Gicharu et al
Greener Journal of Agricultural Sciences Vol. 3 (11), pp. 748-754, November 2013.
ISSN: 2276-7770 © 2011 Greener Journals
Manuscript Number: 110913839
Variation in Nitrogen Fixation among Three Bush Bean Cultivars Grown in Kenya when Inoculated with Three Rhizobia Strains
Gibson Kamau Gicharu1, Nkanata Mburugu Gitonga2,
Hamadi Boga3, Richard Chelule Cheruiyot4 and
John M. Maingi4*
1Department of Pure and Applied Sciences, Technical University of Mombasa, Mombasa, Kenya.
2 Meru University of Science and Technology, Meru, Kenya.
3Department of Botany, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
4Department of Plant and Microbial Sciences, Kenyatta University, Nairobi, Kenya.
*Corresponding Author’s Email: maingijohn @ gmail.com
Nitrogen deficiency is a major factor limiting bean
production in Africa. This problem can be alleviated by the
use of nitrogen fertilizers which on the other hand
adversely affect the environment. The problem can also be
alleviated by the use of environmental friendly biological
nitrogen fixation technology. In this study, growth
experiments were designed to investigate biological nitrogen
fixation in three determinate (bush) beans namely Ayenew,
GLP 24, and Ecab 0807. Greenhouse and field studies were
carried out to determine the most efficient bean cultivar
and rhizobia strain in nitrogen fixation. Each bean cultivar
was inoculated with the rhizobia strains CIAT 899, USDA
2674, USDA 2676, the three rhizobia strains combined and one
was not inoculated. Results from greenhouse studies showed
significant statistical differences in nodulation within the
bean cultivars. The bush bean cultivar GLP24 was poorly
nodulated (40.0 nodules on average) as compared to Ayenew
(52.0 nodules on average) and Ecab 0807 (58.0 nodules on
average). It was also observed that bush beans inoculated
with USDA 2674 strain of rhizobia in the greenhouse produced
the highest nodule number although in the field, it was
those inoculated with strain CIAT 899. Bush beans inoculated
with USDA 2674 gave the highest total plant dry weight.
Treatments within each of the cultivars showed differences
in total plant dry weight yield in response to rhizobia
strain used. Field experiments showed that plant dry weight
differed statistically between cultivars at P<0.05. Bush
beans inoculated with USDA 2674 gave the highest total plant
dry weight but there were no significant differences in
Keywords: Bush beans; Rhizobium; Nitrogen fixation, Central Kenya.