Abstract:
Arbuscular Mycorrhizal Fungi (AMF) are naturally occurring root symbionts known to improve
the uptake of essential nutrients by host plants due to their extra-radical hyphae. However, the
effect of indigenous AMF inoculation on the growth of papaya hybrids has not been
investigated. This study evaluated the effect of AMF inoculation on the growth characteristics
of papaya hybrids (JKUAT and Malkia) at the vegetative stage. A greenhouse experiment
consisting of three treatments—AMF inoculum, compost manure, and a combination of
inoculum and compost manure—was set up in a completely random design and replicated six
times. Non-treated seedlings were included as controls. Spores were isolated from
rhizospheric soil samples and bulked in a potted sorghum crop for four months to obtain AMF
inoculum. The treatments were applied to papaya seedlings between the second and third leaf
stages. Growth parameters including plant height, leaf length, stem girth, and number of
leaves were recorded every 4 weeks for a period of 20 weeks after planting (WAP). All data
were subjected to one-way ANOVA at the p ≤ 0.05 level, with significant and nonsignificant
means separated using Tukey's HSD test in Genstat's 15th edition. Results showed that plants
treated with a combination of compost manure and AMF inoculum were significantly different
(p ≤ 0.05) for all growth parameters tested, compared to compost manure alone and the
control treatments. Malkia hybrids treated with a combination of compost manure and AMF
inoculum (MIC) had the highest plant height of 53.2 cm at 20 WAP. JKUAT hybrids treated with
AMF inoculum and composted manure and the control treatment had a root biomass of 49
and 11.80 grammes at 20 WAP, respectively. In conclusion, soil media amendment with
compost manure and AMF inoculum enhanced overall papaya seedling growth, and the growth
response was dependent on papaya hybrids.
