Evaluation of growth characteristics of selected beauveria bassiana islolates under laboratory conditions in Kenya

Abstract

An evaluation of the growth characteristics of nine B. bassiana isolates was conducted under
laboratory conditions. Tests for spore concentration, viability, germination percentage,
relative hyphal growth and speed of conidial germination were done. Isolate J59 showed the
highest spore concentration of 120 and 114.2 spores per ml during the first and second assay
respectively. Isolate J57 had the most viable number of spores in both assays. The highest
germination percentage of over 80% was recorded for isolate J57. The relative hyphal
growth was highest for the isolateRI under 6 days after inoculation followed closely by
isolate J57 in both assays. In all the observed days, isolates BBC and BVT recorded the
lowest relative hyphal growth but highest conidial germination at 2 to 10 hours after
inoculation. Evaluation of growth is an important prerequisite for evaluation when
considering the B. bassiana isolates for control of storage pests.