The purpose of the study was to present descriptive data bout the industry, determine the importance of the competencies needed for job entry, and assess the manpower needs of the ornamental horticulture industry in Utah. The identified population of 576 ornamental horticulture enterprises was categorized into seven areas of specialization: Arborists (4.5%), Maintenance of Landscapes (10.8%), Landscape Construction (18.6%), Golf Courses (13.5%), Greenhouse Production (5.4%), Florist-Plant Shops (30.9%) and Garden Center-Nurseries (16.3%). The data were collected by a survey-questionnaire. One hundred and sixteen ornamental horticulture enterprises responded to the survey. This amounted to 38% of the industry sampled and 20% of the population. Findings of the study indicated that single enterprises conduct work in a number of the areas of specialization. Ninety-two of the ninety-four competencies were rated at least of some importance to entry level workers. The most important competencies common to all the areas of specialization were: Human relations and communications, pest identification and control, record keeping, and safety. Other highly rated individual competencies in the major areas of specialization included: 1) Arborists--mix and handle chemicals safely, turf establishment and maintenance, removal of trees and shrubs, and pruning techniques; 2) Maintenance of Landscapes--mix and handle chemicals safely, apply fertilizer materials, operate and maintain spray equipment, maintain turf and operate and service automatic systems; 3) Landscape Construction--plant and transplant, turf establishment and maintenance and sell products and services; 4) Golf Courses-apply fertilizer materials, maintain golf greens and turf and apply knowledge of irrigation and watering methods; 5) Greenhouse Production-apply knowledge of irrigation and water ing methods; sell products and services, and operate a cash register and handle money; 6) Florist-Plant Shops--design and construct floral pieces, dish gardens, and terrariums, operate a cash register and handle money and design displays; 7) Garden Center Nurseries--operate a cash register and handle money, sell products and services, and select plant materials according to growth habits and uses. The number of employees anticipated in the future is growing at a 16% yearly rate. The greatest anticipated yearly expansion of full time employees in the areas of Landscape Construction (63%), Arboriculture (35%) and Greenhouse Production (32%). Members of owners' families comprise 17% of the industry's employees. The study also indicated a preference for workers presenting specific job competencies at job entry.

Many plants require exposure to low temperature for a certain period during each year. This was determined more than a century ago. Understanding this phenomenon, known as the rest period, is part of a larger problem of understanding the factors which determine the ability of an organism to grow. The property of rest is ultimately a property of the actively growing cells, rather than that of the cells involved with protection and support.

Thesis (M.Sc.) --University of Limpopo, Turfloop Campus, 2010 / A study was conducted to determine the effect of fermentation temperature and duration on chemical composition of bush tea (Athrixia phylicoides DC.). Bush tea was fermented in incubators at different temperatures and for different lengths of time for quality improvement. Treatments for fermentation temperature consisted of control (24°C; room temperature), 30°C, 34°C, 38°C and 42°C where the tea leaves were fermented for 30 minutes. Treatments for fermentation time consisted of control (0), 60, 90, and 120 minutes at an incubator temperature of 22-26°C. A completely randomized design (CRD) was used with three replicates for both evaluations. The chemical analysis (polyphenols, tannins and antioxidants) were done using Waterman and Mole (1994) method. The results of this study demonstrated that fermentation temperature significantly increases polyphenols at 30, 34, and 38°C whereas tannin content showed a great reduction at 38 and 42°C. Increasing fermentation time achieved a significant increase in both polyphenols (60 and 90 minutes) and tannin contents (90 and 120 minutes). However, changes in either fermentation temperature or time did not give any significant influence on antioxidant content of bush tea. / National Research Foundation

Thesis (M.Sc)--University of Limpopo, 2010. / Black tea (Camellia sinensis) and black tea combined with bush tea (Athrixia phylicoides) were analyzed for their polyphenol content, antioxidant activity and tannin content. Solvent extraction methods were used for extracting polyphenols, antioxidant activity and tannin content. Total phenols were determined using the Folin-Ciocalteu method, antioxidant activity using Trolox Equivalent Antioxidant Capacity (TEAC) assay and tannin content using vanillin-HCl method. Polyphenol content, antioxidant activity and tannin content were calculated using regression equation Y=MX+C, where C=intercept, Y= Absorbance of the sample and M= Gradient. Results of black tea in this study showed that total polyphenols, antioxidant activity and tannin content decreased with decrease in temperature and time and this was attributed to the release of polysaccharides at 90°C. At 90°C for 3 minutes 7.68mg/100g of total polyphenol, 3.85μmol/g of antioxidants and 2.81mg/100g of tannin were obtained and this amount decreased to 5.50mg/100mg for total polyphenols, 1.31μmol/g for antioxidant activity and 0.72mg/100mg for tannin content at 30°C for 10 minutes. Combining the two tea types (50:50) resulted in a significant (p<0.005) decrease in total polyphenols, antioxidant and tannin content. Results of this study showed that at high temperature of 90°C for 3 minutes 2.64mg/100g for total polyphenol, 2.48μmol/g for antioxidants and 1.8mg/100g for tannin were obtained and these amounts decreased to 1.39mg/100mg for total polyphenols, 0.35μmol/g for antioxidant activity and 0.64mg/100mg for tannin content at 30°C for 10 minutes. Thus high brewing temperature causes increase in total polyphenols, antioxidant activity and tannin content of the combined teas. This study showed that black tea and combined black tea and bush tea solutions had large TEAC radical scavenging activity which can be related to total polyphenols and catechins. The antioxidant activity of the tea solution increased with increase in extraction temperature and duration of soaking. It is recommended that 3-min soaking temperature of 90 °C of black tea and combined bush tea and black tea can be used due to the highest total polyphenols and antioxidant activity obtained.

Thesis(M.Sc)--University of Limpopo, 2010. / Bush tea (Athrixia phylicoides DC.) has received interest as another indigenous South African herbal tea with potential for commercialization. The success of commercialization of bush tea hinges on maintenance or enhancement of quality of bush tea as a herbal beverage. Herbal tea quality is one of the critical factors in commercialization that would determine the price of tea for local sale and export. A research was conducted to determine chemical profiles of bush tea at different phenological stages and as influenced by pruning and application of growth regulators. A trial to determine the quality of tea harvested at various phenological stages (namely new growth, older growth and whole plants) from wild and cultivated bush tea was conducted. This was to help determine the best phenological stage to harvest bush tea of best quality. In cultivated bush tea, harvested new growth or as whole plants proved to be of higher quality owing to their higher polyphenol and tannin attributes respectively. In wild bush tea, both new and older growth proved to be of good quality owing to the higher total polyphenol content and higher total antioxidants, respectively. A trial to determine the effect of pruning at different heights on growth and quality of bush tea was also conducted. Pruning of bush tea largely led to yield reduction. Unpruned tea plants remained the tallest plants, with higher number of branches, bigger leaf area and a larger biomass than apically, middle and base pruned bush tea plants. Pruning at different heights also proved to have little or no effect on quality of bush tea. While only total polyphenols remained higher in unpruned tea plants, no significant differences were observed in tannin and total antioxidant content in unpruned, apically, middle and base pruned tea plants. A third trial was conducted to investigate the effects of gibberellins on sprouting and quality of bush tea. The trial results showed that gibberellin application had a iv favourable effect on growth of bush tea, with application of 3% and 4% yielding the highest growth. The results also indicated a declining total polyphenol and antioxidant content with increasing gibberellin application rate, while tannins peaked at 2% application rate.

Thesis (M.A.) (Language translation) --University of Limpopo, 2007. / See document, page 135. / N/A

The results of the 3-year project successfully indicated that petroleum-derived spray oils can be used for effective control of a range of citrus pests including citrus leafminer, Asiatic citrus psyllid, chaff scale, red scale, citrus red mite. The results suggested that it should be possible, through use of horticultural and agricultural mineral oils and enhanced natural enemy activity, to reduce the number of pesticide sprays applied annually in China from 14-16 sprays to significantly fewer sprays in most regions. The results are also valuable as references for the implementation of citrus integrated pest management programs in Australia and other citrus-growing countries. However, despite extensive use of PDSOs in citrus and other crops since the late 1800s, few studies have been undertaken to determine their disruptive effects on orchard ecosystems or to compare their effects with those of synthetic pesticides, and these studies are limited in their sc / Doctor of Philosophy (PhD)

New Zealand�s main export earnings come from the primary production area including agriculture, horticulture, and viticulture. One of the major contributors in this area of horticulture is the production of quality export grade fruit; specifically apples. In order to maintain a competitive advantage, the systems and methods used to grow the fruit are constantly being refined and are increasingly based on data collected and analysed by both the orchardist who grows the produce and also researchers who refine the methods used to determine high levels of fruit quality. To support the task of data analysis and the resulting decision-making process it requires efficient and reliable tools. This thesis attempts to address this issue by applying the techniques of Connectionist-Based Intelligent Information Systems (CBIIS) for Image Analysis and Knowledge Discovery. Using advanced neurocomputing techniques and a novel knowledge engineering methodology, this thesis attempts to seek some solutions to a set of specific problems that exist within the horticultural domain. In particular it describes a methodology based on previous research into neuro-fuzzy systems for knowledge acquisition, manipulation, and extraction and furthers this area by introducing a novel and innovative knowledge-based architecture for knowledge-discovery using an on-line/real-time incremental learning system based on the Evolving Connectionist System (ECOS) paradigm known as the Evolving Fuzzy Neural Network (EFuNN). The emphases of this work highlights knowledge discovery from these data sets using a novel rule insertion and rule extraction method. The advantage of this method is that it can operate on data sets of limited sizes. This method can be used to validate the results produced by the EFuNN and also allow for greater insight into what aspects of the collected data contribute to the development of high quality produce.

Doctor of Philosophy (PhD) / The Flesh Browning (FB) disorder of ‘Cripps Pink’ apples presents a significant threat to the established market identity of the ‘Cripps Pink’ apple in Australian and export markets. Climatic conditions during fruit growth and development predispose ‘Cripps Pink’ apples to developing the FB disorder during storage. The FB disorder can be classified into two distinct disorders based on their physiological and structural differences and by seasonal climatic conditions. The diffuse type of FB (DFB) is a chilling injury, occurring in districts or seasons accumulating less than 1100 growing degree days (GDD) above 10oC between full bloom and harvest. In these climatic conditions, ‘Cripps Pink’ apples have delayed postharvest ethylene production. Diffuse FB effects fruit cortex tissue and is characterised as cellular collapse. Storing fruit at 3oC can reduce the incidence of DFB. The radial type of FB (RFB) is primarily a senescent disorder, occurring in districts or seasons accumulating greater than 1400 GDD above 10oC between full bloom and harvest. In these climatic conditions, postharvest ethylene production is not delayed. Radial FB affects the cells adjacent to the vascular tissue of the fruit and is characterised by damaged cell walls. Storing fruit at 1oC can reduce the incidence of RFB. Harvest maturity and the level of CO2 in the storage atmosphere are additive influences on the development of RFB. Seasons or districts accumulating more than 1700 GDD have a very low risk for developing RFB. Seasonal climatic conditions can provide a guide for predicting the risk of developing RFB and DFB during storage.

Peut être plus encore que dans d'autres secteurs de production végétale, en horticulture les contraintes économiques imposent une technicité croissante. L'artificialisation des productions de plants de fraisiers a commencé depuis longtemps. L'empirisme a permis de mettre au point des pratiques qui ont longtemps suffi. Mais, cette artificialisation demande de plus en plus une maîtrise raisonnée qui doit reposer sur des connaissances précises de l'écophysiologie des plants. D'autre part, des recherches ont permis de définir un test de capacité de croissance des bourgeons, inspiré de ceux faits sur les bourgeons des arbres, et nous l'avons mis en oeuvre comme référence. Cependant, en particulier au niveau de l'intérêt pour les professionnels, ce test implique des méthodes encore trop lourdes. D'autres marqueurs plus faciles à mesurer semblaient des candidats valables, mais seules des études préliminaires ont été faites.C'est le cas du flux de chaleur métabolique (Q) et du flux de respiration (RCO2) que nous avons testé en mesure immédiate et après acclimatation des plants à 20°C. Nos résultats indiquent que Q et RCO2 en mesure immédiate ne peuvent constituer de bons marqueurs de capacité de croissance, car leurs valeurs sont fortement corrélées aux températures moyennes subies par les plants dans les quelques jours précédant la mesure. En revanche, le différentiel obtenu entre mesure immédiate et mesure réalisée après acclimatation pendant 48 h à 20° C est potentiellement un marqueur intéressant, d'obtention beaucuop plus rapide que les résultats des tests classiques. Il faudra cependant optimiser les conditions de réalisation de l'acclimatation et des mesures microcalorimétriques et augmenter sensiblement le nombre de répétitions des mesures. L'utilisation du paramètre humidité pondérale, dont la dynamique d'évolution est très proche de celles de Q et RCO2, comme substitutif à ces paramètres peut constituer un autre outil intéressant les producteurs de plants