Impact of drying methods and moisture content on viability of vegetable seeds during storage

Abstract:

Think of seed drying the way you’d think of preserving fruit: get the moisture wrong, and what looked perfectly fine at harvest turns worthless a few months later. This research evaluated how three drying methods (sun drying, shade drying, and mechanical drying at 35 °C) and three initial moisture levels (12%, 10%, 8%) influenced the germination, vigour, and storability of four vegetable seed types — tomato, okra, brinjal, and bottle gourd — over 12 months of ambient storage at Kanpur and Bhubaneswar. Mechanical drying to 8% moisture content maintained the highest germination across all species at 12 months (86.4–92.7%), outperforming sun drying (64.8–76.3%) by 18–22 percentage points. Shade drying to 8% was intermediate. Vigour index followed the same ranking. Seed-borne fungal incidence was lowest in mechanically dried seeds (3.2–5.1%) and highest in sun-dried lots (11.4–18.7%). These results confirm that controlled mechanical drying to ≤8% moisture is the most reliable method for maintaining vegetable seed quality during storage under subtropical Indian conditions.