Effect of Productive Tillers on Seed Yield and Seed Quality of Sorghum (Sorghum bicolor L.) Varieties in Assosa District, Western Ethiopia

Poor management of sorghum tillers is a significant problem in the Benishangul-Gumuz region of Ethiopia, affecting seed yield and quality. An experiment was conducted to determine the impact of sorghum productive tillers on seed yield and quality. The study involved two Sorghum varieties (Assosa-1 and Adukara) and three plant types per spot. The treatments were aligned as RCBD and CRD in factorial combination, replicated three and four times for field and laboratory experiments respectively. Varieties influenced TSW (P < 0.0001), Number of tiller influenced by number plants head matured for seed production (P ≤ 0.0001), plants height (P ≤ 0.0004), The interaction effects of varieties and number of tillers per plant influenced yields, Panicle length (P < 0.0001). For laboratory experiments varieties influenced Speed of germination (P < 0.0001), number of Dead seeds (P < 0.0001). Number of tiller influenced Speed of germination (P < 0.0001), number of Dead seeds, shoot length (P < 0.004), Vigor index one and Vigor index two (P≤0.05). The interaction effects of varieties and number of tillers per plant influenced Standard germination (P < 0.001). The main shoot plants had the highest number of fertile sorghum heads (86.5), followed by primary tillers (27.08). Secondary tillers had the highest plant height (96.52 cm). The main shoot plant yielded more seeds than primary and secondary tillers, with the shoot exceeding these yields by 302.96% and 1333%, respectively. Primary and secondary tillers had higher percentages of dead seeds than the main shoot plant, 53.5% and 45.2%, respectively. The primary and secondary tillers experienced a decline in seedling vigour index one over different periods, while the main sorghum plant varieties, Adukara and Assosa-1, showed an upward trend. The germination percentages of the primary and secondary tillers were less than the 85% Ethiopian seed standard requirement. Because sorghum tillers lower seed quality, they should be eliminated for seed production. If sorghum is grown for grain production, secondary tillers have the benefit of raising overall yield production.