Main Article Content
Composition of arbuscular mycorrhizal fungi associated with cassava (Manihot esculenta Crantz) cultivars as influenced by chemical fertilization and tillage in Cameroon
Abstract
Objectives: Arbuscular mycorrhizal fungi (AMF) form root symbiotic relationships with higher plants, but their abundance and symbiotic effectiveness may be influenced by agricultural practices. This study investigated the effect of N-K fertilization and tillage on soil’s AMF composition and root colonization of some selected cassava varieties in Eastern and Southern Cameroon.
Methodology and results: Three cassava varieties were grown in Eastern Cameroon in tilled and non-tilled plots. In Southern Cameroon, five varieties were grown in non-tilled plots, with half of them receiving NPK (10-10-20) fertilization. Collected soil and root samples were analyzed to quantify and describe the AMF communities. AMF root colonization was 35% regardless to the variety and farming system in Eastern region, while it reached 45% in Southern Cameroon. Root colonization varied among varieties within and between locations. Fertilized plots displayed lesser microbial density than non-fertilized plots and the tillage highly reduced the root colonization as well as the density of spores.
Conclusions and application of findings: In Eastern and Southern parts of Cameroon, the identified AMF communities in a symbiotic relationship with cassava were ascribed to the three genera Glomus, Gigaspora and Acaulospora. Among these three genera, Glomus was predominant in all the sites; indicating its wide geographical distribution in Cameroon and affinity with cassava. Species of the genus Glomus may therefore be used during mycorrhizal inoculations of cassava. However, AMF root colonization varies in relation to the variety type and the environment; with the southern region of Cameroon showing the higher colonization levels. This study revealed that to obtain higher AMF spores densities in soil and maximize root colonization, cultivation systems with a lesser soil disturbance and fertilization is recommendable in cassava cultivation.
Keywords: Arbuscular mycorrhiza funji (AMF), Cameroon, Cassava cultivation, Chemical fertilization, Tillage