Cécile Annie EWANE

Antifungal, Antibacterial, Insecticidal and Nematicidal in vitro Activity of Four Plant-based Biopesticides

Mbang Gaston Elock, Abah Barakielle Arckange Bindzi, Meshuneké Arouna, Damien Fabrice Wassom, Onomo Pierre Effa, Cécile Annie Ewané

Biotechnology Journal International

Biopesticides are natural products used in agriculture to reduce the incidence or to eliminate crop pests. They represent an ecological and sustainable alternative to synthetic pesticides, the excessive use of which has serious impacts on human health and the environment. This work evaluates the efficacy of four plant based biopesticides against various plant pests, including insects (Aphidoidea, Zonocerus variegatus, Cosmopolites sordidus), fungi (Aspergillus flavus, Fusarium spp.), bacteria (Pseudomonas spp., Ralstonia solanacearum) and nematodes (Radopholus similis). Laboratory of Phytoprotection and Valorization of Genetic Resources of the Centre for Biotechnology, University of Yaounde 1, between March and June 2025. Four plant based biopesticides (BP1, BP2, BP3 and BP4) were prepared, and their effects were tested in vitro on target organisms. The results of the in vitro tests revealed significant repellent and lethal effects on insects, with repellent and mortality rates reaching over 70% after 48 h of exposure. Similarly, the biopesticides also showed marked antifungal (90-98%), antibacterial (64-93%) and nematicidal (100%) activities, inhibiting the growth of the target organisms and enzymatic synthesis (amylase and cellulase) in the tested fungi. These performances demonstrate that the four plant-based biopesticides (BP1, BP2, BP3 and BP4) possess strong insecticidal, antifungal, antibacterial and nematicidal potential that can be utilized in integrated pest management and sustainable agricultural production programs. Also, they reinforce the interest in biopesticides as sustainable alternatives to chemical pesticides, the use of which is increasingly restricted due to their toxicity to the environment and human health.

• #insect pest control strategies
• #insects and parasite interactions
• #agricultural practices and plant genetics
• #biopesticide

Antifungal, Antibacterial, Insecticidal and Nematicidal in vitro Activity of Four Plant-based Biopesticides

Mbang Gaston Elock, Abah Barakielle Arckange Bindzi, Arouna Meshuneké, Damien Fabrice Wassom, Onomo Pierre Effa, Cécile Annie Ewané

HAL (Le Centre pour la Communication Scientifique Directe)

International audience

• #insect pest control strategies
• #phytochemistry and biological activities of ficus species
• #agricultural practices and plant genetics
• #biopesticide

Effect of a Bioproduct Based on Tithonia diversifolia and Emilia coccinea on the Growth and Protection of PIF Plantains in Nursery

Gaston Elock Mbang, Arouna Meshuneké, Fabrice Damien Wassom, Aristide Dzelamonyuy, NICOLAS NIEMENAK, Cécile Annie Ewané

Cameroon Journal of Biological and Biochemical Sciences

Plantain is a staple food that contributes to food security in sub-Saharan Africa. However, its production remains insufficient due to various constraints, including parasitic pressure from Mycosphaerella fijiensis. This study aims to evaluate the effect of a bioproduct based on Tithonia diversifolia and Emilia coccinea on the growth and protection of PIF plantains. Two bioproduct modalities (B1 and B2) were produced, and treated PIF plants were generated. Bioproduct stability, in vitro test against Mycosphaerella fijiensis, growth parameters, susceptibility to Mycosphaerella fijiensis, and biomarker accumulation on PIF plantain leaves were evaluated. Growth was monitored for six months, and the leaves aged three and six months were taken at different periods (BI, 3AI and 28AI). The results show that the bioproduct was very stable and should be stored at room temperature away from light. The in vitro confrontation test revealed a very significant (P< 0.0001) inhibitory effect of the bioproduct on Mycosphaerella fijiensis growth. It stimulated explant germination as well as production of a large number of seedlings with significant increase in diameter, height and leaf surface area by 78.05%, 47.42% and 246.90% respectively compared to untreated seedlings. In addition, seedlings of different ages treated with the bioproduct showed very low sensitivity to Mycosphaerella fijiensis, especially those aged six months. Bioproduct treatment also significantly improved the accumulation of defense biomarkers before and after inoculation, with a greater effect observed three days after inoculation. The use of the bioproduct B2 appears to be effective and eco-responsible, and could be an effective tool for improving plant quality. Keywords: Biological product, Mycosphaerella fijiensis, PIF plantain, Growth and defense biomarkers.

• #medicinal plants and neuroprotection
• #phytochemical compounds biological activities
• #wood and agarwood research
• #mycosphaerella

Effect of a Biostimulant Based on Natural Products on the Growth of Plantain Bananas Plants under Field Conditions and on Fruit Quality

Abah Rosine Barakielle Arckange Bindzi, Mbang Gaston Elock, Meshuneké Arouna, Ndula Craftsman Ndula-Nan, Niemenak Nicolas, Cécile Annie Ewané

Biotechnology Journal International

Background & Aims: Plantains are consumed all over the world and are mainly grown extensively due to the unavailability of seeds in sufficient quantity and quality, disease and the high cost of agricultural inputs. Recent studies have highlighted the positive effect of biostimulants on seedlings growth promotion and protection in the greenhouse and the nursery such as plantains, cocoa, vegetables etc. The aim of our study is to confirm this positive effect of biostimulants on the agronomic performance of plants in the field, as well as their effect on the quality of fruit. Place and Duration of Study: Laboratory of Phytoprotection and Valorization of Genetic Resources of the Centre for Biotechnology, and the Laboratory of Biochemistry and Plant Physiology of Higher Teacher’s Training College, University of Yaounde 1, between November 2022 and January 2026. Methodology: The plants were watered with the biostimulant (BS), the positive control (NPK) and water (W) as negative control throughout their growth in the field until the fruit was obtained. We evaluated the agro-morphological parameters of the plants and the fruit treated. Results: The results obtained show that the biostimulant (BS) significantly improves the agronomic performance of plants and fruits compared to the positive control (NPK) and water (W). Indeed, it increases the diameter and the number of leaves of plants 2.2 and 1.1 times respectively compared to the controls (NPK) and (W). The accumulation of total phenols and total proteins in the leaves of plantain banana was 2 times more important in the leaves treated with biostimulant compare to the one treated with water, while it was 2.5 times more important for total sugars. Similarly, it improved flowering time, ripening time, total plant growth time, bunch weight, total number of fingers on hand 1, hand 1 weight and hand 2 weight 42.6 days, 23.1 days, 59.6 days, 4.3kg, 1.6, 1.2 and 0.5 times respectively compared with the controls (NPK) and (W). Conclusion: The biostimulant is thus an effective tool for promoting eco-responsible agriculture, a healthy, balanced organic plant feeding, good quality plantain fruit and the fight against poverty.

• #plant growth enhancement techniques
• #banana cultivation and research
• #plant physiology and cultivation studies
• #greenhouse

Effect of a Biostimulant Based on Natural Products on the Growth of Plantain Bananas Plants under Field Conditions and on Fruit Quality

Abah Rosine Barakielle Arckange Bindzi, Mbang Gaston Elock, Arouna Meshuneké, Craftsman Ndula-Nan Ndula, Nicolas Niemenak, Cécile Annie Ewané

HAL (Le Centre pour la Communication Scientifique Directe)

International audience

• #plant growth enhancement techniques
• #agriculture, plant science, crop management
• #silicon effects in agriculture
• #quality (philosophy)

Effect of Natural Plant-based Bio stimulants on the Growth and Protection of Cocoyam (Xanthosoma sagittifolium L. Schott)

Damien Fabrice Wassom, Mouhamed Noudi Lijouom, Gaston Mbang Elock, Rosine Barakielle Arckange Abah Bindzi, Arouna Meshuneké, Nicolas Niemenak and 1 more

Biotechnology Journal International

Background: Cocoyam (Xanthosoma sagittifolium L. Schott) is an important staple crop for food security worldwide. However, its cultivation faces several constraints, including the limited availability of planting material in both quantity and quality, as well as pests, diseases (root rot) and the inaccessibility of synthetic agricultural inputs. Aims: The objective of this study is to evaluate the effects of bio stimulants derived from natural plants on the growth and protection of cocoyam planting material. Place and Duration of Study: The study was conducted at the Laboratory of Phytoprotection and Valorization of Genetic Resources of the Centre for Biotechnology, and the Laboratory of Biochemistry and Plant Physiology of Higher Teacher’s Training College, University of Yaounde 1, between March and June 2023. Methodology: A randomized block design was applied in both environments, consisting of six treatments: four bio stimulants derived from natural plant sources (BS1, BS2, BS3, BS4), a chemical fertilizer (NPK 20.10.10) as a positive control, and water as a negative control. Red and white cocoyam planting materials were watered with bio stimulants at 25% from pre-emergence in the greenhouse to emergence under shade conditions, then their effects were evaluated and correlated with agromorphological parameters, as well as growth and defense biomarkers. Statistical analyses included ANOVA with Tukey’s test (5% significance), multi-factor analysis for growth parameters, and Pearson correlation tests. Results: bio stimulants very significantly stimulated (P< 0.0001) seedling pre-emergence and emergence in terms of agromorphological parameters (number of shoots, stem diameter and height, number of leaves and leaf area) and the accumulation of growth- and defense-related biomarkers (total chlorophylls, total sugars, total phenols, flavonoids, total proteins, PAL, POX and PPO) compared with the positive (C+) and negative (C−) controls. In both varieties, bio stimulants increased the number of shoots by 56.75-92.71%, stem diameter by 77.92-93.33%, stem height by 65.73-96.02%, number of leaves by 72.50-90%, and leaf area by 36.05-82.52%. Biomarker contents ranged between 0.022 and 227.917 mg/g FM, while defense-related enzyme activities ranged between 0.036 and 0.407 µmol/min/mL compared with the controls. BS2 was the most effective treatment across all responses in both red and white cocoyam. Conclusion: These results suggest that bio stimulants may stimulate plant metabolism and biological processes, while also improving nutrient uptake. They could therefore constitute an effective tool for the biofortification, the promotion of environmentally sustainable agriculture and poverty alleviation.

• #plant growth enhancement techniques
• #plant growth and agriculture techniques
• #cocoa and sweet potato agronomy
• #sowing

A bioformulation of oyster shell, neem, sida, and citronella extracts boosts cocoa (Theobroma cacao L.) seedling development and resistance to black pod disease caused by Phytophthora megakarya

Ebenezer Tatiekam Foka, Tatiana Flore PACHA MAGNI, Paul Martial Téné Tayo, Aristide Dzelamonyuy, Pierre Effa Onomo, Thaddée Boudjeko and 1 more

Journal of Natural Pesticide Research

Phytophthora megakarya is the major destroyer of cocoa production in Central and West Africa. The present study evaluated the efficacy of a bioformulation called Optimized Bio Formulation Prime (OBF') containing oyster shell extract and plant extracts (neem seed, sida weed and citronella) with tween80, on cocoa seedling production. The formulation was tested for stability and activity and it appears that it is stable at 25 o C and reduces the growth of Phytophthora megakarya by 55% when used at 1 µL/mL. OBF' exerts its fungicidal activity by inhibiting protein synthesis and ATPase/H + pump activity of Phytophthora megakarya . The GC-MS analysis of OBF' showed the presence of compounds among which citral and geraniol which have antimicrobial and insecticidal activity. After two weeks, the length and number of secondary roots of the germinated seeds had significantly increased. In addition, the use of OBF' in the in planta assay significantly increased leaf surface area. Detached leaf analysis of these seedlings showed a significant reduction in disease severity index of about 79% compared to untreated plants with OBF'. It was found that OBF' induce PR proteins such as β-1,3-glucanases and peroxidases. A significant increase in polyphenol and polyphenol oxidase activities was also observed in OBF' treated plants. This work demonstrated the stability at 25°C and the efficacy of the OBF' formulation in the management of cocoa black pod disease and, subsequently, increasing the robustness of cocoa plant seedlings against Phytophthora megakarya by priming them with increased defense markers. OBF’ may help to protect cocoa seedlings production.

• #cocoa and sweet potato agronomy
• #food chemistry and fat analysis
• #plant parasitism and resistance
• #phytophthora

Effect of Biostimulants Based on Natural Products on the Growth and Nutritional Value of Bean (<i>Phaseolus</i> <i>vulgaris</i> L.)

Aimé Giresse Tzeuton, Flore Eliane Eyenga, Arouna Meshuneké, Gaston Mbang Elock, Fabrice Damien Wassom, Walter Jospin Timma Kom and 7 more

American Journal of Plant Sciences

Beans (Phaseolus vulgaris L.) are widely grown in Cameroon and play a key role in the fight against food insecurity, malnutrition and poverty. However, its cultivation encounters problems due to abiotic and biotic stresses, which leads to the use of synthetic fertilizers and pesticides, which cause significant damage to the environment and human health due to the presence of synthetics residues in the seeds, pods and in the leaves that are eaten. Promoting the use of natural products is becoming a necessity for organic and eco-responsible agriculture that limits contamination problems and improves people’s purchasing power. This study aims to assess the effect of biostimulants based on natural products on the growth and nutritional value of common bean (Phaseolus vulgaris L.). Bean seedlings from white variety (MEX-142) and red variety (DOR-701) were treated every seven days in the field from their pre-emergence, emergence and growth to their maturation under a randomized block experimental design. Six treatments and three repetitions with the biostimulants based on natural products and controls were thus performed and the agromorphological parameters were measured. After 120 days, the contents of growth biomarkers and defense-related enzymes were evaluated in leaves, while the contents of macromolecules, minerals and antinutrients were evaluated in seeds. These biostimulants significantly increased (P P < 0.0001) of antinutrients including oxalates, phytates, tannins and saponins in seeds compared to controls (T+ and T−). Treatment with biostimulants, in particular BS4, improves the performance of bean plants in the field as well as the biofortification of seeds regardless of the variety.

• #plant growth enhancement techniques
• #phytase and its applications
• #seed germination and physiology
• #phaseolus

Biofungicide Based Calcium, &amp;lt;i&amp;gt;Azadirachta indica&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;Sida acuta&amp;lt;/i&amp;gt; Against &amp;lt;i&amp;gt;Phytophthora megakarya&amp;lt;/i&amp;gt;

Ebenezer Tatiekam Foka, Paul Martial Téné Tayo, Tatiana Flore Magni Pacha, Aristide Dzelamonyuy, Sylvain Leroy Kamdem Sado, Pierre Effa Onomo and 2 more

Plant pesticides are a complementary means to other control methods and an alternative to chemical control. The identification of potential plants that can be used in plant protection against pests is increasing enormously, but the availability of bioformulations is low. The new products developed for plant protection aim to protect them against a larger range of pathogens and include elicitors. The objective of this study is to produce an optimal emulsion bioformulation based on neem (<i>Azadirachta indica</i> A. Juss.), Sida (<i>Sida acuta</i> Burm. F.) and calcium, that can be used for plant protection against pests. The surface plot of the four factor simplex lattice designs data help to construct significant linear models for stability and activity. The best formulation was selected and optimize. The four Factor mixture designs and stability as well as activity models showed that the best formulation has neem oil (No) 12% (v/v), neem aqueous extract (Ne) 9% (w/v), sida weed hydroalcoholic extract (Se) 9% (w/v), Oyster shell’s calcium-rich extract (Ca) 6% (w/v) and tween-80 (Tw) 24% (v/v) with the production process “AQ + (Tw+No)”. Therefore, the optimize formulation has No 12% (v/v), Ne 9% (w/v), Se 9% (w/v), Ca 4.5%(w/v), calcium oxide (CaO 1.5% (w/v) and Tw 24% (v/v) with the production process “(Tw+No) + AQ”. The best formulation and the optimize one at ambient temperature have 100% of stability and a significant dose dependent activity (<I>P</I> <0.05) against plant pathogens. Apply optimize formulation at 1% on the detached cocoa leaves before inoculation with <i>Phytophthora megakarya</i> reduces disease severity index from 4.2 to 1.5. These results suggest that our models and bioformulation can be useful for <i>T. cocoa</i> protection against <i>P. megakarya</i>, the causal agent of black pod disease.

• #plant pathogens and resistance
• #agriculture, plant science, crop management
• #seed and plant biochemistry
• #adenylate kinase

&amp;lt;i&amp;gt;Tithonia diversifolia&amp;lt;/i&amp;gt; Leaves and Stems Use as Substrate Amendment Promote the Growth of Plantain Vivoplants in the Nursery

Cécile Annie Ewané, N. T. Mbanya, Thaddée Boudjeko

Agricultural Sciences

Tithonia diversifolia is a year-round weed that decomposes rapidly after application as a soil amendment and it is more and more used in agriculture due to its numerous properties. The use of Tithonia diversifolia in the production of plantain vivoplants is a great opportunity for small holders’ farmers that cannot easily buy chemical inputs for yield improvement. All plant parts are used because of their richness in nutrients, mineral elements and phytochemicals without knowing which part is the most efficient. Tithonia diversifolia used as substrate amendment for plantain vivoplants production in nursery could promote their growth. This study aims to evaluate the effect of T. diversifolia leaves and stems as substrate amendment on plantain vivoplants growth promotion. The vivoplants were produced in substrates amended with T. diversifolia leaves, stems, combination of leaves and stems, and control without amendment. The vegetative growth parameters (number of shoots, height and diameter of shoots, area of shoots leaves) were assessed in sterilized substrate and unsterilized substrate conditions. T. diversifolia leaves and stems treatment increases the number of shoots, the height and the diameter of shoots as well as the area of shoots leaves compared to the control. T. diversifolia stems are the more efficient treatment, followed by the combination of T. diversifolia leaves and stems and finally the T. diversifolia leaves. They act as a biofertilizer promoting thus, the growth of plantain vivoplants in the nursery. All parts of Tithonia diversifolia can therefore be used by poor small holder farmers, as green manure for soil amendment in a green agriculture context.

• #plant tissue culture and regeneration
• #medicinal plants and neuroprotection
• #tithonia
• #amendment

Evaluation of antagonistic activities against Pythium myriotylum and plant growth promoting traits of Streptomyces isolated from Cocoyam (Xanthosoma sagittifolium (L.) Schott) rhizosphere

Peguy Flora Djuidje Kouomou, Cécile Annie Ewané, Sylvain Lerat, Denis Omokolo Ndoumou, Carole Beaulieu, Thaddée Boudjeko

Australian Journal of Crop Science

The focus of this study was to isolate, evaluate and characterize cocoyam rhizospheric actinobacteria collected from Mount Cameroon for their potential antagonistic activities against Pythium myriotylum, the causative agent of cocoyam root rot disease, and/or their ability to promote plant growth. Actinobacteria were isolated from soil samples by using serial dilution method. Dual culture assay was used to screen the isolates against fungal phytopathogens including P. myriotylum. The selected isolates were characterized morphologically, physiologically, biochemically and genetically. Furthermore, these isolates were subjected to in vitro production of various plant growth promoting (PGP) traits. Among the 287 isolates distributed into 12 distinct groups, PFK4, PFBOT7 and PFEL2 had high antagonistic effects against P. myriotylum and they were regarded as promising candidates for further study of their biocontrol ability. The identification of actinobacterial isolates was done using universal PCR of partial 16S rRNA sequences combined with bioinformatics and phylogenetic procedures. The results revealed that all these isolates belong to the genus Streptomyces spp. The isolate PFK4 showed 99% similarity with Streptomyces albulus while PFBOT7 showed 99% similarity with Streptomyces albus and PFEL2 showed 98% similarity with Streptomyces gandoceansis based on their 16S rRNA gene sequences. In this study for the first time, we report S. gandocaensis strain for the biological control of Pythium myriotylum. The role of these isolates in Plant Growth Promotion (PGP) by in vitro production of PGP traits such as phosphate solubilisation, siderophore, indole-3-acetic acid (IAA), ACC deaminase and cell wall degrading enzymes production were also evaluated and showed as potential PGP agents. Concurrent production of PGP substances coupled with broad spectrum of antifungal and antibacterial activities of these three strains suggest their potential use as promising biocontrol and PGP tools for the development of an alternative control method for cocoyam cultivation.

• #plant-microbe interactions and immunity
• #studies on chitinases and chitosanases
• #biology
• #actinobacteria

Impact of the extension of black leaf streak disease on banana susceptibility to post-harvest diseases

Cécile Annie Ewané, Marc Chillet, Florence P. Castelan, Yves Brostaux, Ludivine Lassois, Josué Essoh Ngando and 4 more

Fruits

la diffusion de documents scientifiques de niveau recherche, publis ou non, manant des tablissements d'enseignement et de recherche franais ou trangers, des laboratoires publics ou privs.

• #banana cultivation and research
• #plant pathogens and fungal diseases
• #pineapple and bromelain studies
• #streak

Involvement of phenolic compounds in the susceptibility of bananas to crown rot. A review

Cécile Annie Ewané, Philippe Lepoivre, Luc De Lapeyre de Bellaire, Ludivine Lassois

Agritrop (Cirad)

Crown rot of bananas, caused by a fungal parasitic complex, is one of the main quality defects of exported bananas. Major variations in the susceptibility of bananas to crown rot have been observed in different production zones. The physiological state of the banana fruit at harvest is said to influence its response to pathogenic attack and thus to modulate its susceptibility to crown rot. The susceptibility of bananas to this disease, however, appears to be influenced by many pre-harvest factors, although the underlying defense mechanisms have not been clearly identified. A recent report based on molecular analyses suggests that phenolic compounds might be involved in the different variations in the susceptibility of bananas to crown rot. Results of other earlier studies point to an involvement of phenolic compounds in the defensive reactions of banana plants against various pathogens. The present paper reviews the current state of knowledge on the variations in the susceptibility of bananas to crown rot and takes stock of what is known about phenolic compounds in relation to their potential involvement in the defense mechanisms of the banana plant.

• #banana cultivation and research
• #postharvest quality and shelf life management
• #plant physiology and cultivation studies
• #forestry

Study of the physiological component involved in the development of crown rot in bananas and the role of phenolics in susceptibility variation mechanisms

Cécile Annie Ewané

Agritrop (Cirad)

La pourriture de couronne est une maladie de conservation qui affecte de façon importante la qualité des bananes d'exportation au Cameroun comme dans la plupart des zones de production. Elle est due à un large complexe parasitaire peu spécifique et opportuniste. L'approche originale de cette étude a été d'abord de mieux comprendre les conditions entourant le développement de la maladie et les facteurs de variation de la sensibilité des fruits, puis de caractériser le contenu phénolique des couronnes de bananes à sensibilité différentielle. Cette thèse a pour objectif de montrer l'influence des facteurs abiotiques et biotiques sur la composante physiologique du fruit à la récolte et l'implication des composés phénoliques dans les mécanismes mis en jeu dans les variations de sensibilité des fruits à cette pathologie. Au terme de cette étude, il apparait que les facteurs abiotiques et biotiques influencent la composante physiologique du fruit à la récolte, affectant ainsi le niveau de sensibilité des fruits et par conséquent le développement des pourritures de couronne. Au préalable, la fiabilité de la méthode d'estimation des surfaces nécrotiques (INS) a été améliorée. L'influence des facteurs abiotiques (zone de production et date de récolte) sur le niveau de sensibilité des fruits à la pourriture de couronne a été démontrée mais pas celle des variations saisonnières. Les bananes cultivées en zone d'altitude (Ekona, 500 m) sont moins sensibles que celles cultivées en basse altitude (Dia-Dia, Koumba, 80 m). A certaines dates de récolte pendant la saison de pluies, la sensibilité des fruits était élevée en basse altitude. L'influence des facteurs biotiques (parasites foliaires) sur le niveau de sensibilité des fruits aux pourritures de couronne a été démontrée dans deux zones géographiques. Au Cameroun, la maladie des raies noires influence significativement (P&amp;lt; 0.001) la sensibilité des fruits à la pourriture de couronnes. En Guadeloupe, la maladie de Sigatoka n'a aucune influence (P&amp;gt; 0.05) sur le developpement des pouritures de couronne. L'influence des variations de ratio source-puits (So-Si, facteur abiotique), sur la physiologie du fruit pourrait expliquer cette différence. II L'influence de la modification sévère des ratios source-puits sur la sensibilité des fruits à la pourriture de couronne a été démontrée. Les fruits à faible ratio source-puits étant les plus sensibles. Les bananes de modalités extrêmes (12feuilles/1main, 1feuille/8mains) et à sensibilité différentielle (S-, S+) à la pourriture de couronnes ont été utilisées pour la caractérisation biochimique de leur contenu phénolique par les méthodes chromatographiques (GC-MS, HPLC et LC-MS) à deux stades : le jour de récolte avant inoculation (dhbi) et 13 jours après inoculation (13dpi). La dopamine a été identifiée comme étant le métabolite secondaire (alkaloïde phénolique) majoritaire des couronnes de bananes. La norépinéphrine et la normétanéphrine ont été détectées en grande quantité dans les couronnes fraichement récoltés et non inoculées (dhbi), particulièrement dans les couronnes sensibles (S+). Certains composes phénoliques ont été détectés en quantité plus importante dans les couronnes de bananes les moins sensibles (S-) comparées aux fruits plus sensibles (S+). Il s'agit des acides hydroxycinnamiques (acide férulique, acide coumarique et leurs dérivés), ainsi que d'autres composés non identifiés, accumulés le jour de récolte (dhbi) en quantité importante dans les couronnes les moins sensibles (S-) par rapport aux bananes sensibles (S+), mais cette quantité diminue 13dpi de manière plus importante chez les fruits sensibles (S+). Ces résultats suggèrent une possible implication des composés phénoliques dans la défense biochimique des couronnes de banane. Toutefois, le rôle précis de chacun de ces composés phénoliques dans le mécanisme de variations de sensibilité à la pourriture de couronnes n'est pas encore clarifié. Cette étude est le point de départ

• #banana cultivation and research
• #forestry
• #humanities
• #geography

Pre-harvest conditions affect the banana susceptibility to post-harvest disease : [Abstract of poster]

Ludivine Lassois, Cécile Annie Ewané, Marie Forret, M. Haïssam Jijakli, Luc De Lapeyre de Bellaire

Agritrop (Cirad)

• #banana cultivation and research
• #affect (linguistics)
• #biology
• #horticulture

Pre-harvest conditions affect the banana susceptibility to post-hervest disease.

Ludivine Lassois, Cécile Annie Ewané, Marie Forret, Haïssam Jijakli, Luc De Lapeyre de Bellaire

Open Repository and Bibliography (University of Liège)

• #banana cultivation and research
• #affect (linguistics)
• #business
• #psychology

Is air-displacement plethysmography a reliable method of detecting ongoing changes in percent body fat within obese children involved in a weight management program?

Cécile Annie Ewané, Stacy A. McConkey, Clarence D. Kreiter, Mathew Fuller, Ann Tabor, Jacqueline M. Van Den Bosch and 3 more

Obesity Research & Clinical Practice

• #body composition measurement techniques
• #non-invasive vital sign monitoring
• #thermal regulation in medicine
• #medicine

Relation entre la présence de la cercosporiose noire sur le bananier et l'apparition des maladies de conservation des bananes au Cameroun

Cécile Annie Ewané, Luc De Lapeyre de Bellaire, Yves Brostaux, Denis Omokolo Ndoumou, Philippe Lepoivre

Agritrop (Cirad)

• #banana cultivation and research
• #forestry
• #geography

The post-harvest quality of bananas is determined by pre-harvest factors

Luc De Lapeyre de Bellaire, Marc Chillet, Ludivine Lassois, Cécile Annie Ewané, Héloïse Bastiaanse, M. Haïssam Jijakli and 1 more

Anthracnose of bananas, caused by Colletotrichum musae and crown rot of bananas, caused by a broad unspecific parasitic complex; are the most important post-harvest diseases affecting the quality of exported bananas. These diseases develop during fruit transportation, conservation, ripening and marketing. Like for most post-harvest diseases, the control of these diseases relies mainly on post-harvest practices like fungicide applications, cooling, etc... Nevertheless, seasonal and spatial variations in the performance of these practices highly depend on the elaboration of a potential of fruit quality at field level. This potential of fruit quality is constituted by a physiological component (the fruit susceptibility) and a parasitic component (the level of fruit contamination). Recent work has shown the importance of these pre-harvest factors as important determinants of post-harvest quality of bananas. Referring to the parasitic component, it has been shown, in the case of anthracnose, that floral remnants are the main inoculum sources for fruit contamination by Colletotrichum musae, and that most contaminations occur very early in the field, during the first month of bunch emergence. Referring to the physiological component, fruit grown in highland areas are less susceptible to anthracnose and also to crown rot diseases than fruit grown in lowland areas. By another hand, it has been shown that the physiological age of fruit at harvest has also a strong influence on fruit susceptibility to both diseases: the youngest the fruits, the less susceptible. Lastly, the modification of source-sink ratio (leaf or fruit trimming), influences fruit susceptibility to crown rot but has no influence on fruit susceptibility to anthracnose. These results suggest that alternative methods to control these post-harvest diseases of bananas should take into account these pre-harvest factors. (Resume d'auteur)

• #banana cultivation and research
• #plant physiology and cultivation studies
• #ripening
• #biology

Variation factors of bananas susceptibility to crown rot in Cameroon

Cécile Annie Ewané, Luc De Lapeyre de Bellaire, Yves Brostaux, Denis Omokolo Ndoumou, Philippe Lepoivre

Agritrop (Cirad)

• #banana cultivation and research
• #crown (dentistry)
• #variation (astronomy)
• #biology

Etude de la biodiversité de la microflore des eaux de lavage des bananes en station de conditionnement et relation avec la manifestation de la pourriture de couronne au Cameroun

Cécile Annie Ewané

Agritrop (Cirad)

L'analyse microbiologique de l'eau des bacs de dépattage et de lavage des bananes en station d'emballage a été effectuée pendant 9 semaines sur deux stations différentes au Cameroun. Il existe une différence quantitative et qualitative de la composition de la microflore des eaux des bacs de lavage des bananes entre les deux stations et entre les deux types d'eau de lavage. La concentration en spores est plus élevée à Dia-dia qu'à Tiko. De plus les concentrations en spores sont supérieures à Dia-dia dans les eaux de dépattage par rapport aux eaux de lavage. Cette différence de concentration en spores proviendrait du mode de traitement des eaux de ces stations. Suite à l'identification morphologique et moléculaire, les espèces fréquemment isolées des eaux des bacs de lavage des bananes au Cameroun sont Penicillium spp., Verticillium sp., Céphalosporium sp., Cladosporium sp., Fusarium monoliforme, Fusarium sp. Trichoderma sp., Colletotrichum sp. Le pouvoir pathogène des eaux de dépattage a été évalué en présence de témoins. L'apparition de nécroses sur les couronnes inoculées avec de l'eau stérile confirme l'existence en leur sein d'infections préétablies. Le pouvoir pathogène des eaux de dépattage est identique quelque soit la région et est très faible par rapport à celui du témoin C. musae. Ce faible pouvoir pathogène pourrait s'expliquer par la diversité de la microflore et l'existence des relations antagonistes au sein du complexe parasitaire. Le pouvoir pathogène des espèces le plus fréquemment isolées des eaux des bacs de dépattage et de lavage des bananes a été évalué en présence d'un témoin C. musae. Le pouvoir pathogène de C. musae est de loin supérieur à celui des autres pathogènes. Aucune corrélation n'a été établie entre les variations de la nature du complexe parasitaire et du pouvoir pathogène des eaux des bacs de lavage entre les deux stations d'étude et les deux types d'eaux de lavage au cours du temps.

• #banana cultivation and research
• #forestry
• #spore
• #biology