Abstract:
A greenhouse experiment was conducted at the South Eastern Kenya University (SEKU) to determine the effects of
farmyard manure (FYM) and arbuscular mycorrhiza fungi (AMF) inoculation on growth, vigor, shoot nutrient uptake
(SNU) and AMF root colonization percentage (RC%) of potted Calotropis procera (Calotropis) seedlings. A field trial was
laid out to determine the effects of the treatments on growth and fruit fibre productivity of the transplanted seedlings.
The experiments were laid out in a split-split-plot design with a 2*2*2 factorial arrangement and 3 replications. The
main plot factor constituted 2 Kenyan Calotropis provenances, Kibwezi and Tharaka. The sub-plot factor comprised of
FYM and without FYM application while the sub-sub-plot factor involved inoculation with mixed strains of commercial
AMF and without inoculation. Farmyard manure (FYM) and the integration of FYM and AMF inoculation (FYM*AMF)
significantly improved Calotropis seedlings’ growth, vigor, SNU and AMF RC% in the greenhouse. However, FYM*AMF
was comparatively superior to solely FYM and AMF. There were positive correlations of AMF RC% with growth, shoot
dry weight (SDW) and SNU of the seedlings at the end of the greenhouse experiment. Under field conditions, FYM and
FYM*AMF significantly enhanced growth and fruit fibre productivity of Calotropis plants than the controls, barring a
few cases. The study recommends the use of FYM and FYM*AMF in Calotropis seedlings’ production in the drylands of
Kenya. Future research should investigate the persistence of the introduced commercial AMF strains in the soil using
molecular techniques.
