Effect of micronutrient seed priming and biopriming on germination and seedling vigour of yard long bean (Vigna unguiculata subsp. sesquipedalis)

Yard long bean (Vigna unguiculata subsp. sequipedalis) is an economically important and nutritionally rich vegetable widely cultivated in Kerala, where its long tender pods form an essential component of local diets. The present study, conducted during 2024-2025 at the Department of Plant Pathology, College of Agriculture, Vellayani aimed to evaluate the effects of seed priming with zinc, boron and biopriming with bioagents i.e. Bacillus amyloliquefaciens VLY24 and Bacillus velezensis PCSE10 in yard long bean under in-vitro conditions. The experiment was laid out in a Completely Randomized Design with seven treatments replicated thrice. Results indicated significant enhancement in germination, shoot length, root length and seedling vigour due to both priming and biopriming treatments. Maximum shoot length (17.49 cm) was observed in seeds bioprimed with B. amyloliquefaciens VLY24. The highest root length (20.87 cm) and germination percentage (90%) were recorded in zinc primed seeds. Borax priming also improved germination and root development. Seedling Vigour Index-I was highest in Carbendazim treated seeds (3378.85), followed by ZnSO₄ priming (3272.23) and B. amyloliquefaciens biopriming (3136.58). From the study integrating micronutrient priming ZnSO₄ and microbial biopriming effectively enhances early seedling growth and vigour. These approaches offer promising, eco-friendly strategies for establishing a strong crop stand and improving the sustainable production of yard long bean.