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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Feasibility of Whole-plant Corn Logistics for Biobased Industries

Khanal, Asmita 10 August 2022 (has links)
No description available.
52

Evaluation of Harvest Aid Systems in Mid-South Soybean (Glycine max) Production

Thomason, Blake William 11 December 2015 (has links)
Research was conducted in 2014 to evaluate the efficacy of harvest-aid systems and the performance of harvest aids applied at various timings in Mid-South soybean production. Evaluations included yield, desiccation, green stems and pods, and seed quality. Saflufenacil did not perform as well as the producer standard 14 DAT at the Starkville, MS location with desiccation levels of 78 and 98%, respectively. However, similar performance was observed 14 DAT at the Brooksville, MS location. When applied at R6.5, paraquat based treatments improved desiccation and reduced green stem 7 DAT compared to other treatments. No yield differences were observed between harvest aid treatments. However, yield differences were observed between the R6.0 and R6.5 timings. These data suggest saflufenacil is an effective harvest aid option, but may require up to 14 days for optimum desiccation. In addition, yield is not impacted by harvest aid product, but rather the timing of the application.
53

Design of an Algae Harvesting Cable Robot, Including a Novel Solution to the Forward Pose Kinematics Problem

Needler, Noah J. 25 September 2013 (has links)
No description available.
54

Factors influencing visitor loyalty at an agri-festival in South Africa / Monique Fourie

Fourie, Monique January 2014 (has links)
The agri-tourism sector is an important sector, especially in South Africa, since there are rural areas that can still be developed for these purposes. Agri-tourism can be achieved when both the agricultural and tourism sector work together in achieving an entrepreneurial advantage. Some of the benefits of agri-tourism include job creation, new ideas and innovation, it serves as additional income and it has an educational aspect attached to it. Agri-tourism is a form of rural tourism and agri-festivals such as the NAMPO Harvest Day is part of the numerous categories of agri-tourism. The NAMPO Harvest Day is the largest agri-festival in the Southern Hemisphere which attracted over 72 000 visitors in 2013. The NAMPO Harvest Day started in the Bloemfontein district in 1967 and continued its success in Bothaville, Free State. To ensure that a decrease in ticket sales and attendance of the agri-festival does not take place or a decrease in the product life cycle of the agri-festival, it is important for the management team to focus on the factors that may have an influence on loyalty such as image and customer satisfaction, visitor attributes, behavioural intentions, festival attributes and travel motives. Competition is increasing in South Africa, which means that the management must have a distinct advantage over the other agri-festivals hosted in South Africa. Loyalty occurs when a customer repeatedly invests in a product or service where the result will be positive word of mouth and positive recommendations to others. Seeing that the NAMPO Harvest Day is the largest of its kind in the Southern Hemisphere that also attracts international visitors, it is important for management to focus on the loyalty factors to ensure continuous success. The goal of this study was to thus assess the factors that influence visitor loyalty to this agri-festival in South Africa. In order to achieve this goal, a survey was conducted at the NAMPO Harvest Day in 2014. A total of 422 questionnaires were administered over a period of 4 days. Various statistical analyses were performed: descriptive statistics were used to profile the respondents where after factor analyses were used to firstly identify the factor Loyalty and secondly to identify the factors that may influence loyalty to the festival. Nine factors were identified (in order of importance): Agricultural exposure and edification, General management, escape and socialisation, Price and quality of implements, machinery and livestock, Price and quality of food and beverages, Amenities, Signage and marketing, Networking and trade, and Value. T-tests, ANOVAs and Spearman’s Rank Order Correlations were used to determine whether statistically significant differences existed between the respondents’ socio-demographic and behavioural characteristics and the factor Loyalty as well as between the contributing factors, so as to establish where differences occur between two groups and more groups. There were statistically significant differences based on demographic and behavioural intentions and loyalty factors. Spearman’s Rank Order Correlations were used to determine which demographic and behavioural aspects correlate with one another. In addition, Structural Equation Modelling was used to determine the relation between the factors and Loyalty. In preparation for the Structural Equation Modelling, Spearman’s Rank Order Correlations were also used to determine the relation between the factor Loyalty and the contributing factors as well as between the different contributing factors. The model provided evidence of a good fit since the CFI was between 0.0 and 1.0 (0.819) and the relative/normed chi-square was 3.987 and acceptable chi-square ranges between 2.0 and 5.0. The factors that had a direct relationship and are supported at 5% significance level with Loyalty were Agricultural exposure and edification as well as Lifestyle, escape and socialisation. The contribution of this research is twofold: firstly, to the authors’ knowledge, agri-tourists to a specific agri-festival in South Africa were analysed in terms of their demographic profile and behavioural characteristics. Therefore this research greatly contributes towards the literature base regarding these types of tourists. Secondly, this research identified the factors that contribute towards loyalty at an agri-festival and how organisers and marketers can effectively use these factors to sustain loyalty among not only repeat visitors, but first-timers as well. The results from this research can aid this agri-festival to remain competitive and remain in a growth phase of its product lifecycle. This is imperative for the future success of agri-festivals such as the NAMPO Harvest Day. / MA (Tourism Management), North-West University, Potchefstroom Campus, 2015
55

Factors influencing visitor loyalty at an agri-festival in South Africa / Monique Fourie

Fourie, Monique January 2014 (has links)
The agri-tourism sector is an important sector, especially in South Africa, since there are rural areas that can still be developed for these purposes. Agri-tourism can be achieved when both the agricultural and tourism sector work together in achieving an entrepreneurial advantage. Some of the benefits of agri-tourism include job creation, new ideas and innovation, it serves as additional income and it has an educational aspect attached to it. Agri-tourism is a form of rural tourism and agri-festivals such as the NAMPO Harvest Day is part of the numerous categories of agri-tourism. The NAMPO Harvest Day is the largest agri-festival in the Southern Hemisphere which attracted over 72 000 visitors in 2013. The NAMPO Harvest Day started in the Bloemfontein district in 1967 and continued its success in Bothaville, Free State. To ensure that a decrease in ticket sales and attendance of the agri-festival does not take place or a decrease in the product life cycle of the agri-festival, it is important for the management team to focus on the factors that may have an influence on loyalty such as image and customer satisfaction, visitor attributes, behavioural intentions, festival attributes and travel motives. Competition is increasing in South Africa, which means that the management must have a distinct advantage over the other agri-festivals hosted in South Africa. Loyalty occurs when a customer repeatedly invests in a product or service where the result will be positive word of mouth and positive recommendations to others. Seeing that the NAMPO Harvest Day is the largest of its kind in the Southern Hemisphere that also attracts international visitors, it is important for management to focus on the loyalty factors to ensure continuous success. The goal of this study was to thus assess the factors that influence visitor loyalty to this agri-festival in South Africa. In order to achieve this goal, a survey was conducted at the NAMPO Harvest Day in 2014. A total of 422 questionnaires were administered over a period of 4 days. Various statistical analyses were performed: descriptive statistics were used to profile the respondents where after factor analyses were used to firstly identify the factor Loyalty and secondly to identify the factors that may influence loyalty to the festival. Nine factors were identified (in order of importance): Agricultural exposure and edification, General management, escape and socialisation, Price and quality of implements, machinery and livestock, Price and quality of food and beverages, Amenities, Signage and marketing, Networking and trade, and Value. T-tests, ANOVAs and Spearman’s Rank Order Correlations were used to determine whether statistically significant differences existed between the respondents’ socio-demographic and behavioural characteristics and the factor Loyalty as well as between the contributing factors, so as to establish where differences occur between two groups and more groups. There were statistically significant differences based on demographic and behavioural intentions and loyalty factors. Spearman’s Rank Order Correlations were used to determine which demographic and behavioural aspects correlate with one another. In addition, Structural Equation Modelling was used to determine the relation between the factors and Loyalty. In preparation for the Structural Equation Modelling, Spearman’s Rank Order Correlations were also used to determine the relation between the factor Loyalty and the contributing factors as well as between the different contributing factors. The model provided evidence of a good fit since the CFI was between 0.0 and 1.0 (0.819) and the relative/normed chi-square was 3.987 and acceptable chi-square ranges between 2.0 and 5.0. The factors that had a direct relationship and are supported at 5% significance level with Loyalty were Agricultural exposure and edification as well as Lifestyle, escape and socialisation. The contribution of this research is twofold: firstly, to the authors’ knowledge, agri-tourists to a specific agri-festival in South Africa were analysed in terms of their demographic profile and behavioural characteristics. Therefore this research greatly contributes towards the literature base regarding these types of tourists. Secondly, this research identified the factors that contribute towards loyalty at an agri-festival and how organisers and marketers can effectively use these factors to sustain loyalty among not only repeat visitors, but first-timers as well. The results from this research can aid this agri-festival to remain competitive and remain in a growth phase of its product lifecycle. This is imperative for the future success of agri-festivals such as the NAMPO Harvest Day. / MA (Tourism Management), North-West University, Potchefstroom Campus, 2015
56

Resistance to airflow and moisture loss of table grapes inside multi-scale packaging

Ngcobo, Mduduzi Elijah Khulekani 03 1900 (has links)
Thesis (PhD(Agric))--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Postharvest quality of fresh table grapes is usually preserved through cooling using cold air. However, cooling efficiencies are affected by the multi-scale packaging that is commercially used for handling grapes after harvest. There is usually spatial temperature variability of grapes that often results in undesirable quality variations during postharvest handling and marketing. This heterogeneity of grape berry temperature inside multi-packages is largely due to uneven cold airflow patterns that are caused by airflow resistance through multi-package components. The aims of this study were therefore to conduct an in-depth experimental investigation of the contribution of grape multi-packaging components to total airflow resistance, cooling rates and patterns of grapes inside the different commercially used multi-packages, and to assess the effects of these multi-packages on table grape postharvest quality attributes. A comprehensive study of moisture loss from grapes during postharvest storage and handling, as well as a preliminary investigation of the applicability of computational fluid dynamics (CFD) modeling in predicting the transport phenomena of heat and mass transfer of grapes during cooling and cold storage in multi-packages were included in this study. Total pressure drop through different table grapes packages were measured and the percentage contribution of each package component and the fruit bulk were determined. The liner films contributed significantly to total pressure drop for all the package combinations studied, ranging from 40.33±1.15% for micro-perforated liner film to 83.34±2.13 % for non-perforated liner film. The total pressure drop through the grape bulk (1.40±0.01 % to 9.41±1.23 %) was the least compared to the different packaging combinations with different levels of liner perforation. The cooling rates of grapes in the 4.5 kg multi-packaging were significantly (P<0.05) slower than that of grapes in 5 kg punnet multi-packaging, where the 4.5 kg box resulted in a seven-eighths cooling time of 30.30-46.14% and 12.69-25.00% more than that of open-top and clamshell punnet multi-packages, respectively. After 35 days in cold storage at -0.5°C, grape bunches in the 5 kg punnet box combination (open-top and clamshell) had weight loss of 2.01 – 3.12%, while the bunches in the 4.5 kg box combination had only 1.08% weight loss. During the investigation of the effect of different carton liners on the cooling rate and quality attributes of ‘Regal seedless’ table grapes in cold storage, the non-perforated liner films maintained relative humidity (RH) close to 100 %. This high humidity inside non-perforated liner films resulted in delayed loss of stem quality but significantly (P ≤ 0.05) increased the incidence of SO2 injury and berry drop during storage compared to perforated liners. The perforated liners improved fruit cooling rates but significantly (P ≤ 0.05) reduced RH. The low RH in perforated liners also resulted in an increase in stem dehydration and browning compared to non-perforated liners. The moisture loss rate from grapes packed in non-perforated liner films was significantly (P<0.05) lower compared to the moisture loss rate from grapes packed in perforated liner films (120 x 2 mm and 36 x 4 mm). The effective moisture diffusivity values for stem parts packed in non-perforated liner films were lower than the values obtained for stem parts stored without packaging liners, and varied from 5.06x10-14 to 1.05x10-13 m2s-1. The dehydration rate of stem parts was inversely proportional to the size (diameter) of the stem parts. Dehydration rate of stems exposed (without liners) to circulating cold air was significantly (P<0.05) higher than the dehydration rates of stems packed in non-perforated liner film. Empirical models were successfully applied to describe the dehydration kinetics of the different parts of the stem. The potential of cold storage humidification in reducing grape stem dehydration was investigated. Humidification delayed and reduced the rate of stem dehydration and browning; however, it increased SO2 injury incidence on table grape bunches and caused wetting of the packages. The flow phenomenon during cooling and handling of packed table grapes was also studied using a computational fluid dynamic (CFD) model and validated using experimental results. There was good agreement between measured and predicted results. The result demonstrated clearly the applicability of CFD models to determine optimum table grape packaging and cooling procedures. / AFRIKAANSE OPSOMMING: Naoes kwaliteit van vars tafeldruiwe word gewoonlik behou deur middel van verkoeling van die produk met koue lug. Ongelukkig word die effektiwiteit van dié verkoeling beïnvloed deur die multivlakverpakking wat kommersieel gebruik word vir die naoes hantering van druiwe. Daar is gewoonlik ruimtelike variasie in die temperatuur van die druiwe wat ongewenste variasie in die kwaliteit van die druiwe veroorsaak tydens naoes hantering en bemarking. Die heterogene druiwetemperature binne die multivlakverpakkings word grootliks veroorsaak deur onegalige lugvloeipatrone van die koue lug as gevolg van die weerstand wat die verskillende komponente van die multivlakverpakkings teen lugvloei bied. Die doel van hierdie studie was dus om ‘n indiepte eksperimentele ondersoek te doen om die bydrae van multivlakverpakking op totale lugvloeiweerstand, verkoelingstempo’s en –patrone van druiwe binne kommersieël gebruikte multivlakverpakkings te ondersoek, asook die effek van die multivalkverpakking op die naoes kwaliteit van druiwe te bepaal. ‘n Omvattende studie van vogverlies van druiwe tydens naoes opberging en hantering, asook ‘n voorlopige ondersoek na die bruikbaarheid van ‘n berekende vloei dinamika (BVD) model om die bewegingsfenomeen van hitte en massa oordrag van druiwe tydens verkoeling en koelopberging in multivlakverpakkings te voorspel, was ook by die studie ingesluit. Die totale drukverskil deur verskillende tafeldruif verpakkingssisteme is gemeet en die persentasie wat deur elke verpakkingskomponent en die vruglading bygedra is, is bereken. Van al die verpakkingskombinasies wat gemeet is, het die voeringfilms betekenisvol tot die totale drukverskil bygedra, en het gewissel van 40.33±1.15% vir die mikro geperforeerde voeringfilm tot 83.34±2.13 % vir die nie-geperforeerde voeringfilm. Die totale drukverskil oor die druiflading (1.40±0.01 % to 9.41±1.23 %) was die minste in vergelyking met die verskillende verpakkingskombinasies met die verskillende vlakke van voeringperforasies. Die verkoelingstempos van die druiwe in die 4.5 kg multiverpakking was betekenisvol (P<0.05) stadiger as vir die druiwe in die 5 kg handmandjie (‘punnet’) multiverpakking. Die 4.5 kg karton het ‘n seweagstes verkoelingstyd van 30.30-46.14% en 12.69-25.00% langer, respektiewelik, as oop-vertoon en toeslaan-‘punnet’ multiverpakkings gehad. Na 35 dae van koelopberging by -0.5°C het druiwetrosse in die 5 kg ‘punnet’-kartonkombinasies (oop-vertoon en toeslaan-’punnet’) ‘n massaverlies van 2.01 – 3.12% gehad, terwyl die trosse in die 4.5 kg kartonkombinasie slegs ‘n 1.08% massaverlies gehad het. In die ondersoek na die effek van verskillende kartonvoerings op die verkoelingstempo en kwaliteitseienskappe van ‘Regal seedless’ tafeldruiwe tydens koelopbering, het die nie-geperforeerde kartonvoerings ‘n relatiewe humiditeit (RH) van byna 100 % gehandhaaf. Hierdie hoë humiditeit in die nie-geperforeerde voeringfilms het ‘n verlies in stingelkwaliteit vertraag, maar het die voorkoms van SO2-skade en loskorrels betekenisvol (P < 0.05) verhoog in vergelyking met geperforeerde voerings. Die geperforeerde voerings het vrugverkoelingstempos verbeter, maar het die RH betekenisvol (P ≤ 0.05) verlaag. Die lae RH in die geperforeerde voerings het gelei tot ‘n verhoging in stingeluitdroging en –verbruining in vergelyking met die nie-geperforeerde voerings. Die vogverliestempo uit druiwe verpak in nie-geperforeerde voeringfilms was betekenisvol (P<0.05) stadiger in vergelyking met druiwe verpak in geperforeerde voeringfilms (120 x 2 mm and 36 x 4 mm). Die effektiewe vogdiffusiewaardes vir stingelgedeeltes verpak in nie-geperforeerde voeringfilms was stadiger as vir stingelgedeeltes wat verpak is sonder verpakkingsvoerings, en het gevarieer van 5.06x10-14 – 1.05x10-13 m2s-1. Die uitdrogingstempo van stingelgedeeltes was omgekeerd eweredig aan die grootte (deursnit) van die stingelgedeeltes. Die uitdrogingstempo van stingels wat blootgestel was (sonder voerings) aan sirkulerende koue lug was betekenisvol (P<0.05) hoër as die uitdrogingstempos van stingels wat verpak was in nie-geperforeerde voeringfilms. Empiriese modelle is gebruik om die uitdrogingskinetika van die verskillende stingelgedeeltes te beskryf. Die potensiaal van koelkamer humidifisering in die vermindering van die uitdroging van druifstingels is ondersoek. Humidifisering het stingeluitdroging vertraag en het die tempo van stingeluitdroging en -verbruining verminder, maar dit het die voorkoms van SO2-skade op die tafeldruiftrosse verhoog en het die verpakkings laat nat word. Die bewegingsfenomeen tydens verkoeling en hantering van verpakte tafeldruiwe is ook ondersoek deur gebruik te maak van ‘n BVD model en is bevestig met eksperimentele resultate. Daar was goeie ooreenstemming tussen gemete en voorspelde resultate. Die resultaat demonstreer duidelik die toepaslikheid van BVD-modelle om die optimum tafeldruifverpakkings- en verkoelingsprosedures te bepaal. / PPECB and Postharvest Innovation Programme (PHI-2) for their financial support
57

Demography, Biomass Production and Effects of Harvesting Giant Kelp Macrocystis pyrifera (Linnaeus) in Southern New Zealand.

Pirker, John Georg January 2002 (has links)
This study examined the demography of giant kelp Macrocystis pyrifera (Linnaeus) and its interactions with understorey algae and invertebrates in southern New Zealand over two and a half years. Most of the study was done at two sites within Akaroa Harbour (Banks Peninsula) but ancillary sites at Tory Channel (Marlborough Sounds) were used for parts of the study. The kelp forests within Akaroa Harbour were generally highly productive, with a high annual turnover of giant kelp. Macrocystis plants were mostly annual and rarely reached ages greater than 12 months. Peak recruitment occurred in spring (November) during 1995-97, but lesser recruitment episodes occurred throughout the year. The maximum growth rates of Macrocystis fronds were comparable to rates reported elsewhere in southern hemisphere populations (22 mm - 24.5 mmlday), but considerably lower than those in northern hemisphere populations. The major experiment incorporated in the study tested the effects of the Macrocystis canopy and the understorey canopy of the stipitate laminarian Ecklonia radiata on macroalgae and invertebrates. The experiment was structured so that the effects of clearances at different times could be determined. One impetus for this experiment was the need to address issues relating to the commercial harvesting of giant kelp, its sustainability and its effects on other species. The effects of canopy removals on understorey algae, mostly juvenile Macrocystis, Ecklonia and Carpophyllum spp, were highly dependent on the timing of canopy removals and the combinations of canopies removed. For example, winter harvests of the Macrocystis canopy alone enhanced the survival of post-settlement Macrocystis recruits, but had little effect on Ecklonia recruitment. However, when both Macrocystis and Ecklonia canopies were removed in spring, there was heavy recruitment of Ecklonia that grew to dominate the understorey. Strong inter and intraspecific interactions from the Macrocystis surface canopy appeared to have been reduced by physical factors including water turbidity, sedimentation and the deterioration of the surface canopy during summer. These physical factors were not as limiting in Tory Channel. Fine scale extrinsic factor effects including nutrients, light and grazing on the early life history of Macrocystis were investigated in small experiments. Results suggest that recruitment may be nutrient limited even at moderately low temperatures, and that small herbivorous gastropods are an important source of mortality in the early life stages of Macrocystis. Culturing and transplantation cultivation techniques were also examined as a means of supplementing algal supplies. Macrocystis was cultured successfully through its life cycle onto culture ropes, but generally failed to produce visible sporophytes when placed in the field. Cultured plants did grow in Tory Channel, however. Juvenile plants transplanted to ropes for on-farm cultivation showed little growth during summer, but the addition of nutrients significantly enhanced growth rates of these plants during warmer months when natural nutrient levels were low. Increased growth rates at the onset of winter and with the addition of nutrients during summer confirmed that low nutrient levels during summer are growth limiting. Akaroa Harbour kelp forests exhibited considerable variation in Macrocystis canopy biomass through time. For example, the 32,000 m2 kelp forest at Wainui had a biomass of 144 t in October 1995, which then decreased to 21 t in October 1996. Canopies tended to deteriorate during summer. Thus, at Ohinepaka Bay kelp forest had a biomass of 31 t during winter 1997, which decreased to 0.06 t the following summer. The greatest reduction in biomass, however, coincided with a period of hugely increased sediment, which smothered blades in the sea-surface canopy, covered the substratum, and prevented successful recruitment of kelp for over a year. Nutrient depletion was one of several factors thought to cause the summer deterioration of the Macrocystis sea-surface canopy, which has important ramifications for the commercial harvesting of Macrocystis pyrifera in summer. Management considerations and options are discussed in relation the commercial harvesting of Macrocystis in New Zealand. The major conclusion of this study is that although Macrocystis was able to form dense surface canopies during winter its ability to dominate kelp forests was constrained by physical factors, especially sedimentation, high turbidity, nutrients, and storms. The lack of strong interactions between Macrocystis and Ecklonia are also largely a result of their different life history characteristics. Overall, there appear to be no significant negative flow-on effects resulting from kelp harvesting and it appears that Macrocystis can be harvested sustainably.
58

Harvest Losses Decreased

Machado, Marshall 02 1900 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
59

Adjuvants for Enhancing the Performance of a New Cotton Defoliant

Carasso, F. M., Briggs, R. E. 02 1900 (has links)
No description available.
60

Cotton Harvest - Aid Chemicals

Taylor, B. B., Briggs, R. E. 02 1900 (has links)
No description available.

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