Effectiveness of rhizobia strains isolated from South Kivu soils (Eastern D.R. Congo) on nodulation and growth of soybeans (Glycine max)

Ndusha, B.N., Karanja, N.K., Woomer, P.L., Walangululu, J., Mushagalusa, G.N. and Sanginga, J.M.

The identification of effective local Bradyrhizobium strains that nodulate with Soya has as a goal the development of a production industry of the inoculants using the strains adapted to local conditions. This study was carried out at the IITA Kalambo station and aims to select the effective local strains that nodulate soya in the soils of South Kivu. 107 isolates were collected from legume nodules and tested under sterile conditions in the greenhouse, using as substrate sterile sand in modified Leonard jars. Each seed was inoculated with 1 ml of concentrated culture at 109 cells per milliliter. Only 10% of these isolates produced a high number of nodules and a high aerial biomass weight (p˂0.001) compared to the USDA110 commercial strain and were selected to be tested in 3L capacity pots using the soils of the fields as substrate in the greenhouse. Each pot was also inoculated with 1 ml of isolate. Of the strains tested, only six produced a high number of nodules and a high biomass weight compared to the native strains but also to the USDA110 commercial strain. These strains were therefore considered effective and competitive. These strains are: NAC10, NAC22, NAC37, NAC67, NAC40 and NAC75. Each time the strains produced a large number of nodules there was also a high weight of biomass. Keywords: Effectiveness, indigenous Rhizobium, Selection, Soybean, South Kivu.

Int Scholars journals: African Journal of Soil Science