Prevalence of African Mosaic and Morphological Characterization of Cassava (Manihot esculenta Cranz) Varieties in Two Agroecological Zones of Cameroon

Heu Alain *

Higher Technical Teacher’s Training College, Department of Agriculture and Agropastoral, University of Ebolowa, P.O. Box- 886 Ebolowa, Cameroon.

Mboussi Serge Bertrand

Laboratory of Quality Control, University Institute of Technology, University of Douala, P.O. Box- 8698 Douala, Cameroon.

Kone Nsangou Nourou Abdou

Department of Plant Biology, Applied Botanic Research Unit, University of Dschang, P.O Box -67 Dschang, Cameroon.

Dida Lontsi Landry Sylvere

Department of Plant Biology, Faculty of Science, Laboratory of Biotechnology and Environment, Phytopathology, Plant Protection Research Unit, University of Yaounde1, Yaoundé-Cameroon.

Ngoh Dooh Jules Patrice

Department of Biological Sciences, Faculty of Science, University of Maroua, P.O. Box- 814 Maroua, Cameroon.

Ambang Zachee

Department of Plant Biology, Faculty of Science, Laboratory of Biotechnology and Environment, Phytopathology, Plant Protection Research Unit, University of Yaounde1, Yaoundé-Cameroon.

*Author to whom correspondence should be addressed.


Abstract

The objective of this work is to conduct an epidemiological study of African cassava mosaic and to characterize the diversity of local cultivars in circulation in the monomodal and bimodal rainforest zones of Cameroon. Disease-related parameters (incidence and severity index) were studied as well as morphological parameters (plant height, leaflet color, petiole color, lobe length, number of lobes, number of branches, petiole length). The results show that 96 cassava varieties were identified with 89 local varieties and 07 improved varieties. Diseased plants showed a symptom severity index of 1 to 5, which could reduce production by half in the areas considered. The leaf color was dark green, the number of branches was 3, the lobe and petiole lengths were 16.46 and 22 cm respectively, while the number of lobes was 5 the disease incidence for the two agro-ecological zones as a whole is 57.58% for a symptom severity index of 3. The epidemiological study reveals that the desease incidence of both agro-ecological zones was 57.58 % for a symptom severity index of 2 corresponding to 40 %.  In the humid forest zone with monomodal spray the average incidence was 49.74% and a leaf attack rate was 29.03 % in the locality of Njombé (Cameroon's littoral region). At Ekona in southwestern Cameroon, the average incidence was 63% and leaf attack index was 1 corresponding to 20 %. In the bimodal rainforest zone (central Cameroon region), the average incidence was 60 % for a leaf attack rate was 37.11%. The expected results highlight a relatively worrying situation. Principal Component Analysis (PCA) confirms the convergence of tolerance towards the mosaic and grouped the different varieties into more or less homogeneous groups according to the morphological and epidemiological cassava descriptors. The results of the present work show that the introduction of cassava local varieties tolerant to mosaic disease in middling could be an alternative for the control of the cassava mosaic disease.

Keywords: African mosaic, variety, prevalence, characterization


How to Cite

Alain , Heu, Mboussi Serge Bertrand, Kone Nsangou Nourou Abdou, Dida Lontsi Landry Sylvere, Ngoh Dooh Jules Patrice, and Ambang Zachee. 2024. “Prevalence of African Mosaic and Morphological Characterization of Cassava (Manihot Esculenta Cranz) Varieties in Two Agroecological Zones of Cameroon”. Journal of Experimental Agriculture International 46 (6):222-49. https://doi.org/10.9734/jeai/2024/v46i62474.