting, and 3 months thereafter, for calculation of relative growth rate.

Media composition and fungicide had no consistent significant effects on seed germination. Sand + soil was the best medium for reducing early seedling mortality and increasing seedling growth. Fungicide significantly reduced early seedling mortality for most species and in most media. Coconut husk appeared to increase seedling mortality (possibly due to excessive moisture retention encouraging fungi) and its use should be avoided. Based on the results of this project, sand + soil with application of Captan to the soil surface, when seeds are sown and 1 month afterwards, is the most highly reccommended method for germinating seeds of these native forest tree species.