Abstract

Humidity during storage plays an important role in the vigour and germination of rice seeds, especially in high nutritional rice as Tubtim Chumphae (Oryza sativa L. var Indica cv. Tubtim Chumphae). This experiment aimed to study effects of relative humidity during storage on germination and seed vigour of Tubtim Chumphae rice. Rice seeds were stored in a hermetic condition at relative humidity—RH—of 38%RH and 61%RH. Storing at 84%RH was used as a control. The RH was controlled using glycerol solution. The experiment will be performed in completely randomized designs with 4 replicas. Seeds were drawn at 0, 1, 7 days and 3 months after storage for testing namely; direct and indirect seed moisture content, germination and seed vigour using the radicle emergence test. The results of direct method of seed moisture content showed that the Tubtim Chumphae rice seeds took more than 1 week to reach equilibrium moisture content. The equilibrium moisture content of seeds stored in 38%RH, 61%RH and 84%RH were 10.7%, 10.9% and 13.8%, respectively. Storage at high relative humidity (84%RH) extremely reduced germination and seed vigour of Tubtim Chumphae rice. It was also found that the Tubtim Chumphae rice seeds stored for 3 months at the relative humidity of 38 and 61 percent were significantly higher in germination and seed vigour than the control (P ≤ 0.01).