EFFECT OF STORAGE DURATION ON SEED VIABILITY OF SURI SORGHUM VARIETY HARVESTED FROM CROPS APPLIED ZnSO₄ AT DIFFERENT GROWTH STAGES

Abstract

Sorghum (Sorghum bicolor [L.] Moench) is a potential food crop for marginal lands. Seed viability tends to decline during storage. Zinc (ZnSO₄) application at certain growth stages is expected to increase Zn content in seeds and activate the Cu-Zn-SOD antioxidant enzyme, thereby slowing seed deterioration. This study aimed to determine the effects of ZnSO₄ application at different growth stages, storage duration, and their interaction on the viability of Suri sorghum seeds. The study was conducted at the Seed and Plant Breeding Laboratory, Faculty of Agriculture, University of Lampung. The experiment was arranged in a Randomized Complete Block Design (RCBD) using a split-plot in time arrangement with four replications. The first factor was the timing of ZnSO₄ application (control, vegetative stage, and generative stage), while the second factor was storage duration (0, 2, 4, 6, 8, 10, and 12 months) at room temperature of 27.9 ± 0.5°C. The results showed that ZnSO₄ application at the generative stage resulted in the highest germination speed of 20.66% per day and the highest total percentage of normal seedlings of 64.57%. Storage duration had a highly significant effect on all observed variables. Seed viability remained relatively high for up to six months of storage, then declined during storage from eight to twelve months. A significant interaction was observed between ZnSO₄ application and storage duration, with application at the generative stage showing relatively slower seed deterioration for up to six months of storage.