Field management of Taro (Colocasia esculenta (L.) Schott) leaf blight via fungicidal spray of foliage

Taro leaf blight (TLB) epidemic hit Cameroon for the first time in 2009. Since then, the disease is persistent and its typical devastating legacy is threatening Taro (Colocasia esculenta) in the North and South West Regions of Cameroon. This study was initiated with the objective to determine the potentials of some fungicides to control TLB. The experimental design was completely randomized with a 3x15x2 factorial, including 3 treatments: T1 (Callomil plus72WP), T2 (Mancoxyl plus 720WP) and T3, 1:1 ratio T1 + T2 all applied at concentrations of 4g/L; 15 repetitions and 2 planting seasons (dry season i.e. October 2014 – March 2015 and rainy season i.e. April-October 2015). Disease incidence and disease severity were used to evaluate the disease progression while corm yield was used to appraise the economic injury. The results revealed disease incidence of 0% during the dry season and 18.2%, 27.3% and 100%, for T1, T2 and T3 and control during rainy season respectively. Disease severity was 75% in control and only 1% for the different treatments. Corm yield in the rainy season was 17.4kg, 15.08kg, 14.27kg and 5.89kg for T1, T2, T3 and control respectively. This study suggests that TLB epidemic can effectively be managed by foliage spray with Metalaxyl containing fungicides at a weekly dosage of 4g/L. Key words: Chemical control, Colocasia esculenta, Epidemic, Phytopathology, Phytophthora colocasia

Seed Dormancy: Induction, Maintenance and Seed Technology Approaches to Break Dormancy

Dormancy is the major cause of erratic germination, patchy emergence and uneven seedling establishment in the field. These traits are exceedingly undesirable in crop production as future phases of growth and development are strongly linked to uniform seedling development at early growth phases. Variations in maturation time, and difficulty in managing abiotic and biotic stresses during pre- and postharvest are common consequences of uneven germination and seedling emergence. Minimizing this negative impact of dormancy in a seed lot is the major concern of all seed production companies. Generally, mature seeds show some considerable dormancy during which embryo growth is halted momentarily because one or more internal and external stimuli for growth resumption is/are absent. If the inhibition of seed germination is solely due to insufficient or complete absence of external signals, then the seed is in a state of quiescence. Otherwise, if linked to internal factors, then the seed is in a state of dormancy. Induction, maintenance, and release of dormancy are therefore related to Seed-dependent factors such as morphology, hormones, state of embryo maturity at seed dispersal and chemical inhibitors. This chapter focuses on species-dependent methods currently used to break dormancy, reduce germination time and improve emergence and seedling establishment

Etude de l’Origine et de L’Identité de quelques Types d’Huiles Végétales Raffinées Commercialisées à Douala/Cameroun

Les huiles végétales raffinées sont des sources d’énergie, d’acides gras essentiels, d’antioxydants et de vitamines liposolubles. Elles permettent de lutter contre la malnutrition et le vieillissement cellulaire. Les mauvaises conditions d’extraction, de raffinage, de conservation et de stockage peuvent altérer l’identité et la qualité de ces produits. L’objectif de ce travail était d’évaluer l’origine et l’identité de 56 échantillons d’huiles végétales commercialisées à Douala. Pour ce faire nous avons étudié la représentativité des variétés d’huiles sur le marché et leur origine, l’indice d’iode, l’indice de saponification et la conformité de l’étiquetage. Les résultats montrent que le marché des huiles végétales raffinées est dominé par les produits importés avec 57,2% de part de marché. Moins de 30% des échantillons analysés étaient conformes à la norme camerounaise NC 04 :2000-20sur l’étiquetage des denrées alimentaires pré emballées. Aucun échantillon analysé n’a eu un indice d’iode, ni de saponification, conforme à la norme du Codex Alimentarius et la norme camerounaise NC 77 : 2002-03, REV.1. de 2011 portant sur les huiles végétales enrichies en vitamine A. Les huiles raffinées analysées auraient été adultérées ou auraient subies une altération avancée par le phénomène d’auto oxydation catalysé par la chaleur. Elles ne seraient pas des corps gras purs. Cette étude suggère que des efforts considérables doivent être entrepris en plus des acquis dont dispose le Cameroun dans le domaine du contrôle de qualité des denrées alimentaires.Mots clés: Huiles végétales, Contrôle Qualité, Norme, Conformité d’étiquetageEnglish AbstractRefined vegetable oils are sources of energy, essential fatty acids, antioxidants and fat-soluble vitamins. They help fight against malnutrition and cellular aging. Poor extraction, refining, storage and storageconditions can alter the identity and quality of these products. The objective of this work was to evaluate the origin and identity of 56 vegetable oil samples marketed in Douala. We studied the representativenessof the different oil varieties from the market and their origin, the iodine index, the saponification index and the conformity of the labeling. The results show that the market for refined vegetable oils is dominated by imported products with a 57.2% market share. Less than 30% of the samples analyzed complied with the Cameroonian standard NC 04: 2000-20 on the labeling of prepackaged foods. No samples analyzed had an iodine or saponification index in accordance with the Codex Alimentarius standard and the Cameroonian standard NC 77: 2002-03, REV.1. Of 2011 on vegetable oils fortified with vitamin A. The refined oils analyzed were adulterated or might have undergone advanced alteration by the phenomenon of auto-oxidation catalyzed by heat. These oils are therefore not really pure fats. This study suggests that considerable efforts must be made in addition to Cameroon’s achievements in the field of quality control of foodstuffs.Keywords: Vegetable Oils, Quality Control, Norms, Labeling Complianc

Polymer selection for microencapsulation of probiotics: impact on viability, stability, and delivery in functional foods for improved manufacturing and product development in the food industry

Probiotics have won considerable interest in the food industry because of their health benefits. However, ensuring probiotics' viability, stability, and effective delivery in functional ingredients constitute a major concern. Microencapsulation is a promising method to ensure probiotic viability and stability. The best polymer for microencapsulation of probiotics is a determining factor. This paper presents an overview of the impact of polymer selection on probiotic viability, stability, and delivery in functional foods. It discusses numerous microencapsulation techniques and factors influencing polymer selection. It further explores the consequences of various polymers on probiotic viability, highlighting their protecting mechanisms. Additionally, it examines the role of polymer selection in enhancing probiotic stability during delivery, launch kinetics, storage and processing. The business packages of microencapsulated probiotics in foods and case studies on precise polymer choices for probiotic product improvement are also presented. Finally, we present challenges and future directions in using polymers for probiotic microencapsulation in the food industry. This review thus presents insights to enhance manufacturing tactics and product development within the food industry

Transcriptional expression of three putative pathogenesis-related proteins in leaves of rubber tree (Hevea brasiliensis) inoculated with Neofusicoccum ribis

Pathogenesis related-proteins (PR-proteins) and enzymes are important tools for understanding the molecular markers of plant response to external factors. In this study, semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was optimized to detect the expressions of two PR-proteins and one enzyme extracted from the leaf RNA of two rubber clones (PB 350 and RRIM200) at four-period intervals. The expression patterns of enzymes β-1,3-glucanase (Glu), chitinase (Chit), and phenylalanine ammonia lyase (PAL) in the leaf tissues of the clones RRIM 2002 and PB 350 to Neofusicoccum ribis were expressed by up and down regulations and varied with time. The trial inoculation indicated that the gene expressions were significantly higher in tolerant clones (RRIM 2002) than in the susceptible clones (PB 350). Gene expression analysis of the biomarkers revealed that the earlier detection markers in infections occurred within 5–10 days post infection and showed significant correlation with disease development, ranging from 1.67–3% in the RRIM 2002 clone and approximately 8.33% in the PB 350 clone. This is the first study on the infection and up-regulation of gene expression in rubber leaves infected with N. ribis isolate SK10 (ICMP 20078). This study showed the importance of exploring the SK10 isolate as an indicator of infection ability and positive fungal–host interaction

CONFCAYS 2019 & Sub Regional Training Workshop on Science AdviceScience Advice in Africa: Opportunity or illusion: Young Scientists: Mainspring of innovation and development in Africa

International audienceThe Cameroon Academy of Young Scientists (CAYS) is a branch of the Cameroon Academy of Science (CAS) aimed at promoting research, paving the way for young scientists, encouraging the development of innovative approaches to national and international challenges. CAYS is a forum for building scientific capacities and the applicability of science to solve problems and provide decision makers and the public with advice based on the most up-to-date scientific knowledge. With support from MINRESI, MINTOUR, MINESUP, CAS, AUF and other partners, CAYS is organizing it first biennial international conference under the theme «Young Scientists: Mainspring of innovation and development in Africa » where scientists have opportunities to present their research results on diverse topics. More and more, scientific advice is spreading the world over to assist policy makers and politicians to make decisions that are informed by evidence-based data and scientific knowledge. It is an opportunity for dialogue that breaks or limits the gaps between researchers in different fields. In Africa and particularly in the Central African Sub-region, the progress of this concept is still lagging behind. Taking cognizance of this, CAYS offers an opportunity, during this conference, of a training workshop on the science advice in collaboration with The Quebec Research Funds (FRQ) and the International Network for Government Science Advice (INGSA). For the workshop, 65 participants were selected from government institutions and civil society organizations in the Central African Region. A total of 153 abstracts (55 oral and 98 poster presentations) were selected from national and international participants. The said abstracts will be presented in 4 sessions under 3 major themes including 1) Nutrition, Health and Environment; 2) Material Science, ITC and Renewable Energy; and 3) Digital Economy, Peace and Development. These abstracts have been compiled in this abstracts volume

Susceptibility of rubber (Hevea brasiliensis) clones to Neofusicoccum ribis

The aim of this study was to evaluate the ability of Neofusicoccum ribis to infect leaf surfaces of different rubber (Hevea brasiliensis) clones. Neofusicoccum ribis isolates previously identified on the basis of morphological characteristics and DNA sequence analysis were used to inoculate rubber leaves and seedlings in vitro and in vivo respectively. Neofusicoccum ribis isolates were demonstrated to cause lesions on rubber clones examined in this study. There was variation in susceptibility of the rubber clones to the pathogen. This study provides useful information that could be exploited to better manage the disease

Advancements in nano bio sensors for food quality and safety assurance – a review

Nano-biosensors are rising as a promising technology for ensuring the protection and high-quality of meals merchandise. They offer excessive sensitivity, selectivity, and speedy reaction, making them ideal for detecting contaminants, pathogens, and first-rate signs in meals samples. This up to date evaluate affords a complete evaluation of recent improvements in nano-biosensor technology for meals great and safety warranty. The evaluate covers the essential standards and kinds of nano-biosensors typically utilized in meals evaluation, exploring various nanomaterials and their unique homes and sensing talents. It also discusses mixing nanomaterials with biological reputation elements, antibodies, enzymes, and DNA aptamers to enhance sensor performance. The software of nano-biosensors in detecting chemical contaminants, which includes pesticides, heavy metals, and mycotoxins, is drastically protected. Nanomaterials allow ultrasensitive detection of these contaminants, even at trace stages, ensuring the protection and compliance of meal products. The review also explores the usage of nano-biosensors for rapid identification and quantification of foodborne pathogens, such as microorganisms, viruses, and parasites, allowing on-web page pathogen detection and timely interventions to prevent outbreaks. Additionally, the review highlights the tracking of meals satisfactory signs of using nano-biosensors, including freshness, spoilage, and dietary composition. Accurate assessment of those parameters offers treasured information to manage and predict shelf-life. Overall, the advancements in nano-biosensor generation maintain high-quality promise for ensuring the integrity of meals products, defensive public fitness, and assembly regulatory standards

Investigating Strategies for Sustainable Vegetable Food Crop System in Three Agro Ecological Zones of the Humid Tropics Area of Cameroon

Vegetable cultivation remains an essential component of local people’s livelihoods. However, marked trend shifts in the varieties of vegetables due to large-scale commercial vegetable farming of exotic varieties in the broader market economy have resulted in the gradual disappearance of biodiversity involving vital species. The present study examined the situation of vegetable crop farming in three agro-ecological zones of Cameroon. Data were collected from a random sample of 235 respondents (177 farming households and 58 farm input wholesalers) by means of structured questionnaires. Vegetables were observed in both single and mixed cropping systems in all agro-ecological zones. Traditional vegetables such as African nightshade, waterleaf and Fluted pumpkin (okomobong) dominated in the Buea and Ebolowa areas. Over 51% of the vegetable farmers were women, although there was a rising population of men farming particularly in the Bafoussam area. Farmers remarked that pests and diseases followed by lack of good seeds were the main obstacles to vegetable farming. The study therefore points to the need for modification of the microenvironment and changing farming practices. Hence, strategies to fight poverty and malnutrition in Cameroon should include the promotion of traditional leafy and fruit vegetables by providing good quality seeds and variety screening trials

The еffect of season and parity on the reproductive performance of sows

The aim of this study was to analyze the effect of season and number of parity on the reproductive performance of sows kept on a commercial farm. To achieve this objective, 800 nrs productive parent sows and a total of 958 parities were analyzed. The results show that sow’s breeding season had a significant effect on the weaning-to-oestrus interval, the farrowing rate, the litter size and weaning piglets with positive results during autumn, winter and spring seasons. The number of parity has a significant effect on the weaning-to-oestrus interval, litter size and weaning piglets with acceptable values in sows with more farrowing. The results of this study on a pig farm with analysis which highlights the risk factors associated with reproductive performance of sows, could be used to improve sow farm practices