Enhancing Lettuce Seed by Pelleting and Packaging Techniques

This study developed a seed pelleting method using natural and bio-based materials and an effective post-pelleting storage strategy to improve the performance of small-sized seeds with limited internal nutrient reserves. Lettuce (Lactuca sativa L.) was used as a model crop. Organic filler materials consisting of diatomaceous earth (DE) combined with bat granular (DE+BG) and DE combined with solid vermicompost (DE+SVC) were evaluated. Furthermore, binding solutions were prepared from gum arabic supplemented with Streptomyces sp. crude extract at 0, 5, 50, and 500 ppm. Non-pelleted seeds were the control. The optimal natural- and bio-based pelleting formulation was subsequently stored with activated clay as a moisture-adsorbing material under ambient and cold conditions for 6 months. Results found that the DE+BG contained higher macronutrient levels (N 2.7%, P2O5 1.4%, K2O 1.0%) than DE+SVC and significantly improved shoot growth under both laboratory and greenhouse conditions without affecting germination. The binders combined with the 500 ppm crude extract significantly enhanced seedling vigor, photosynthetic performance, phytochemicals, and increased biomass accumulation (p < 0.05) in the plant. Importantly, packaging the seed pelleted with activated clay and storing it under cold conditions effectively maintains seed germination and seedling performance during storage. These findings demonstrate a novel integrated natural- and bio-based pelleting and storage approach that enhances early seedling growth and preserves seed quality during storage.