1Department of Biochemistry, Kenyatta University, Microbiology and Biotechnology, 43844-00100, Nairobi, Kenya.
*Corresponding Author: Valentine Mburu, Department of Biochemistry, Kenyatta University, Microbiology and Biotechnology, 43844-00100, Nairobi, Kenya. Email: varadneymburu@gmail.com
The cultivation of cowpea in Sub-Saharan Africa plays a crucial role in enhancing food security for the region’s growing population, while also enriching the soil with vital nutrients such as nitrogen (N) through biological N fixation. However, current cowpea production falls far below its estimated potential. Additionally, a large percentage of cowpea is grown by smallholder farmers who face challenges such as poor soil fertility, low N levels and low yields. Therefore, this study aimed to investigate the effect of native rhizobia inoculation on field-grown cowpea and its cross-inoculation potential on common bean (Phaseolus vulgaris).
A field experiment was conducted based on randomized complete block design (RCBD) with three cowpea varieties and four treatments: indigenous rhizobia, comsmercial rhizobia, a consortium of both and an uninoculated control. Native rhizobia were isolate from root nodules in control plots, characterized morphologically and biochemically and identified via Sanger sequencing. These isolates were then cross- inoculated onto two common bean varieties in a greenhouse RCBD.
Isolated rhizobia differed genetically across regions and included various Rhizobium species. Cross-inoculation significantly increased root dry weight, shoot dry weight, nodule number and nodule dry weight in common bean (p<0.05). Native rhizobia showed a strong potential as sustainable biofertilizers for improving legume productivity across varying climatic conditions.
Biofertilizer, Common bean (Phaseolus vulgaris), Cowpea (Vigna unguiculata), Cross-inoculation, Native rhizobia
