Symbiotic effectiveness of Elite rhizobia strains on productivity of improved chickpea (Cicer arietinum l.) Varieties. Case of Debre zeit and Wolayta sodo, Ethiopia.

Chickpea (Cicer arietinum L.), is a multi-functional crop with important role in the diet as affordable protein source and in sustaining soil fertility through nitrogen fixation. However, its productivity in Ethiopia of 1.9 t ha-1 is lower than its potential of 5.5 t ha-1 under well managed conditions, partly due to soil fertility limitations. The study was designed to evaluate effectiveness of elite rhizobia strains on productivity of improved chickpea (cicer arietinum L.) varieties at Debre Zeit and Wolayta Sodo, Ethiopia. The experiment was conducted at two sites, Debre Zeit (8.73° N, 38.97° E, 1900 m.a.s.l) and Wolayta Sodo (7.04° N, 37.2° E , 1880 m.a.s.l) using three chickpea verities (Natoli, Teketay and ICC-4918) with four levels of rhizobia strains (three indigenous and one commercial inoculants) and one control (non inoculated treatment) arranged in split plot design with three replications. Chickpea varieties as main plot and the rhizobial inoculants as sub plots were assigned to experimental unit randomly. To measure the response of chickpea against the treatments, data were collected on various symbiotic, phenological and yield and yield related traits of chickpea and subjected to statistical analysis using linear mixed model. Inoculated plants produced significantly (p<0.05) most of symbiotic, grain yield and yield related traits than non-inoculated treatments. Shoot nitrogen yield was increased in the range of 13.0 – 31.34% by inoculation with strain ICRE-025 over the two test sites. The highest level of N fixation was achieved in genotype ICC-4918 by inoculation with EAL-029 and ICRE-025 which entails that the genotype is of good nitrogen assimilator. Similarly, inoculation enhanced grain yield by 17 - 42%, over control treatment. The highest level of grain yield improvement was achieved by inoculation of chickpea variety with ICRE-05 (42%) and ICRE-03 (36%) at Debre Zeit and Wolayta Sodo respectively. In general, depending on the type of chickpea variety used yield improvement in the context of this finding additional 314 – 1252 kgha-1 chickpea grain yields would be produced due to rhizobial inoculation. Investigations at both test sites demonstrated that inoculation of chickpea varieties with native rhizobial strains were effective and useful for optimized chickpea production.