Fruit waste-derived extracts as natural biostimulants for seed priming in maize and common beans

Seed germination and early seedling vigor are critical for successful crop establishment, especially in stress-prone, resource-limited agroecosystems. This study evaluated aqueous extracts from overripe/spoiled papaya ( Carica papaya ), banana ( Musa spp .), lemon ( Citrus limon ), and pineapple ( Ananas comosus ) fruits as natural seed priming agents for maize (Zea mays L.) and common bean ( Phaseolus vulgaris L .). Certified seeds were primed for 4–6 h with 1:4 (v/v) diluted extracts and compared with distilled water (control) under laboratory conditions (25 ± 2°C). Papaya and banana extract significantly outperformed other treatments, increasing final germination percentage to 90–94% in maize and bean (vs. 74–76% in controls) and markedly reducing mean germination time. Banana-primed maize seedlings exhibited the longest shoots (14.1 cm) and roots (7.9 cm), whereas papaya-primed bean seedlings reached 13.4 cm and 8.2 cm, respectively. All vigor indices followed the same trend (papaya ≈ banana > pineapple > lemon > control). These low-cost, waste-derived biostimulants therefore represent a sustainable alternative to synthetic priming agents and are particularly suitable for smallholder farming systems in semi-arid regions.