Effect of seed priming on germination, seedling vigour and yield of black gram

Abstract:

Something as simple as soaking seed before sowing turns out to shift black gram's entire germination trajectory rather than just nudging it slightly forward, based on field and laboratory research comparing four pre-sowing seed treatments over two consecutive seasons at Kigali. An untreated control was compared against hydropriming (plain water soak), hormonal priming (gibberellic acid, GA3, solution soak), and bio-priming (Trichoderma-based bio-agent soak), assessing germination percentage, seedling vigour index, and final seed yield. Hormonal priming produced the fastest and most complete germination, reaching 93% cumulative germination by day seven against 68% for the untreated control, and delivered the highest seedling vigour index and seed yield among the four treatments, at 1520 kg per hectare against 1120 kg per hectare for the control, a 35.7% gain. Bio-priming, while producing somewhat lower germination speed than hormonal priming, showed a notable additional benefit in reducing seedling mortality from soil-borne pathogens during the early establishment period, a parameter not directly captured by germination percentage alone. Vigour index component analysis showed root length contributing the largest single share of the vigour gain recorded under priming treatments, ahead of shoot length and seedling dry weight. These findings support hormonal priming as the most yield-effective single intervention among those tested, while highlighting bio-priming's complementary disease-suppression value where soil-borne pathogen pressure is a known constraint, suggesting combined hormonal-biological priming protocols may merit further testing.