Agronomical and morphological diversity of the accessions of cassava in Central African Republic

Abstract

Cassava (Manihot esculenta Crantz) is an important subsistence food crop in Central African Republic. Data collections for the agronomical and morphological characterization provided 59 accessions of Cassava and were subjected to multivariate analysis to discriminate groups of accessions according to their morphological features. The Eigenvalues of the principal axes extracted from the multivariate analysis indicated that the first two factors explained 7% of the total variability. Generally, morphological variation of the pool of accessions grown in different cassava production sites largely covers the overall variability and therefore there is no structuring in relation to agro-morphological characters from the sites. The dendrogram established on 59 accessions in relation to agronomical and morphological character is divided into two groups. Group A is the smallest with 12 accessions, while Group B has 47. Most of 59 accessions were different on all 44 descriptors. However, some accessions reported under different names, such as "ICRA and six months", "Boots and Assa", were identical on all the characters. In addition, some accessions collected in different places under one name, such as "Six months," have a likeness of all phenotypic traits.

Occurrence, Distribution and Farmers' Perceptions of Cassava Diseases in Gabon, Central Africa

“…The symptomatologic diagnosis identified five different cassava diseases (mosaic, bacterial blight, anthracnose, leaf necrosis, root rot) in the cassava fields explored, with different levels of mean incidence and mean severity depending on the province. According to Komba and Semballa [30], bacterial and fungal pathologies cause more yield losses when associated with mosaic than alone, as is the case in Gabon. Thus, the low productivity of cassava plantations recorded nationwide and the damage deplored could be linked to the high incidence of cassava mosaic and/or to the combination of viral, fungal and bacterial diseases on cultivated plants, and to a lesser extent, to the incidence of anthracnose.…”