1. Faculty of Sciences, University of Bangui

2. Laboratoire de biodiversité végétale et fongique, République Centrafricaine

3. Laboratory of the Ecole Normale Supérieure

4. Laboratory of the Ecole Normale Supérieure

5. Laboratory of Analysis, Architecture and Reactivity of Natural Substances (LAARSN)

Corresponding author: madiapevostephane@gmail. com

Abstract

Between August and October 2024, a study was conducted on the exploitation of Marantaceae leaves in the Ombela M’Poko forest area up to marketing in the Bangui markets. A total of 𝟷06 randomly selected actors constituted the sample. It emerged that 2 species of Marantaceae are harvested and sold in the Bangui markets. These are mainly: Megaphrynium macrostachyum and Sarcophrynium brachystachyum. These two leaves are used for various purposes. The surveys revealed that Marantaceae leaves are present in the markets surveyed, sold fresh in modest quantities. The wholesale prices of Marantaceae leaves cost 3,000 CFA francs in the villages surveyed; in Bangui the wholesale prices are 7,500 CFA francs and 100 CFA francs in retail. Two types of commercial circuits have however been identified: the short circuit and the long circuit. The main actors are the pickers, the intermediaries and the consumers. Concerning the profit margins, it is the wholesaler who generates the most important margin estimated at 𝟷 638 000 F CFA (3 months per year). Given the economic potential of these resources, it would be essential to valorize them.

Keywords: Analysis, marantaceae sector, Central African Republic.

Résumé

 Entre août et octobre 2024, une étude a été menée sur l’exploitation des feuilles de Marantacées dans la zone forestière d’Ombela M’Poko jusqu’à la commercialisation sur les marchés de Bangui. Un total de 106 acteurs sélectionnés au hasard a constitué l’échantillon. Il ressort que 2 espèces de Marantacées sont récoltées et vendues sur les marchés de Bangui. Il s’agit principalement de : Megaphrynium macrostachyum et Sarcophrynium brachystachyum. Ces deux feuilles sont utilisées à diverses fins. Les enquêtes ont révélé que les feuilles de Marantacées sont présentes sur les marchés étudiés, vendues fraîches en quantités modestes. Les prix de gros des feuilles de Marantacées s’élèvent à 3 000 francs CFA dans les villages étudiés ; à Bangui, les prix de gros sont de 7 500 francs CFA et 100 francs CFA au détail. Deux types de circuits commerciaux ont toutefois été identifiés : le circuit court et le circuit long. Les principaux acteurs sont les cueilleurs, les intermédiaires et les consommateurs. En ce qui concerne les marges bénéficiaires, c’est le grossiste qui génère la marge la plus importante estimé à 1 638 000 F CFA (3 mois par an). Étant donné le potentiel économique de ces ressources, il serait essentiel de les valoriser.

 Mots-clés : Analyse, secteur des Marantacées, République centrafricaine.

1. Faculty of Sciences, University of Bangui

2. Laboratoire de biodiversité végétale et fongique, République Centrafricaine

3. Laboratory of the Ecole Normale Supérieure

4. Laboratory of the Ecole Normale Supérieure

5. Laboratory of Analysis, Architecture and Reactivity of Natural Substances (LAARSN)

Corresponding author: worowoungax@yahoo.fr; worowoungax@gmail.com

                                 Figure 1. Talinum triangulare (a), Xylopia aethiopica (b)

ABSTRACT

Wild food plants are natural resources that are, essential to humans for their nutritional and health needs and also for their income as well as for the conservation of biological diversity. This study aims to inventory plants with nutritional and therapeutic potential in the Commune of Lessè (RCA), with the aim of promoting these biological resources. From April to July 2024, field missions, based on the use of individual interviews using a semi-structured questionnaire, were carried out in four villages, chosen on the basis of cultural importance and the abundance of natural resources. These are mainly Karawa, Gbabili, Yéma – kabo and Mbanza. In each village, 15 people were interviewed, for a total of 60 individuals interviewed. 81 plant species of wild origin belonging to 62 genera and 40 different families were identified. The population surveyed consumes them to diversify their diet. Which is also very beneficial for the supply of essential nutrients (proteins, fats and sugars), vitamins and antioxidants. The botanical family with a high diversity in specific terms is that of Euphorbiaceae with 5 species respectively. In the villages surveyed, 76 species of wild food plants or 93.82% are better known and more consumed in Karawa than in other localities. Concerning the organs consumed, fruits (57, 28%) and leaves (35.92%) are the most requested organs in food. The results also showed that 40 species or 49.32% which is almost half of the species identified are the subject of flourishing marketing in rural markets. Their selling price varies between 0.04 to 0.81 USD with a sum of 7.74 USD. Rural women are the real actors. The harvest and sale of these biological resources not only contribute to strengthening food security but also contribute to the household economy in the study area. Apart from nutritional interest, 31 species of wild food plants are used in traditional medicine treating 43 diseases. Given the dual nutritional and therapeutic interest of these biological resources, it would be essential to enhance and safeguard them in order to combat food insecurity and reduce poverty in rural areas. Similarly, such an approach could allow the cultivation/domestication/conservation of this food and medical heritage.

Keywords: Ethnobotany, wild food plants, medicinal, conservation, Central African Republic.

RÉSUMÉ

Les plantes alimentaires sauvages sont des ressources naturelles essentielles pour les humains, tant pour leurs besoins nutritionnels et de santé que pour leurs revenus et pour la conservation de la biodiversité. Cette étude vise à inventorier les plantes ayant un potentiel nutritionnel et thérapeutique dans la commune de Lessè (RCA), dans le but de promouvoir ces ressources biologiques. D’avril à juillet 2024, des missions sur le terrain, basées sur l’utilisation d’entretiens individuels avec un questionnaire semi-structuré, ont été réalisées dans quatre villages choisis en fonction de leur importance culturelle et de l’abondance des ressources naturelles. Il s’agit principalement de Karawa, Gbabili, Yéma-kabo et Mbanza. Dans chaque village, 15 personnes ont été interrogées, soit un total de 60 individus. 81 espèces de plantes d’origine sauvage appartenant à 62 genres et 40 familles différentes ont été identifiées. La population interrogée les consomme pour diversifier son alimentation, ce qui est également très bénéfique pour l’apport en nutriments essentiels(protéines, graisses et sucres), vitamines et antioxydants. La famille botanique présentant une grande diversité en termes spécifiques est celle des Euphorbiacées avec 5 espèces respectivement. Dans les villages enquêtés, 76 espèces de plantes alimentaires sauvages, soit 93,82 %, sont mieux connues et plus consommées à Karawa qu’ailleurs. En ce qui concerne les organes consommés, les fruits (57,28 %) et les feuilles (35,92 %) sont les organes les plus demandés en alimentation. Les résultats ont également montré que 40 espèces, soit 49,32 %, ce qui représente presque la moitié des espèces identifiées, font l’objet d’un commerce florissant sur les marchés ruraux. Leur prix de vente varie entre 0,04 et 0,81 USD avec un total de 7,74 USD. Les femmes rurales sont les véritables actrices. La récolte et la vente de ces ressources biologiques contribuent non seulement à renforcer la sécurité alimentaire, mais aussi à l’économie des ménages dans la zone étudiée. Outre l’intérêt nutritionnel, 31 espèces de plantes alimentaires sauvages sont utilisées en médecine traditionnelle pour traiter 43 maladiesCompte tenu de l’intérêt nutritionnel et thérapeutique de ces ressources biologiques, il serait essentiel de les valoriser et de les protéger afin de lutter contre l’insécurité alimentaire et de réduire la pauvreté dans les zones rurales. De même, une telle approche pourrait permettre la culture/la domestication/la conservation de ce patrimoine alimentaire et médical.

Mots-clés : ethnobotanique, plantes alimentaires sauvages, médicinales, conservation, République centrafricaine.

^[1]  Ecole Nationale Supérieure des Travaux Publics, BP 510, Département de Génie de l’Environnement, Yaoundé (Cameroun)

^[2]  Université de Yaoundé I, BP 812, Faculté des Sciences, Département d’Informatique, Yaoundé (Cameroun)

          * Correspondence:  asiatud@yahoo.com et  sergeebele@gmail.com                                                                                      

             ORCID iD: 0000-0002-2658-3684

RESUME

L’utilisation intensive des pesticides en agriculture constitue l’une des principales sources de contamination des écosystèmes aquatiques, en particulier dans les zones rurales où les pratiques agricoles sont peu encadrées. Le présent travail avait pour objectif d’évaluer la toxicité aiguë du pesticide SUPER CHAMPS 36 WP sur les alevins de Oreochromis niloticus et d’estimer le risque environnemental associé à son utilisation en milieu aquatique. L’étude a été réalisée à l’aide d’un dispositif expérimental en mésocosmes au laboratoire de Génie de l’Environnement, exposant les alevins à différentes concentrations du pesticide pendant une durée maximale de 96 heures. Les résultats obtenus ont mis en évidence une toxicité aiguë élevée, caractérisée par une mortalité rapide et dose-dépendante, avec une CL50 atteinte à de faible concentration. L’évaluation du risque environnemental, basée sur le calcul du quotient de risque (RQ = 5,45), révèle que les concentrations environnementales prédites dépassent largement les seuils de sécurité établis pour les organismes aquatiques.  L’analyse approfondie du risque environnemental montre que l’utilisation du SUPER CHAMPS 36 WP représente un danger significatif pour les écosystèmes aquatiques, en particulier pour les stades précoces de développement des poissons. Les résultats suggèrent également une possible sous-estimation du risque réel, notamment en raison des effets chroniques, des expositions répétées et des conditions environnementales spécifiques aux zones tropicales. Ce travail souligne ainsi la nécessité de renforcer les stratégies de gestion des pesticides afin de préserver la biodiversité aquatique et la sécurité des écosystèmes.

Mots-clés : Pesticide, SUPER CHAMPS, Ecotoxicité, Oreochromis niloticus, Mésocosme, Concentration létale 50, Risque écologique.

ABSTRACT

The intensive use of pesticides in agriculture is one of the main sources of contamination in aquatic ecosystems, particularly in rural areas where agricultural practices are poorly regulated. The aim of this study was to evaluate the acute toxicity of the pesticide SUPER CHAMPS 36 WP on the fry of Oreochromis niloticus and estimate the environmental risk associated with its use in aquatic environments. The study was conducted using an experimental mesocosm setup in the Environmental Engineering Laboratory, exposing the fry to various pesticide concentrations for a maximum duration of 96 hours. The results showed high acute toxicity, characterized by rapid, dose-dependent mortality, with a 50% lethal concentration (LC50) reached at low concentrations. The environmental risk assessment, based on the risk quotient calculation (RQ = 5.45), revealed that predicted environmental concentrations greatly exceed the established safety thresholds for aquatic organisms. A detailed analysis of the environmental risk indicates that the use of SUPER CHAMPS 36 WP poses a significant threat to aquatic ecosystems, especially for the early developmental stages of fish. The results also suggest a potential underestimation of the actual risk, particularly due to chronic effects, repeated exposures, and environmental conditions specific to tropical regions. This study highlights the need to strengthen pesticide management strategies to preserve aquatic biodiversity and ecosystem safety.Keywords: Pesticide, SUPER CHAMPS, Ecotoxicity, Oreochromis niloticus, Mesocosm, 50% Lethal Concentration, Ecological Risk

^[1]  Ecole Nationale Supérieure des Travaux Publics, BP 510, Département de Génie de l’Environnement, Yaoundé (Cameroun)

^[2] Université de Yaoundé I, BP 812, Faculté des Sciences, Département d’ Informatique, Yaoundé (Cameroun)

          * Correspondence: asiatud@yahoo.com  et sergeebele@gmail.com                                                                                 

             ORCID iD: 0000-0002-2658-3684

RESUME

Les pesticides sont des produits destinés à lutter contre les parasites animaux, végétaux et les adventistes indésirables des cultures, des plantes, des voiries et espaces de loisirs (insecticides, herbicides, fongicides). Ces produits contiennent des substances chimiques toxiques susceptibles de nuire à la santé environnementale et biologique.  Cette étude évalue les effets écotoxicologiques du pesticide BENJI 250 SP (l’Acétamipride 250 g/kg WP) sur les alevins de tilapia (Oreochromis niloticus) en conditions expérimentales. Six mésocosmes ont été utilisés, dont un témoin (M1) et cinq autres avec des concentrations croissantes de pesticide (0,5, 1, 2, 4 et 8  mg/L dans M2 à M6 respectivement). L’expérimentation, conduite du 03 au 16 Janvier 2026, a consisté à observer la mortalité des poissons pendant 96 heures d’exposition. Les résultats montrent une relation dose-réponse significative, avec une mortalité augmentant proportionnellement à la concentration du pesticide. La CL50-96h de l’         Acétamipride a été estimée 1,5 mg/L. L’analyse du risque écologique, basée sur le rapport PEC/PNEC avec un facteur de sécurité de 10, suggère un risque environnemental de faible à modère pour les organismes aquatiques aux concentrations testées. Cette étude confirme la toxicité aiguë du l’Acétamipride pour les poissons d’eau douce et souligne la nécessité de mesures de mitigation lors de l’utilisation de ce pesticide en zones aquatiques. Les effets de la toxicité aiguë de Acétamipride sur les alevines de poissons de tilapia constitue un risque écologique non négligeable. Et le transfert de ce toxique bioaccumulable à travers la chaine alimentaire constitue un risque majeur pour la population environnante.

Mots-clés : BENJI 250 SP, Acétamipride, Tilapia, Toxicité aiguë, Condition expérimentale, CL50, Risque Environnemental

ABSTRACT

Pesticides are products used to combat animal pests, weeds, and undesirable plants in crops, gardens, roadsides, and recreational areas (insecticides, herbicides, fungicides). These products contain toxic chemical substances that can harm environmental and biological health. This study evaluates the ecotoxicological effects of the pesticide BENJI 250 SP (Acetamiprid 250 g/kg WP) on tilapia fry (Oreochromis niloticus) under experimental conditions. Six mesocosms were used, including one control (M1) and five with increasing pesticide concentrations (0.5, 1, 2, 4, and 8 mg/L in M2 to M6, respectively). The experiment, conducted from January 3 to 16, 2026, involved observing fish mortality over 96 hours of exposure. The results show a significant dose-response relationship, with mortality increasing proportionally to the pesticide concentration. The 96-hour LC50 of Acetamiprid was estimated at 1.5 mg/L. The ecological risk analysis, based on the PEC/PNEC ratio with a safety factor of 10, suggests a low to moderate environmental risk based on the scenarios for aquatic organisms at the tested concentrations. This study confirms the acute toxicity of Acetamiprid for freshwater fish and highlights the need for mitigation measures when using this pesticide in aquatic areas. The acute toxicity effects of Acetamiprid on tilapia fry pose a significant ecological risk. Additionally, the bioaccumulative transfer of this toxic substance through the food chain presents a major risk to the surrounding population.

Keywords: BENJI 250 SP, Acetamiprid, Tilapia, Acute Toxicity, Experimental Conditions, LC50, Environmental

¹ Higher Institution Centre of Excellent (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

² Department of Animal Sciences, University of Buea, Republic of Cameroon

Corresponding author: norazman@umt.edu.my

Abstract

This study investigated the growth performance, survival, and water quality variations in Gladiator swimming crab (Callinectes sp.) aquaculture across three different systems: Recirculating Aquaculture System (RAS) with ultraviolet filter (System A), RAS without ultraviolet filter (System B), and a flow-through system (System C). Initial growth performance assessments showed a uniform average initial weight of 1.63 g across all systems. After six weeks, significant differences in final weight, carapace length, and width were observed among the systems (p<0.05). Crabs in System C exhibited the highest growth performance, achieving a final average weight of 16.45 ± 0.58 g, a Specific Growth Rate (SGR) of 35.50 ± 1.0%, and carapace measurements of 31.45 ± 1.34 mm in length and 52.40 ± 0.93 mm in width. Statistical analyses revealed strong correlations between water quality parameters and growth performance metrics, with ammonia nitrogen concentrations showing a significant relationship with specific growth rate and weight gain. These findings highlight the importance of optimized water quality management and appropriate feeding strategies in enhancing the growth and survival of Gladiator swimming crabs in aquaculture systems. The study concluded that flow-through systems offer the most favourable environment for C. pallidus growth, particularly when combined with trash fish feeding. These results can inform future aquaculture practices and contribute to the sustainable production of Gladiator swimming crab in tropical regions.

Keywords: Advanced technology; trash fish; Ultra violet filter; production systems; crab aquaculture.

¹⁾ Higher Institution Centre of Excellent (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

² Department of Animal Sciences, University of Buea, Republic of Cameroon

³ Department of Aquaculture and Fisheries Management, University of Ibadan

Corresponding author*: mopaze2002@yahoo.com

Abstract

Shrimp farming is a key player in global aquaculture, driven by efficient and sustainable production technologies. Biofloc Technology (BFT) has emerged as a pivotal solution to various aquaculture challenges, offering a cost-effective and environmentally friendly approach. BFT enhances water quality by promoting the growth of heterotrophic bacteria, which help reduce ammonia levels and improve biosecurity. It also minimizes water exchange, conserving vital water resources in areas facing scarcity. However, while BFT has proven highly beneficial for shrimp farming, it presents challenges such as the risk of disease outbreaks, potential overcrowding, and management complexities. This review evaluates the advantages and limitations of BFT, highlighting its impact on water quality improvement, biosecurity enhancement, and water conservation. It also discusses the need for optimized system management to mitigate disease risks and overcrowding issues. Recommendations include the use of appropriate carbon sources for microbial mass management, species selection tailored to BFT, and potential integration of alternative energy sources to reduce operational costs. This review emphasizes BFT’s potential as a sustainable solution for small- and medium-scale aquaculture operations while acknowledging the necessity of addressing system challenges to maximize its efficacy.

Keywords: Aquaculture sustainability, Biofloc Technology, Disease management, Shrimp farming

Unit of Aquaculture, Ministry of Livestock, Fisheries and Animal Industries (Minepia), Cameroon

*Correspondence to: Email:dntombuh@yahoo.co.uk; tel: 0023766330000/675730100

ABSTRACT

 The fish feed production sector in the Centre and Littoral Regions of Cameroon faces several challenges that affect the quality of the feed produced and the growth rates of the fish. The drying and storage process of the feed is inadequate, leading to spoilage due to high moisture content. Most of the fish feed production units have a moisture content that ranges between 10.5% and 18.3%, which is higher than the recommended 10% or less. The cost of production has increased due to the high prices of both local and imported raw materials, such as soybean, corn, fishmeal, fish oil, rice, and wheat. The use of well-ground raw materials in fish feed formulation is essential for ensuring the overall quality of the feed and the growth rates of the fish. However, during visits to fish feed production units, it was found that 80% of them did not use well-ground raw materials. The lack of heating units or worn screws in extruders resulted in inadequate temperature control during the extrusion process, which affected the gelatinization of starches and proteins, leading to poor pellet formation, increased feed waste, and reduced feed efficiency. The fish feed produced did not meet the nutritional requirements of the fish, with more than 80% of the local feed analyzed having crude protein levels less than 30%. The local fish feed production sector faces intense competition from imported fish feed, leading to market saturation and reduced profitability for local producers. The lack of low-cost and readily available raw materials was another challenge that the fish feed industry faced. The nutritional composition labeled on fish bags did not match the results of the analysis after assessing some fish feed production units. Additionally, the cost of local or domestic fish feed per kilogram ranges from 1000CFA to 1100CFA, while imported feed costs between 1200CFA and 1400CFA. Despite the higher cost, 70% of fish farmers in Cameroon prefer to use imported fish feed due to its better feed conversion ratio, which they believe promotes the growth of their fish species. The local fish feed production sector faces several challenges that need to be addressed to improve the quality of the feed produced and the growth rates of the fish. Statistical analyses show that the sector needs to focus on improving the drying and storage process, using well-ground raw materials, and ensuring adequate temperature control during the extrusion process. The sector also needs to address the issue of low crude protein content in feed meals, the lack of low-cost and readily available raw materials, and the competition from imported fish feed. The government needs to provide support to the local fish feed production sector to improve its competitiveness and ensure food security.

Keywords: Fish feed production, Cameroon, challenges, quality, and growth rates.

Professional Master of Engineering in Fisheries and Aquatic Sciences, Option Aquaculture and Master of Science in HYDROBIOLOGY AND ENVIRONMENT, LABORATORY OF HYDROBIOLOGY AND ENVIRONMENT,

DEPARTMENT OF ANIMAL BIOLOGY AND PHYSIOLOGY, FACULTY OF SCIENCE, UNIVERSITY OF YAOUNDE I.

TANGEM LUCAS LEKU, OMGBA MARIE THÉRÈSE VIVIANE, MPOMEZOK CHILLY VANESSA GABY, NYAMA JOSEPH, TAMPONO IDEDOU CHRISTELLE.

MINISTRY OF LIVESTOCK, FISHERIES AND ANIMAL INDUSTRIES

YAOUNDE, CAMEROON.

Abstract

The study evaluated water quality and macroinvertebrate biodiversity in four (04) fish ponds at the Obili Aquaculture Unit, Centre Region of Cameroon, from June 2022 to November 2022. Monthly sampling was carried out, measuring physico-chemical parameters according to Rodier’s guidelines and collecting benthic macroinvertebrates using a multihabitat approach. Results indicated poorly oxygenated, slightly acidic water conditions, which are unfavorable for aquatic species production, along with low levels of organic pollution indicators such as nitrates, orthophosphates, and nitrites. A total of 532 macroinvertebrates were identified, spanning two phyla, two classes, six orders, and ten families. Insects dominated the community, comprising 51.7% relative abundance across four orders and eight families, followed by Gastropoda, which accounted for 48.3% relative abundance across two orders and two families. Spatial-temporal analysis revealed the presence of pollution-tolerant taxa, including Lestidae, Thiaridae, and Lymnaeidae, indicating excessive organic pollution. Diversity indices (Shannon-Weaver and Pielou’s equitability) reflected low taxa diversity, caused by unfavorable conditions for pollution-sensitive species. Hilsenhoff’s Biotic Index confirmed significant organic pollution across all ponds. The Global Biotic Numeric Index (GBNI) indicated poor water quality in the fish ponds, while Sörensen’s similarity coefficient (>50%) showed high similarity among ponds.

. Finally, the study suggests promoting macroinvertebrate cultivation as a viable alternative to fishmeal in aquaculture feed.

Key words: Biodiversity, Benthic Macroinvertebrates, Water quality, Fish ponds, Obili.

TANGEM LUCAS LEKU, OMGBA MARIE THÉRÈSE VIVIANE, MPOMEZOK CHILLY VANESSA GABY, NYAMA JOSEPH, TAMPONO IDEDOU CHRISTELLE.

MINISTRY OF LIVESTOCK, FISHERIES AND ANIMAL INDUSTRIES

YAOUNDE, CAMEROON.

Abstract

The study evaluated water quality and fish biodiversity in four fish ponds at the Obili Aquaculture Unit, located in the Centre Region of Cameroon, from June to November 2022. Monthly sampling was carried out, with physico-chemical parameters measured following Rodier’s guidelines. A multihabitat approach was used for fish capture, employing nets to sample and count fish, which allowed estimation of total fish populations in each pond. Results indicated poorly oxygenated and slightly acidic water conditions, unfavorable for aquatic species production, along with low levels of organic pollution indicators such as nitrates, orthophosphates, and nitrites. The African catfish, identifiable by barbels, absence of scales, a single long dorsal fin, and dark grey coloration with a white ventral side, was present in all ponds. Pond 4 was stocked at a density of 20 catfish per square meter, corresponding to an estimated 8,000 catfish, while only a few Tilapia were observed there. Oreochromis niloticus, an omnivorous grazer feeding on phytoplankton, periphyton, aquatic plants, small invertebrates, benthic fauna, detritus, and associated bacterial films, outnumbered catfish in the other ponds. Catfish stocking was aimed at controlling tilapia populations. The Global Biological Normalized Index (GBNI) indicated poor water quality across the ponds, whereas Sørensen’s similarity coefficient (exceeding 50%) demonstrated good biological similarity among the ponds. Finally, the study suggests promoting macroinvertebrate cultivation as a viable alternative to fishmeal in aquaculture feed.

Key words: Biodiversity, fish, water quality, fish ponds, Obili.

^aDepartment of Development studies of the Pan African Institute for Development West Africa (PAID-WA), Buea with Development with specialization in Agriculture and Development

^bMinistry of Agriculture and Rural Development

^cFaculty of Science,University of Dschang,

correspondence:bernardanjoika@gmail.com; Tel:00237675895735

ABSTRACT

                The high domestic demand for maize, which can be considered as a significant contributor to ensuring food security and health potential in Cameroon, contributed to motivate the interest to undertake this study and the resultant findings of the research. The study aims to investigate the result effect of maize variety and population density on the growth, physiological and yield response as well as the impact of adoption of improved maize varieties in Yaounde (vii) sub division center region of Cameroon. The five treatments (inter- row spacing) were: Treatment 1 (T115cm 195200 plants per hectare),Treatment 2 (T220cm-71400 plants per hectare), Treatment 3 (T325cm 57100 plants per hectare),Treatment 4 (T430cm47600 plants per hectare),Treatment 5 (T535cm40100 plants per hectare), Treatments were arranged in a randomized complete Block Design. Commercial N P K (20:10:10) fertilizer was applied after the development of five leaves by the plant. This research was conducted between June and July 2021. There were three blocks each with a surface area of 40 meters square. Each block was divided into three raised ridges. Each ridge measured 200cm by 0.5m. The ridges were separated from the adjacent ridge by 0.5m. Maize seeds were sown per intra- row spacing on 13^th of June 2021 after having observed consecutive rainfall. Data was collected on physiological, morphological and yield parameters. The data was subjected to ANOVA and the ordinary least square technique was the mean segregated method used to determine factors that influence maize yield. The results show that different intra- row spacing influence morpho-physiological abilities such as plant emergence, plant height, stem collar diameter, leaf area index, plant vigor and the yield parameters involving weight of cobs at harvest irrespective of the variety of the maize. Maize is the agronomic grass species that is most sensitive to variation in plant density. For each production system, there is a population that maximizes grain yield. This present an overview of the factors that affect optimum plant population, emphasizing on row spacing and variety on development and discussing important traits that have contributed to increase in yield of modern hybrids to specific, inter row spacing for maximum economic yield.

Key words: ANOVA: analysis of variance, ordinary least square techniques

                RÉSUMÉ

La forte demande intérieure de maïs, considérée comme un facteur important de sécurité alimentaire et de santé au Cameroun, a motivé l'intérêt suscité par cette étude et les résultats obtenus. L'étude vise à étudier l'effet de la variété de maïs et de la densité de population sur la croissance, la réponse physiologique et le rendement, ainsi que l'impact de l'adoption de variétés améliorées de maïs dans la sous-division de Yaoundé (VII), région du Centre, au Cameroun. Les cinq traitements (espacement inter-rangs) étaient les suivants : Traitement 1 (T115 cm - 195 200 plants par hectare), Traitement 2 (T220 cm - 71 400 plants par hectare), Traitement 3 (T325 cm - 57 100 plants par hectare), Traitement 4 (T430 cm - 47 600 plants par hectare), Traitement 5 (T535 cm - 40 100 plants par hectare). Les traitements ont été organisés selon un dispositif en blocs randomisés complets. Un engrais commercial N P K (20:10:10) a été appliqué après le développement de cinq feuilles par la plante. Cette recherche a été menée entre juin et juillet 2021. Il y avait trois blocs d'une superficie de 40 mètres carrés chacun. Chaque bloc était divisé en trois billons surélevés. Chaque billon mesurait 200 cm sur 0,5 m. Les billons étaient séparés du billon adjacent de 0,5 m. Les graines de maïs ont été semées selon un espacement intra-rang le 13 juin 2021 après avoir observé des précipitations consécutives. Des données ont été collectées sur les paramètres physiologiques, morphologiques et de rendement. Les données ont été soumises à une ANOVA et la technique des moindres carrés ordinaires était la méthode de ségrégation moyenne utilisée pour déterminer les facteurs qui influencent le rendement du maïs. Les résultats montrent que les différents espacements intra-rang influencent les caractéristiques morphophysiologiques telles que la levée, la hauteur, le diamètre du collet, l'indice foliaire, la vigueur et les paramètres de rendement, notamment le poids des épis à la récolte, quelle que soit la variété de maïs. Le maïs est l'espèce de graminée agronomique la plus sensible aux variations de densité de plantation. Pour chaque système de production, il existe une population qui maximise le rendement en grains. Cet article présente un aperçu des facteurs qui influencent la population optimale, en mettant l'accent sur l'espacement et la variété au cours du développement, et en analysant les caractéristiques importantes qui ont contribué à l'augmentation du rendement des hybrides modernes, en fonction d'un espacement spécifique entre les rangs pour un rendement économique maximal.

Mots clés : ANOVA : analyse de la variance, techniques des moindres carrés ordinaires