Potato (Solanum tuberosum L) production in the Far North Region of Cameroon is faced with scarcity or inequality of rains and with diseases that affect yields. To improve the production a study was conducted in the production area of Mogode subdivision with the objective of identifying potato diseases and pathogens agents. The experimental design was in complete randomized blocks. The plant material used was a local variety of potato (Dosa). Diseases and pathogens have been identified on a base of symptoms and morphological characteristics. The incidence, severity and rainfall were assessed. Yield, number of stems and diameter of the tubers were evaluated. The diseases identified are fungal (late blight, Alternaria or early blight and Fusarium wilt), viral (Virosis M, Rust stain and Potato leaf roll (PLR) and bacterial (Bacterial wilt and Common scab). Conidia of Phytophthora infestans, and Alternaria spp. were found.Whatever the site and disease, the incidence has remained below 25%. Late blight was more present in the Gouria site, Alternaria and virosis M more present in the Mouvou site. The yield was roughly the same at the two sites, around 3 t/ha. The highest number of stems was obtained at Gouria, 18 ± 0.75. The potato is attacked by several diseases. The results of this study represent an important baseline data for the implementation of integrated disease management in Cameroon.Keywords: Solanum tuberosum, diseases, pathogens, incidence, severity, yield.

Aims: The aim of this work was to evaluate effect of Mancozeb 80 WP against Colletotrichum gloeosporioides, the agent responsible of anthracnose of cashew tree (Anacardium occidentale  L.). Study Design: The experimental design was in completely randomized blocks with three replications. Place and Duration of Study: in vitro and in vivo experiments were performed in Laboratory of  Department of Biological Sciences, University of Maroua during six months. Field trial was carried out in Kelo, Chad during three months. Methodology: Isolates were obtained from diseased organs (leaves and fruits) from Kélo in Chad and Maroua in Cameroon. The concentrations used in the laboratory were C1 (5 mg/ml), C2 (0.5 mg/ml), C3 (0.05 mg/ml), C4 (0.005 mg/ml), C5 (0.0 mg/ml). Radial growth, sporulation, conidial germination and pathogenicity were used to characterize and evaluate the effect of Mancozeb on the isolates in vitro. The preventive test was performed on three-month-old plants previously treated with Mancozeb. The concentration of 5 g/l was applied to the field and the incidence and severity were used to calculate the AUIPC (Area Under Disease Incidence Progress Curve) and AUSiPC (Area Under Disease Severity Index Progress Curve) curves. Results: Mancozeb reduced radial growth of all isolates at concentrations C1 (5 mg/ml), C2 (0.5 mg/ml) and C3 (0.05 mg/ml). The percentages of inhibition ranged from 50 to 100%. Mancozeb 80 WP completely (100%) inhibited the germination of C. gloeosporioides conidia in vitro. Mancozeb has protected cashew plants in vivo at the concentration C1 (5 mg/ml). AUIPC and AUSiPC were higher on control plants and lower on Mancozeb-treated plants. Conclusion: Mancozeb 80 WP may be associated in integrated pest management strategy against anthracnose.

Introduction: Potato production in the Far North Region, Cameroon is hampered by a wide range of fungi of the genus Fusarium. Aims: The aim of this work was to isolate and conduct physiological characterization of Fusarium spp. isolates responsible for potato Fusarium disease in the Far North Region, Cameroon. Methodology: Isolates were obtained from diseased organs (leaves) from fifteen villages in the district of Mogodé, Mokolo and Koza, Far North Cameroon. The species responsible for fusariosis were identified using several identification Keys on a base of symptoms and morphological spores characteristics (macroconidia, microconidia and chlamydospores). Fusarium incidence and rainfall were assessed. Radial growth, sporulation and pathogenicity of the isolates were use to evaluated the parameters of physiological characterization.  Results: The overall average incidence of Fusarium head blight in the Far North Region, Cameroon is 29.36%. Furthermore, out of the 20 isolates obtained, six Fusarium species (Fusarium oxysporium, F. solani, F. equiseti, F. avenacearum, F. colmorum and F. sambicum) were identified. The highest growth rate (8.1 cm), the highest spore production (8 × 105) and the highest severity index (3%) were respectively obtained with the isolates FUROM 2 and FUTEK 3, FUMOG 1, FUMOG 2, FUROM 1 and FURAF from Mogodé District on PCA medium. Conclusion: Potato production in the Far North Region, Cameroon is confronted by various Fusarium species which have physiological characteristics that vary according to the area of origin of the isolates and the growing media.

Background and Objective:The dieback of mango (Mangifera indica) has become an increasing threat to mango production in Tchad and Cameroon. The present study was conducted to characterize and identify pathogens associated with the mango quick decline tree for the first time in both countries. Materials and Methods: Investigations were carried out through field observations of the symptoms. A simple block experimental design was adopted and the scale was used to assess the incidence, severity and prevalence at the two sites during the dry and rainy seasons. Pathogens associated were isolated using a Potato Dextrose Agar (PDA) medium. The control strategy was evaluated. Results: During the survey, symptoms of this disease were wilting of leaves and branches which gradually progress into dieback, gummosis, rotting of the stem and vascular discolouration. Six fungi, Lasiodiplodia theobromae, Colletotrichum sp., Aspergillus niger and Botrytis cinerea were present in the dry season and the two sites, Curvularia sp. and Schizosaccharomyces pombe occurring in the rainy season only in Cameroon were isolated. The highest incidence and severity rates were obtained during the rainy season, 43.94 and 14.03%, respectively. Kassai variety (25%) was the most susceptible to dieback. The percentage of tree regeneration from the cutting method depends on the attack percentage of the tree. Conclusion: This study suggested that several fungi are associated with this disease in Cameroon and Chad. Molecular analysis and pathogenicity are necessary to upset the control strategy (cutting method) which is efficient when the attack tree is under 50%.