Review of vegetative propagation of cacao (Theobroma cacao L.) by rooted cuttings. 2. Environmental and technical considerations

ABSTRACT The paper reviews the unfavourable environmental factors and technical difficulties that have limited the extensive use of vegetative propagation by rooted cuttings in multiplying cacao. Important among the external factors affecting rooting of cacao cuttings are light, temperature, humidity, and the air-moisture relations of the rooting media. The most important technical factors that affect rooting of cuttings are hormonal treatment, wounding, etiolation, and exogenous supply of carbohydrates and minerals to cuttings. These factors may influence rooting success in isolation or in combination with each other because it is often impossible to separate the effect of one factor from the other. The light intensity at which rooting occurs is dependent on temperature. The relative humidity within the propagation set-up is related to the light intensity and associated temperature. The effects of various media on rooting of cuttings are usually closely influenced by the temperature and water relations. The most effective hormonal treatment for cacao is a mixture of indole butyric acid (IBA) and naphthalene acetic acid (NAA) in equal proportions at a concentration dependent on the dipping time and the size of cutting. Wounding and etiolation are treatments which have been reported to improve rooting in most tree species, but have not had wider application in cacao propagation. Exogenous application of carbohydrates may improve rooting of cuttings. The need is for an effective manipulation of the external environment and a wider exploitation of some technical factors to improve on rooting in cacao. . Cet article fait une révision de facteurs environnementaux favorables et les diffecultés techniques qui ont limité l'utilisation extensive de propagation végétative pour la multiplication de cacao. Inclus dans les facteurs extérieurs importante influençcant l'enracinement de boutures de cacao saont: la lumière, la température, l'humidité et les relations d'air-humidité de substances de la prise de raines. Les facteurs techniques les plus importants qui influencent la prise de racines par les boutures sont le traitement hormonal, la coupe blessante, étiolement et la provision exogène de hydrates de carbone et de minérals. Ces facteurs pourraient influencer le succès de la prise de racines en isolement ou en combinaison l'un evec l'autre comme ce n'est pas souvent possible de séparer l'effet d'un facteur de l'autre. L'intensité de lumière à laquelle la prise de racines se produit dépend de la température. L'humidité relative à l'intérieur de l'instensité de la lumière et à la température associés. Les effets des différents substances sur le plus souvent étroitement influencés par les rapports de température et d'eau. Le traitement hormonal le plus efficace pour le cacao et une mèlange de IBA et NAA à parts égales d'une concentration dépendant de temps d'enfoncement et les dimensions des boutures. La coupe blessante et l'étiolement sont des traitements qui ont été annoncé d'améliorer la prise de racines en plusieurs espèces d'arbre mais qui n'ont pas réalisé de plus grande application de propagation de cacao. L'application exogène de hydrates de carbone pourrait améliorer la prise de racines de semis. Il y a la nécessité d'une manipulation efficace de l'environnement extérieur et une exploitation plus grande de quelques facteurs techniques pour améliorer la prise de racines de cacao. Ghana Journal of Agricultural Science Vol. 39 (2) 2006: pp. 217-22

Review of vegetative propagation of cacao (Theobroma cacao L.) by rooted cuttings. 1. Physiological considerations

The paper reviews physiological factors that affect rooting of cocoa stem cuttings, including clonal differences, leaf area, physiological age, anatomical features, nutritional and biochemical factors which exert the strongest influence. Upper Amazon and Trinitario clones root better than Amelonado clones, the causes of the differences being mainly nutritional. Rooting does not normally occur in cuttings without leaves, because they are deprived of their photosynthetic function. Rooting decreases in general with increasing age of the tree. Cuttings from trees in healthy and luxuriant vegetative growth are, therefore, preferable. No major differences are observed in rooting between orthotropic and plagiotropic cuttings of cocoa. Information on the anatomical condition of cuttings in rooting performance is limited. However, a clear relationship is noted between the position of cutting on the stock plant and rooting performance; rooting potential increases from the apex to the base of the shoot. Single-node cuttings take longer time to root than multinode cuttings. The physiological condition of cacao cuttings changes with changing seasons, and this in turn affects their rooting performance. Cacao shoot is in optimal condition for rooting immediately after the flush has matured. The interaction of two or more physiological factors determines the degree of success in rooting .Cet article fait une révision de facteurs physiologiques qui influencent la prise de racines des boutures de tige de cacao. Parmi les facteurs physiologiques influençant la propagation de cacao par les boutures de cacao, les différences du clonage, la surface foliaire, l'âge physiologique, les traits anatomiques, les facteurs nutritionnels et biochimiques exercent la plus forte influence. Les clones d'Upper Amazon et de Trinitario prennent les racines mieux que les clones d'Amelonado, les causes des différances étant nutritionnelles. Généralement la prise de racine ne se produit pas dans les boutures de tige privées de leur feuilles, les fonctions de la feuille pendant la prise de racines étant photosynthétiques implicites. La facilité de la prise de racine des boutures de cacao deminue en générale avec l'augmentation de l'âge de l'arbre. Les boutures des arbres en croissance végétative de bonne santé et luxuraint sont donc préférables. Il semble qu'il n'y a pas de différences majeures dans la prise de racines entre les boutures de cacao d'orthotropie et de plagiotropie. L'information sur la condition anatomique des boutures de cacao par rapport au résultat de la prise de racines est limitée dans la litérature. Toutefois il y a un rapport certain entre la position de la coupe sur le tronc de plante et le résultat de la prise de racine; avec le potentiel de la prise de racine augmentant du sommet au pied du tronc. Les boutures d'un seul nœud prennent de plus longue temps pour prendre les racines que les boutures de multinœud. La condition physiologique de boutures de cacao change avec le changement des saisons et ceci influence également leur résultat de la prise de racines. La pousse de cacao est en condition optimale pour la prise de racines sotôt après l'affleurement est mûr. L'interaction de deux ou plus des différents facteurs physiologiques détermine le degré de succès réalisé dans la prise de racine de boutures de cacao sous les différentes conditions de propagation. Ghana Journal of Agricultural Science Vol. 39 (2) 2006: pp. 209-21

Optimisation of Operational Parameters of a Spiral Classifier Using Design of Experiment (DOE)

Abstract Classifying Mn Ore to improve upon the grade and the properties has become a crucial activity for the Mn industry since it increases the market value of the ore. Ghana Manganese Company (GMC) has renovated their oxide washing plant by integrating it with a spiral classifier to make a batch system operating process. Particle size of <3.35mm (Mn grade of 43-47%) obtained from the primary section of the plant served as feed to the classifier and with the plant condition (i.e. at 60 min washing time, 30 rev/min speed of spirals and feed tonnage of 6 t), Mn grade of 49% was achieved. This paper focused on the optimisation of some selected operational parameters of the classifier to obtain a Mn grade >50% using Design of Experiment (DOE). Series of test works were designed using the DOE for the classifier using the constraints of washing time (30-90 min), speed of spirals (20-40 rev/min) and feed tonnage (6-9 t). The outcome of the test work after simulation showed that all the selected parameters had a great influence on Mn grade. The spiral speed and feed tonnage correlated negatively to the Mn grade with washing time correlating positively. Operating the spiral classifier at a feed rate, spiral speed and washing time of 6 t, 25 rev/min, and 30 min, respectively, yielded Mn grade of 53%. A Confirmatory test using the established conditions gave a Mn grade of 53%, which is a 4% increment in the previous Mn grade which was 47%. The outcome of the studies is the new established operational conditions which is adhered to by the plant, producing a manganese concentrate grade ranging between 52-54%.   Keywords: Design of Experiment (DOE), Spiral Classifier, Grade, Manganes

Appraisal of some methods of weed control during initial establishment of cocoa in a semi-deciduous forest zone of Ghana

In appraising the effects of the quantum and quality of weed control required in establishment of young cocoa, six manual methods of controlling weeds were compared with chemical weed control at two stations of the Cocoa Research Institute of Ghana. Growth of cocoa seedlings after 2 years in the field was superior (P < 0.05) in plots which were clean-weeded two or four times per year or treated with paraquat four times per year than when plots were slashed two or four times per year. There was strong evidence to suggest that treatments which ensured a weed-free environment to the cocoa over a long period were favourable to girth increments in the seedlings. Death of seedlings during establishment was generally lower in plots which were either clean-weeded or treated with paraquat. Labour requirement for controlling weeds with paraquat was considerably lower than that required for the other treatments. Considering the equipment and chemical input, paraquat application was expensive compared to high slashing with or without clean-line weeding two times a year, or clean weeding two times a year; but by virtue of its efficacy, it is recommended for cocoa establishment. En évaluant les effets du quatum et de la qualité de désherbage exigé dans la culture de jeune cacao, six méthodes de désherbage manuel étaient comparées avec le désherbage chimique à deux stations de l'Institut de Recherche en cacao du Ghana. La croissance de semis de cacao, après deux années, dans le champ était supérieure (P £ 0.05 ) dans les lots qui étaient complètement désherbés 2 ou 4 fois/an ou traités avec le paraquat 4 fois/an que dans les lots qui étaient entaillés 2 ou 4 fois/an. Il y avait de nombreuses preuves qui laissent penser que les traitements qui assuraient un environnement sans mauvaise herbe pour le cacao sur une longue période étaient favorables aux augmentations de circonférence des semis. La mort de semis pendant la culture était dans l'ensemble plus faible dans les lots, qui étaient soit complètement désherbés soit traités avec le paraquat. L'exigence de main-d'oeuvre pour maîtriser les mauvaises herbes avec le paraquat était considérablement plus faible que celle exigée pour les autres traitements. En ce qui concerne les matériels et les intrants chimiques, l'application de paraquat était chère que les entailles élevées avec ou sans le désherbage complet en ligne deux fois par an ou le désherbage complet deux fois par an mais en vertu de son efficacité il est recommandé pour la culture de cacao. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 67-7

CONSUMER PREFERENCES AND PURCHASE INTENTIONS FOR RATTAN FURNITURE

Although research on consumer preference and purchase intentions has received significant attention, little research has been performed with respect to furniture products, particularly in the area of empirical hypothesis testing. This study used regression models to test hypotheses relating to positional goods consumption and environmental and sustainable consumption theories to investigate consumers’ preference for rattan cane furniture and their intentions to purchase the product. A questionnaire was administered to 750 staff and students from universities, polytechnics, and research institutions in Ghana. The results showed that social status, modernity, and environmental safety supported the preference and purchase intentions for rattan cane furniture, whereas mixed results emerged from sustainable consumption. The most important driver of preference for rattan cane furniture was modernity, followed byenvironmental safety, social status, and sustainable consumption. In the case of purchase intentions, social status emerged as the most important factor, followed by modernity, and then environmental consumption. Building a positive social, environmental, and sustainable image of rattan cane furniture will enhance the product’s value, and this will culminate in increasing consumers’ preference for the product and their intentions to purchase the product. The study concluded that through market segmentation, manufacturers, and marketers of rattan cane furniture can target consumers who are proenvironmentalists and those who want to use the product to enhance their social image, thereby attracting a price premium

Effect of Formaldehyde Treatment on Bacteria-Infected Hatching Eggs of Gallus gallus domesticus Linnaeus, 1758

The effectiveness of formaldehyde egg disinfection is well documented in literature despite its reported toxicity. This study focused on the need for an optimum formaldehyde concentration (FC) that significantly reduces microbial load with minimal damaging effect on egg viability and hatchability. Using a true experimental design, bacterial load on formaldehyde-treated (FT) and control groups of eggs and hatchability were compared. Gram-staining and biochemical tests identified five bacterial species: Escherichia coli, Enterobacter sp., Bacillus cereus, Staphylococcus aureus and Micrococcus sp. with the two coliform bacteria, E. coli and Enterobacter sp., dominating. Comparison of median differences of bacterial load on eggs before and after formaldehyde treatment by Wilcoxon Signed-Rank Test showed marginal significance in bacterial load reduction (Z = -2.016, P = 0.044). This difference was observed for bacterial load between the control group (CG) and the FT group with FC 30/20 ml/g (U = 3.0, P = 0.047). The hatchability of the CG differed significantly from four FT groups of eggs with FC 30/20 ml/g showing the highest level of significance [χ² (1) = 14.71; P = 0.0001]. A FC of 30/20 ml/g produced the best domestic fowl egg disinfection compared to other FCs and hatchability decreased with increasing formalin volume

Online shopping experiences: A quantitative investigation into hedonic value, trust, and risk in the South African retail industry

The purpose of this quantitative study is to investigate the experiences of online shoppers as regards hedonic value, trust, and risk associated with their online shopping. Furthermore, the study sought to investigate whether the respondents of different gender, age, education, and income have different online shopping experience (hedonic value, trust, and risk). Data was collected through an online survey in South Africa of consumers who has shopped online from 2019 to 2020. A total of 164 usable questionnaires were included in the final quantitative data analysis. The results of the study show that online shopping provides a promising avenue for consumers to find the latest products and services. However, the overall hedonic experience was inadequate in providing dimensions such as escape, learning experience, adventure-seeking, and fun activities. Considerable effort is essential to win the trust of online shoppers in South Africa. The ability to judge product quality and compare its quality emerged as a concerning risk factor to customers. The experience of hedonic value for male online shoppers was slightly lower than for females. Significant differences were found between the income and hedonic value of online shoppers. Based on these findings, recommendations were offered that will hopefully enhance online shopping

Effects of ascorbic acid, salt, lemon juice, and honey on drying kinetics and sensory characteristic of dried mango

The effects of ascorbic acid, salt solution, lemon juice, and honey pretreatment on the drying kinetics and sensory characteristics were studied. Pretreatments used affected the effective moisture diffusivity and rehydration properties of the dried mangoes. The effective moisture diffusivity values were 2.22 × 10-10 m2/s for ascorbic acid, 1.80 × 10-10 m2/s for salt solution, 2.01 × 10-10 m2/s for lemon juice, 1.93 × 10-10 m2/s for honey pretreated mangoes, and 2.31 × 10-10 m2/s for the control slices. Pretreatments enhanced the drying rate potential of mangoes. Among the thin-layer drying models fitted to the experimental data, the Middil model gave the best fit. The ascorbic acid pretreated samples were the best while the salt solution ones were the poorest with respect to reconstitution capacity. Consumer studies for overall preference for taste, colour, texture, flavour and chewiness of the dried products revealed that there was a higher preference for honey pretreated dried samples followed by the ascorbic acid, control, lemon juice, and salt solution pretreated samples. The results demonstrate that these pretreatments can be applied to enhance the moisture transport during drying and the quality of the dried products

Editorial: Sustainable Waste Management Innovations: Developing New Ventures for Improved Health and Environmental Wellbeing

In this Editorial, we synthesise the articles in the Special Issue with unique insights into sustainable waste management innovations and sustainable business practices [...

Connecting DNA Origami Structures Using the Biotin-Streptavidin Specific Binding

This work made use of the strong interaction between biotin and streptavidin to connect designed DNA origami structures. The caDNAno software was used to design a 6 layer 3D origami cross-like structure. Selected DNA strands at the engineered attachment sites on the DNA origami structure were biotinylated. After folding of the origami structures, the biotinylated strands stick out of the attachment sites. Purified samples of origami structures were then mixed with streptavidin and the mixture purified. After characterization, we see that attachment only occurs at the biotinylated sites. Agarose gel electrophoresis, UV-vis spectroscopy and TEM were used to characterize the structure.Key words: DNA Origami, Interaction, Biotin-Streptavidin, Nanomaterials, TEMAbbreviation: EDTA, Ethylenediaminetetraacetic acid; TEM, Transmission electron microscop