Effect of Pongamia pinnata Leaf Extract as a Priming Agent on the Growth and Development of the Spinach (Spinacia oleracea)

Seed priming is an effective technique to enhance seed germination, seedling vigor, and crop productivity. This study investigates the effects of Pongamia pinnata leaf extract as a natural priming agent on the growth and development of spinach (Spinacia oleracea). Spinach seeds were primed with the extract and compared with non-primed control seeds through laboratory and field trials. Laboratory tests assessed germination percentage, speed, and uniformity on germination sheets, while field trials measured agronomic traits including germination rate, plant height, no of leaf, leaf surface area, leaf length and width and yield traits at 30, 45, and 60 days after sowing (DAS). Results showed that seed priming with Pongamia pinnata extract significantly improved germination rate and seedling uniformity. Primed seeds demonstrated faster and more consistent germination, while the resulting plants exhibited enhanced vegetative growth, including greater plant height, larger leaves, increased leaf area, and improved root development. Additionally, foliar application of the extract at 15-day intervals post-germination further boosted plant growth, indicating a synergistic effect of priming and foliar spraying. This study concludes that Pongamia pinnata leaf extract is an eco-friendly, sustainable alternative to synthetic treatments, promoting early plant establishment and sustained growth. Its dual application through priming and foliar spraying holds potential for improving spinach cultivation, with broader agricultural applications warranting further research.