Journal of the Cameroon Academy of Sciences

Alternative control methods for Fall army worm in some agroecologies in Cameroon

Kamtchoum Stephane Martial — 2024-08-27

Maize cultivation in Cameroon faces threats from the fall armyworm (Spodoptera frugiperda), significantly reducing crop yields. This study explores eco-friendly, safe, and accessible pest control methods. Trials were conducted in Garoua (zone I), Foumbot (zone III), and Ntui (zone V) using six treatments: Control, Emamectin (RAPAX), Bacillus thuringiensis, Soap, A. indica oil (neem), and Bacillus thuringiensis + Emamectin. All treatments showed insecticidal effects compared to the control, with Emamectin, Bacillus thuringiensis + Emamectin, A. indica oil, and Bacillus thuringiensis being most effective. High incidence rates were found in zones I and III (55.82% and 44.17%) versus zone V (34.72%). Significant positive correlations existed between attack severity and incidence (r=0.801), larval numbers with incidence (r=0.639) and severity (r=0.420), while grain yield had significant negative correlations with incidence (r= -0.736), severity (r= -0.931), and larval numbers (r= -0.690). Yield analysis showed significant effects (P<0.05) from all treatments compared to control. Emamectin yielded 2950kg/ha, followed by Emamectin + Bacillus thuringiensis (2783kg/ha). Control treatments yielded 1100kg, while soap, A. indica, and Bacillus thuringiensis yielded 2257kg/ha, 2607kg/ha, and 2750kg/ha respectively. No significant zone effect was noted. The study emphasizes balancing economic and efficacy factors in pest control method selection, with neem oil, emamectin benzoate, and RAPAX suitable for various pest pressures and environmental conditions.

Evaluation of antifungal activity of lactic acid bacteria from locally sourced yoghurts on isolates of Candida Albicans from cases of vaginitis

Okunye Olufemi Lionel — 2024-08-27

This study assessed antifungal activity of lactic acid bacteria from locally made yoghurts on isolates of candida albicans from cases of vaginitis. Locally sourced yoghurt samples were cultured on MRS agar and incubated anaerobically at optimum temperature for the isolation of Lactic Acid Bacteria. The pH and total viable counts parameters of the isolates from the samples were determined. Isolates of Candida albicans from cases of vaginitis collected were biochemically confirmed after SDA plated. The isolates were exposed to antifungal agents with varied concentrations and thereafter, challenged with Lactic Acid Bacteria laden yoghurt samples prepared in varied concentration on MRS agar overlayered with SDA. Plasmid DNA of the LAB isolates were determined. The isolates of Candida albicans exhibited 100% resistance to conventional antifungal agents exposed with the exception of Candida albicans 1 that were susceptible to all the antifungal agents while Candida albicans 4 was susceptible to amphotericin B, fluconazole, and nystatin. Three(3) of the four (4) isolates of Candida albicans challenged with Habib (LABHAY) and Tunik(LAB TY ) yoghurt were 100% susceptible the LAB laden yoghurt samples while Candida albicans isolates 3 (Ca3) were (100%) resistant to LABHAY and LAB TY. Of the the four(4) isolates of Candida albicans were(100%) susceptible to Cedaar (LABCY) and Fan milk(LABFM) yoghurt and while Candida albicans isolates number 3 (Ca3) exhibited resistance to LABCY and LABFM. Lactic Acid Bacteria in this study, exhibited remarkable antifungal activity on Candida albicans isolates from cases of vaginitis. This property could be exploited as a bio-protective and therapeutic option, for cases of Candida albicans and fungi with related features.

The effect of two fertilizer types on growth, yield, gluten content of two Cameroon wheat landraces

E. Tatah Lendzemo — 2024-08-27

Wheat (Triticum aestivum) is one of the most important cereals in the world, providing 20% of calories in the daily diets of the world. Wheat is highly consumed in Cameroon directly or processed into bread and biscuits. However, the need to increase quality wheat production in Cameroon is emphasized especially in the wake of the geopolitical crisis between Ukraine and Russia. This study was designed to ascertain the impact of two nitrogen sources (urea and Ammonium sulphate) at different doses (0g, 2g, 4g and 6g) per plant on growth, yield and gluten content of two Cameroon landraces of wheat (Boyo and Adamawa). In April 2022, a split plot experiment with landrace as main plots and fertilizer doses as subplots was established in the research field of the Regional College of Agriculture Bambili, North West Region of Cameroon. Plant height did not vary across fertilizer doses but Boyo was significantly taller than Adamawa (P < 0.05). The number of leaves and the number of tillers progressively increased with fertilizer doses. The number of spikes increased with increased fertilizer doses and the values for Boyo were higher than those for Adamawa for corresponding doses. Interaction effects of variety x dose was significant (F = 7.162, df = 3, 40, P = 0.001) on the number of grains with Boyo and Adamawa landraces producing 331 and 320 grains per plant, respectively from 6g of urea. Boyo and Adamawa produced 337 and 449, from 6g and 4g of ammonium sulphate respectively. Grain weight and gluten content increased with increase doses of fertilizers with the highest grain weight and gluten content from Adamawa landrace at 6g of ammonium sulphate per plant. The Adamawa landrace at 6g per plant of ammonium sulphate is recommended for increased yield and gluten. Other ramifications are discussed.

Identification of Spodoptera frugiperda (Lepidoptera: Noctuidae), effects of farmer’s management tools and Neem Oil Doses on fall armyworms in the Mangoun locality, Foumbot Subdivision, Cameroon

E.S Djomaha — 2024-08-27

The abusive use of chemical insecticides poses a threat to humans. The use of botanical insecticides in combating crop pests is now an alternative. This study aimed to evaluate the damage caused by fall armyworms (FAW) in relation to planting dates, maize varieties, insecticides in farmers’ fields and the effect of neem oil doses for their control in the Noun department. Neem oil at three doses (3, 5, 7 L/ ha) was compared with a synthetic insecticide, Emamectin benzoate. The experiment was conducted using a randomized complete block design with five treatments replicated five times. Total number of leaves per plant, and number of leaves, whorls, and stems attacked were recorded. Results indicated an average attack rate of 20.29 ± 1.27%. However, leaf infestation rates varied among farmers depending on the variety used, planting date, and insecticide application. The 7 L/ha neem dose had the greatest impact on FAW, followed by the moderate dose (5 L/ha) and then the lowest dose (3 L/ha). Leaf infestation rates at the end of the experiment were 21.69 ± 0.89%, 16.66 ± 1.60%, and 9.89 ± 1.30% for neem3, neem5, and neem7 respectively. Neem7 showed effectiveness comparable to that of synthetic insecticide. Therefore, neem at 7 L/ha presents an alternative solution for combating FAW.

Antibacterial activity of zinc oxide nanoparticles and gentamicin on Xanthomonas campesiris on infested tomato from Bodija market, Ibadan Nigeria - a quantitative comparative study

Olufemi Lionel Okunye — 2024-08-27

Les nanoparticules d’oxyde de zinc sont apparues comme un nouvel outil en agronomie et en protection des cultures grâce à leur efficacité dans la lutte contre les pathogènes bactériens des plantes résistants aux agents antibactériens conventionnels. Les nanoparticules d’oxyde de zinc et la gentamicine ont été testées quantitativement contre Xanthomonas campesiris vesicatoria, l’agent pathogène responsable des taches infectieuses avant et après la récolte de la tomate. Exactement 0,1 ml de la suspension de tomate broyée a été étalé de manière aseptique sur un milieu gélosé au saccharose et a été incubé à une température optimale pendant 24 à 48 heures. Des tests de pathogénicité des isolats ont été réalisés sur des tomates non infectées afin d’authentifier les isolats infectieux obtenus. Des extraits aqueux et éthanoliques de nanoparticules d’oxyde de zinc et des antibiotiques gentamicine ont été testés sur les isolats de Xanthomonas campesiris vesicatoria confirmés, par technique de diffusion en coupe d’agar. Extrait aqueux et éthanolique de nanoparticules d’oxyde de zinc et d’antibiotiques gentamicine préparés en concentrations variées ; 5 µg/mL, 2,5 µg/mL, 1,25 µg/mL dans différentes dilutions doubles ont été testés sur Xanthomonas campesiris vesicatoria obtenu et ont présenté une activité antibactérienne compétitive significative. L’extrait éthanolique a montré une activité antibactérienne plus forte que l’extrait aqueux. La gentamicine, un antibiotique à large spectre, exerce une activité antibactérienne compétitive à chaque dilution. La croissance de Xanthomonas campestris pv.vesicatoria, l’agent étiologique de la tache infectieuse chez la tomate, a été remarquablement supprimée par les nanoparticules d’oxyde de zinc, comme cela a également été observé dans la gentamicine.

Hydrochemistry of surface and groundwater along the Coast of Kribi and its environs

Melisa Bijingsi — 2024-08-27

Ground and surface water are the major sources of water supply to the population of Kribi and other communities around this area. A hydrochemical investigation was carried out on the water sources in the area, aimed at identifying the various processes that control the water chemistry, and to assess its quality for domestic purposes. Fifty-six water samples were collected from boreholes, springs, open wells, rivers, rain and tap within the study area during the months of October 2021 and March 2022. Physicochemical characteristics such as pH, electrical conductivity (EC), total dissolved solid (TDS), temperature and major ions were analysed using standard methods. The result indicated that, the pH ranged from 6.3 to 7.0 in the rainy season and 6.2 to 6.5 in the dry season indicating that water in this area is slightly acidic to neutral. EC values ranged from 23.0 to 989µS/cm and 50.9 to 356µS/cm in the rainy and dry seasons respectively and the high EC values in the rainy season indicates high mineralization of the water sources. The TDS ranged from 34.10 to 662.63ppm and 15.41 to 238.52ppm in the rainy and dry seasons respectively. The relative abundance of major ions was K⁺ > Na⁺ > Ca²⁺ > Mg²⁺> NH₄ ⁺ for cations and NO₃ " > HCO₃ “ > Cl” > SO₄²" for anions. The main water types were: Ca+Mg-SO₄⁺Cl, Na+K-SO₄+ Cl, Na+K-HCO₃ and Ca⁺Mg^- HCO₃ for both seasons. The processes that influence the water chemistry were rock-weathering, mineral dissolution, ion exchange and atmospheric precipitation. The chemical constituents were low and within the international recommended guidelines for drinking water except for high concentrations of NO₃ ^- (284 mg/l) and K+ (75.8 mg/l). Water quality index calculated using data for chemical parameters indicated that 96.8% of the water sources was of good to excellent for domestic purposes while 3.2% was of poor water quality. Based on the above parameters, water sources in this area are suitable for domestic purposes.

Physical vulnerability assessment and household preparedness of Buea Municipality to seismic hazards from Mount Cameroon Eruptions: A cause for concern

Nchini Livinus Wayih — 2024-08-27

Earthquakes associated with volcanic eruptions from Mount Cameroon can impact society and building infrastructures. This study therefore aimed to assess the following: i) the geological features (rock/soil types) and its characteristics in selected localities within Buea municipality; ii) past-eruption/earthquake impact assessment on buildings; iii) physical vulnerability of buildings infrastructure and iv) household preparedness to earthquake hazards. The study utilized a mixed-method approach, combining quantitative and qualitative techniques. Geological characteristics was assessed through site visits across the selected ten localities by physical observation and rock sample collection. Past-eruptions (1959, 1982, 1999, 2000) impacts assessment on buildings and household preparedness to earthquakes were evaluated using structured questionnaires. Building vulnerability was assessed using the ENSURE and the Building Vulnerability Index (BVI) methodology on the following parameters: building state, building materials, house position (single, row, clustered), house age, proximity to volcano and the surrounding soils/rocks. Findings revealed the rock types are predominantly made up of basaltic rocks/ lava, pyroclastic deposits, tuff, lahar deposits and brownish to black loamy soils. Earthquake impact on buildings from the 4 eruptions revealed that localities around the epicenter were the most affected. Physical vulnerability assessment revealed that 35 % of the vulnerable buildings were < 5 years old and were residential buildings. Quantitative analysis of building vulnerability indicated moderate vulnerability to seismic hazards in 50 % of the assessed localities. For household preparedness to volcanic earthquakes: 32.0 % of households had first aid kits and 73.1 % had identified safe evacuation locations. The study revealed that the presence of tuff, soft and loose unconsolidated soils; the position and state of buildings; and the absence of evacuation plans significantly contributed to seismic vulnerability in Buea municipality.

Sustainability and inclusion from African perspectives

Therese Mungah Shalo Tchombe — 2024-08-27

Sustainability entails a change in the exploitation of resources while maintaining essential ecological processes and life support systems, preserving genetic diversity, and ensuring the utilisation of species and ecosystems. Effective realisation of sustainability requires the implementation of inclusive practices, whereby diversity is embraced from the educational, economic, social, cultural, and psychological dimensions of human life and climate change. Commenting on the African perspective, the need to search for alternative solutions to Africa’s development challenges calls for a critical examination of what sustainability and inclusion mean for Africans and how these can impact their lives in the 21st century. Sustainability and inclusion from African perspectives, therefore, raise concerns about the cultural, socioeconomic, political, health, spiritual, environmental, and socially responsible processes, underpinned by Africentric humanistic philosophies of communalism and socialism. The discussions of this paper posit a paradigm shift from Eurocentric scientific and pedagogical principles. In this light, the paper critically situates the significance of Ujamaa and Ubuntu, African philosophies to illustrate that sustainability and inclusion, are exemplified by harmonious relationship between the human being and nature. Nonetheless the changing context of Africa poses some new challenges for sustainability and inclusion within African cultures. Development issues ought to be people-driven, inclusively focusing on African values, guided also by relevant orientations from Africa’s Agenda 2063 of “an integrated, prosperous and peaceful Africa, driven by its citizens and representing a dynamic force in the international arena”.