ARBUSCULAR MYCORRHIZAL FUNGI STATUS OF SOME CROPS IN THE CROSS RIVER BASIN OF NIGERIA

The incidence of arbuscular mycorrhizal fungi (AMF) colonization and rhizospheric spore prevalence of ten crops was studied in relation to their foliar concentration of nitrogen, phosphorus and potassium in the Calabar area of the Cross River Basin of Nigeria in order to determine their mycorrhizal status. All crops studied had an incidence of mycorrhizal colonization including Talinum triangulare, a member of Portulacaceae family. The highest percentage AMF colonization of 97.60% and rhizospheric spore density of 112 spores/5g soil were found in Arachis hypogea, while Talinum triangulare and Telfairia occidentalis had the lowest percentage AMF colonization of 30.90% and rhizospheric spore density of 10 spores/5g soil, respectively. There was no correlation between percentage AMF colonization and rhizospheric spore density of the crops sampled. Foliar phosphorus concentration was highest in A. hypogea, (1.20%), for potassium it was in Colocasia esculenta (9.3%), while T. occidentalis had the highest foliar nitrogen concentration (4.9%). There was no significant relationship between foliar nutrient concentration and AM fungi colonization or rhizospheric spore density.