Effectiveness Of Rhizobia Strains Isolated From South Kivu Soils On Growth Of Soybeans (glycine Max).
Abstract
Identification of effective indigenous Bradyrhizobium strains which nodulate soybean varieties
could trigger development of an industry for inoculant production with use of strains adapted to
local conditions. This study was conducted in South Kivu to identify and select effective
rhizobial strains nodulating soybean present in South Kivu soils. One hundred and seven isolates
from root nodules of legumes plants sampled in five villages of South Kivu were tested in sterile
sand in the greenhouse in the modified Leonard’s jars. 10% of these isolates produced higher
nodules and plant shoot dry weight (P˂0.001) compared to the commercial strain USDA110 .The
effectiveness index of the isolates NAC10, NAC22, NAC37, NAC40, NAC42, NAC45, NAC46,
NAC50, NAC67 and NAC75 was higher compared to the commercial isolates and were selected
for further evaluation using soils in the greenhouse. From the potted soils experiment in the
greenhouse the isolates NAC10, NAC22, NAC40 and NAC75 were classified as competitive and
highly effective. Increments in nodule number and shoot dry weight were observed when the
plant was inoculated with an effective rhizobial isolate compared to the controls. the best strains
were tested also for carbon source utilization ability. Three sources of carbon were used namely
mannitol, glucose and glycerol. From this experiment there was significant differences between
the three carbon sources in sustaining viable counts of the tested isolates from South Kivu soils
(P<0.005) with higher carbon substitution index with the glucose.
Citation
Ndusha,B.N.,2014.Effectiveness Of Rhizobia Strains Isolated From South Kivu Soils On Growth Of Soybeans (glycine Max),A Thesis Submitted In Partial Fulfilment Of The Requirements For The Degree Of Master Of Science In Sustainable Soil Resource Management, Department Of Land Resource Management And Agricultural Technology (larmat), Faculty Of Agriculture, University Of Nairobi.Publisher
University Of Nairobi