The objective of this study was to determine the agronomic performances, yield and nutritional quality of lablab cultivars grown under irrigation condition in lowland altitude of Humbo district, Wolaita Zone. The experiment was conducted from December 2016 to April 2017. The field experiment was laid out in a randomized complete block design (RCBD) with four replications. The cultivars tested were Rongai, Highworth and Red during dry season using supplementary irrigation. Yield and yield parameters were recorded at 45, 60, 75 days of age and at 50% flowering stage. The results showed that there were significant differences (p <0.05) among the tested cultivars in terms of whole fresh biomass yield, dry matter yield and yield components. Fresh biomass yield of whole, leaf and stem were consistently higher (p < 0.05) in Rongai compared with Red cultivar at 45, 60, 75 days and 50% flowering stage. Likewise, fresh biomass in terms of whole yield, leaf and stem yield of Red Labalab cultivar was higher (p < 0.05) compared to Highworth. The leaf: stem ratio was higher (p < 0.05) in Red cultivar only at 50% flowering stage. The highest DM content of whole, leaf and stem yield was obtained in Rongai while the lowest in Highworth at 45, 60, 75 days and at 50% flowering. In conclusion, Rongai and Red cultivars had better biomass yield than Highworth. In terms of Chemical composition and digestibility, the highest ADF (25.9%) and IVDMD (68.5%) were found in Red cultivar while the lowest was observed in Rongai cultivar. The ash, CP, NDF and ADL contents were similar among cultivars (p > 0.05). Result from this study suggest that Rongai could be introduced for better fresh and dry matter yield (t ha1) for strategic supplementation of ruminants in lowland areas and similar agro-ecologies where legume option is limited. However, for those who has interest for high seed production, Highworth could be recommended.

Keywords: Highworth, Lablab cultivars, Nutritive value, Red, Rongai