Effects of Red Guava Extract Seed Priming on Rice Viability and Vigor under Salinity Stress

Soil salinity severely restricts rice establishment by impairing seed germination and early seedling growth. Seed priming with antioxidant-rich natural extracts is a low-cost approach to improve seed performance under saline conditions, although the optimal priming duration and the role of aeration remain poorly understood. This laboratory-based study was conducted from June to September 2021 at the Laboratory of the Faculty of Agriculture, Universitas Tidar, Indonesia, to evaluate the effects of priming duration (6, 12, 18, and 24 h) and aeration (with and without) using 50% red guava (Psidium guajava L.) extract on the viability and vigor of rice cv. Pepe under salinity stress (6 g L⁻¹ NaCl). Each treatment was replicated four times using 100 seeds per replication. A factorial completely randomized design was employed, and data were analyzed using two-way ANOVA followed by LSD tests. Results showed that priming duration significantly affected seed vigor index, root length, and plumule length. Seeds primed for 18 h produced the highest vigor index (74.38%) and showed improved seedling growth compared to other treatments. Aeration showed a significant effect on root length, while showing no significant effect on other observed parameters. No significant interaction between priming duration and aeration was observed. These findings indicate that 18 h priming with red guava extract improved several early seedling performance traits under controlled laboratory salinity conditions. Further studies under field environments are necessary to validate its practical applicability in saline-prone rice cultivation systems.