Effect of seed biopriming treatments on germination, seedling growth, and vigour of Vigna radiata (cv. CO-8) and Vigna unguiculata (cv. Bundel Lobia-1)

The present study evaluated the impact of seed invigoration treatments using Rhizobium-based bio-priming on germination, seedling growth, and vigour in greengram (Vigna radiata cv. CO-8) and cowpea (Vigna unguiculata cv. Bundel Lobia-1). Seeds were subjected to eight treatments: untreated control (T1); hydropriming with distilled water (T2); TNAU Rhizobium at 15%, 20%, and 25% concentrations (T3, T4, and T5); and GRI laboratory isolated Rhizobium at 15%, 20%, and 25% (T6, T7, and T8), respectively. The roll towel method was employed under controlled laboratory conditions at the Genetics and Plant Breeding Laboratory, School of Agriculture and Animal Sciences, The Gandhigram Rural Institute, Dindigul, Tamil Nadu, India. The results indicated that TNAU Rhizobium at 20% concentration (T4) significantly improved germination rates (100%), shoot length (23.5 cm), root length (16.6 cm) and vigour index I (3741) in Vigna radiata cv. CO-8. In cowpea, TNAU Rhizobium at 15% (T3), which demonstrated a germination rate of 96.66%, fresh weight (2.98 g), dry weight (0.22 g), and root length (18.5 cm). However, the TNAU Rhizobium 15% (T5) demonstrated significantly higher shoot length (28.4 cm) and vigour index I of 4349.17 in Vigna unguiculata cv. Bundel Lobia-1. Seed bio-priming with Rhizobium strains at optimal concentrations significantly enhanced seedling biomass and vigour indices relative to control and hydropriming treatments. This research demonstrates the efficacy of Rhizobium-based biopriming as a pre-sowing treatment to improve seed quality traits in pulse crops.