Effect of Seed Priming by Ascorbic Acid on Seed Germination and Seedling Growth of Cowpea (Vigna unguiculata L. Walp)

Abstract

Seed priming enhances seedling growth in cowpeas, a crop of nutritional and economic importance. However, its physiological effects, particularly its interaction with antioxidants like ascorbic acid, remain underexplored. We hypothesized that priming cowpea seeds with ascorbic acid would enhance germination percentage, root and shoot length, and seedling biomass. The objective of the study was to investigate the effects of ascorbic acid seed priming on cowpea (Vigna unguiculata L. Walp) germination and seedling growth. An experiment was conducted using a Randomized Complete Block Design (RCBD) with three treatments and three replications. Treatments included three levels of ascorbic acid (0 as control, 0.5, and 1 mM), where seeds were soaked for 12 hours for priming and air-dried for an hour. Each dish contained ten seeds subjected to the respective treatments. The results indicated a significant effect of ascorbic acid priming on germination and seedling growth. The highest germination percentage (100%), shoot length (10.84 cm), root length (9.97 cm), and fresh weight of seedlings (5.60 g) were observed in seeds primed with 1 mM of ascorbic acid. However, the control (0 ascorbic acid) exhibited lower values with 80% germination, shoot length of 6.84 cm, root length of 5.54 cm, and seedling fresh weight of 3.77 g. These findings suggest that ascorbic acid enhances early-stage cowpea growth and improves metabolic activation during germination. Further research is recommended to explore the interaction of ascorbic acid priming with mixed-seed systems and other vegetable crops to determine its broader agricultural applications.