In Cameroon, oil palm ( Elaeis guineensis Jacq.) is of economic importance. However, it is affected by vascular wilt presumed to be caused by Fusarium oxysporum f. sp. elaeidis (FOE). Accurate species identification requires molecular-based comparisons. The aim of this work was to molecularly identify Fusarium species associated with diseased oil palms and to determine the pathogenicity of selected isolates. Fungal samples of diseased palms were collected from the canopies and the soil of five oil palm estates of the Cameroon Development Corporation and characterized by sequencing and comparing the translation elongation factor 1a gene. The results revealed the presence of FOE from approximately 80% of the isolates. Cameroonian isolate within FOE clade 1 exhibited the greatest variability grouping with isolates from Suriname, Brazil and Democratic Republic of Congo. Other isolates found in FOE clade 2 formed a unique group which was comprised solely of isolates originating from Cameroon. Twenty-two isolates were chosen for pathogenicity tests. After a short time, 14 isolates were found to be pathogenic to oil palm seedlings. This study revealed the pathogenicity of FOE isolates from Cameroon and demonstrated that FOE in Africa is more diverse than previously reported, including a lineage not previously observed outside of Cameroon. Comparisons between all isolates will ultimately aid to devise appropriate control mechanisms and better pathogen detection methods.

The objectives of developing oil palm plantations should feasible economically and without causing massive erosion. This research proposes soil and water conservation strategies that are ideal and optimal for oil palm cultivation depending on land capability class. The conservation test for plants was performed according to land capability classes on a plot measuring 22 m × 4 m. Runoff and erosion rates were measured using Multislot Divisor Method. Nutrient leaching was analysed based on the content of C-organic (Ctot) (Walkley–Black method), total nitrogen (Ntot) (Kjeldahl method), P-available (Bray-1 method) and K2O (extraction with 1N NH4OAc at pH 7.0). From the results, land capability class III, cover crops (soybean) + manure (P3) treatment effectively reduced runoff and soil erosion (22.63 m3∙ha–1∙y–1 and 13.04 Mg∙ha–1∙y–1), as well as nutrient leaching, compared to other treatments. Furthermore, sediment trap + cover crop + manure (P3) controlled runoff, erosion and nutrient leaching on land capability class IV, producing the lowest runoff (129.40 m3∙ha–1∙y–1), soil erosion (11.39 Mg∙ha–1∙y–1), C-organic (1.3%), and P (1.95 mg kg–1). Soil conservation treatment significantly reduced erosion and runoff (p < 0.05) on land capability class VI. The bench terrace + cover plants + manure treatment-controlled runoff, erosion, and soil nutrient leaching.

Escalating quantity of industrial by-products generated, including oil palm shell (OPS) and palm oil fuel ash (POFA ) of the palm oil industries, has been a concern to many analysts. They are mostly disposed off as wastes that would heavily impact the environment quality. Therefore, this paper aimed to investigate the possibility of consuming these wastes by using OPS and POFA as replacement materials for fine aggregates in the concrete mixture. The mixtures were prepared by integrating unground palm oil fuel ash of 0%, 10%, and 20% (by weight of sand) to produce lightweight concrete. The experiments observed the mechanical performance of these specimens for 180 curing days. The results show the enhancement of concrete strength relative to the control mixture by using 10% of ash. This is owing to void filling mechanism and product of pozzolanic reaction due to the fine particles of the ash.