Dissertations / Theses on the topic 'Potato industry'

Potato (Solanum tuberosum L.) varieties Atlantic and Granola are widely grown in Indonesia. The optimal method of cultivation in the tropics, due to the susceptibility of cut seed for disease, is by small (20 to 55 g) whole seed potatoes. However, the variety Atlantic produces mostly large tubers, which are not suitable for planting as whole seeds. Although Granola produces a reasonable proportion of small tubers it still produces a few in the larger size grades and there is no fresh market in Western Australia for the larger tubers for this variety. The aim of this study was to develop methods to be used in Western Australia that improve the yield of small seed potatoes for export to Indonesia. The influence of seed-potato storage duration (at 4°C) on subsequent stem growth was assessed after 30 days growth in a glasshouse (22°C/18°C, day⁄night). Seed potato storage for 22-28 (Atlantic) and 24-30 (Granola) weeks resulted in development of higher numbers of stems. A series of field experiment were designed to increase yield of small tubers. Apical sprout removal in Granola, but not Atlantic, increased the number of stems (by 27%), yield of 20-55 g potato (by 32%) and total yield (by 17%). Application of herbicide (paraquat + diquat) at low concentration during early tuber initiation decreased total yield in Atlantic (by 14%) and Granola (by 16%). Treating whole seed potatoes with carvone vapor two weeks before planting had no influence on stem or tuber number in both Atlantic and Granola but in Atlantic only, the total yield was reduced by 12%. Spraying plants with paclobutrazol during early tuber initiation inconsistently influenced tuber number and yield between the two varieties and two experiments. The influence of gibberellic acid (GA3) on stem number, total tuber number, yield of 20-55 g tubers and total yield was investigated by dipping seed pieces in a GA3 solution (20 mg⁄L) two days prior to planting. In Atlantic, GA3 treatment increased stem number (by 147%), total tuber number (by 75%) and yield of 20-55 g tubers (by 330%) without influencing total yield. In Granola, GA3 treatment increased stem number (by 50%), total tuber number (by 15%), yield of 20-55 g tubers (by 21%) and total yield (by 10%) The influence of gibberellic acid application (20 mg⁄L) to seed pieces before planting increased the number of small tubers through increased stem number. The shift toward a greater proportion of small tubers, without reducing total yield, had a greater influence in Atlantic than that in Granola. Treatment of GA3 and paclobutrazol together decreased total yield compared to that of GA3 alone

Spatial shifts and structural changes continue to occur in the United States agricultural industry. Researchers have documented that the potato industry has changed in response to demands of consumers, expectations of producers and improvements in research and development. The aim of this study was to provide empirical evidence that both institutional and infrastructural factors are important to potato production in North Dakota. Using secondary county-level potato production data for North Dakota, an empirical model was designed to estimate the direction and impact of growers' expectations of prices, yields and costs on their decision to produce potatoes. The results confirmed that institutional relationships established between growers and processors, as well as the infrastructure that growers have in place from one growing season to the next, are statistically significant in determining the total number of potato acres planted.

The Japanese vegetable market is characterized by a general tendency towards the concentration of production by region. Amongst all vegetables, potato production has the highest level of concentration. Eighty-six percent of the total market quantity is accounted for by Hokkaido, the largest production prefecture amongst the 47 prefectures in Japan. The Herfindahl Index for prefectures in the Japanese potato market was 0.74 in 1994, indicating that the fewness of producers was equivalent to a market where total output was shared equally by only 1.35 producers. Under this highly concentrated situation, existence of monopolistic power, or more generally, oligopolistic power, of the large scale producers can be suspected.
In this thesis, the level of competition in the Japanese Potato market was evaluated employing conjectural variations analysis based on a monthly data for 1989 to 1995 to reveal the nature of the market. Four wholesale markets, in four large consumption areas, and eight production areas in differ ent geographical locations in were analyzed.
The conclusion from the results of the empirical analysis is that, despite the high level of concentration in production, all producing regions including the dominant producer, Hokkaido, seem to have behaved competitively.
One implication for the competitive behavior of these large producers is the imperative to maintain their share in the market against potential competitors, resulting in price setting close to the marginal cost.

Poor quality seed is the major constraint limiting both the productivity of potato crops and the expansion of the potato industry in Vietnam. Despite numerous attempts to establish a certified seed system, the most practical solution is to import clean foundation seed of the desired variety and physiological age. With imports from Europe and North America proving to be immature and too expensive, Western Australia (WA) has emerged as a potential source of high quality seed. While seed imports from WA are unique in that the varieties imported have been selected by researchers in Vietnam as being suited to the agro-ecological environment in the Red River Delta (RRD), no assessment of the economic benefits to smallholder potato farmers from the use of WA potato seed has been undertaken. In 2006/08, the yield and profitability of three potato varieties Eben, KT3 and Atlantic in two locations were compared where the crops had been derived from new seed imported from WA (VN0), seed derived from crops cultivated in the RRD after one generation (VN1) and two generations (VN2). There was a significant difference in the yield produced between the three different seed sources but not between the locations. For all varieties, and in both years, the yield decreased with the number of multiplications in Vietnam. Furthermore, the marketable yield declined significantly from the first crop (VN0) to the third crop (VN2). The decline in yield and tuber quality with each successive generation was associated with an increase in PVY and PVX infection. Not unexpectedly, differences in yield and marketable yield between the seed generations had a significant impact on the gross income for each variety.VN0 seed of all varieties produced the highest gross income (VND 2.4 to 4.1 M/sao) compared to VN1 (VND 1.9 to 3.1 M/sao) which was significantly higher than VN2 (VND 1.4 to 2.4 M/sao). However, while high quality seed is more productive, it is also more expensive. As a result, significant differences were observed between the seed costs. VN0 seed was almost two times more expensive (VND 10,500 – 11,000 per kg) than VN1 and VN2 seed (VND 6,000 – 6,500 per kg). Despite the higher costs, VN0 seed provided the highest net incomes compared to VN1 which was significantly higher than VN2. Farmers who retained seed received a higher net income (VND 0.13 – 0.6 M/sao) than those who did not retain seed. Ways to improve the accessibility of affordable, high quality potato seed to farmers in the RRD are discussed.

The purpose of this thesis is to design a computer model which compares three sprinkler irrigation systems---portable pipe with volume gun, traveller with volume gun and towable/non-towable centre pivot---for potato production. The model user is required to enter a set of basic data: crop and field conditions, irrigation technical parameters and basic economic data, following which the model establishes the preliminary irrigation system and a comparative investment analysis. The model was applied and tested on a potato farm situated in Notre-Dame-de-la-Paix (southwestern Quebec). Based on a 14-year climatic analysis, supplemental irrigation for a normal rainfall growing period (368 mm) was estimated at 250 mm. The application of the model indicates that for a normal rainfall period with an assumed yield increase of 25% over non-irrigated production, all three systems provide net profits (increases of 11% to 50%). However, when determining the Internal Rate of Return (IRR) on a 10-year period, the maximum rate attained by the more profitable systems---portable pipe and non-towable centre pivot (both with an electric pump)---was 14%, a rate inferior to the IRR for non-irrigated production (17%). The Net Present Value (NPV) analysis for the two most profitable irrigation systems provided a slightly higher NPV value for irrigated than for non-irrigated production ($10,942---irrigated vs $10,522---non-irrigated production). The payback period for those two irrigation systems was 7 years. Greater gains of irrigated over non-irrigated yields would be expected for a dry period because of low and unpredictable yields in non-irrigated conditions. A farmer planning to invest in an irrigation system must carefully investigate all technical and socio-economic aspects. The model presented gives the farmer a useful tool with which to do this.

Poor quality seed is the major constraint limiting both the productivity of potato crops and the expansion of the potato industry in Vietnam. Despite numerous attempts to establish a certified seed system, the most practical solution is to import clean foundation seed of the desired variety and physiological age. With imports from Europe and North America proving to be immature and too expensive, Western Australia (WA) has emerged as a potential source of high quality seed. While seed imports from WA are unique in that the varieties imported have been selected by researchers in Vietnam as being suited to the agro-ecological environment in the Red River Delta (RRD), no assessment of the economic benefits to smallholder potato farmers from the use of WA potato seed has been undertaken. In 2006/08, the yield and profitability of three potato varieties Eben, KT3 and Atlantic in two locations were compared where the crops had been derived from new seed imported from WA (VN0), seed derived from crops cultivated in the RRD after one generation (VN1) and two generations (VN2). There was a significant difference in the yield produced between the three different seed sources but not between the locations. For all varieties, and in both years, the yield decreased with the number of multiplications in Vietnam. Furthermore, the marketable yield declined significantly from the first crop (VN0) to the third crop (VN2). The decline in yield and tuber quality with each successive generation was associated with an increase in PVY and PVX infection. Not unexpectedly, differences in yield and marketable yield between the seed generations had a significant impact on the gross income for each variety.
VN0 seed of all varieties produced the highest gross income (VND 2.4 to 4.1 M/sao) compared to VN1 (VND 1.9 to 3.1 M/sao) which was significantly higher than VN2 (VND 1.4 to 2.4 M/sao). However, while high quality seed is more productive, it is also more expensive. As a result, significant differences were observed between the seed costs. VN0 seed was almost two times more expensive (VND 10,500 – 11,000 per kg) than VN1 and VN2 seed (VND 6,000 – 6,500 per kg). Despite the higher costs, VN0 seed provided the highest net incomes compared to VN1 which was significantly higher than VN2. Farmers who retained seed received a higher net income (VND 0.13 – 0.6 M/sao) than those who did not retain seed. Ways to improve the accessibility of affordable, high quality potato seed to farmers in the RRD are discussed.

The Australian potato industry is threatened by inadequate measures to control the virus health of seed potatoes. Potatoes are vegetatively propagated; therefore infection can result in disease spreading through generations. This has the potential to cause significant economic losses. Virus testing on tuber sprouts is currently conducted by ELISA, however a significant time delay of several weeks can occur while tubers sprout. There is a considerable need for a rapid, quantitative and cost effective virus test directly on bulked samples of dormant tubers to identify infected lots during seed multiplication. The potato viruses of economic importance in Western Australia are Potato virus S, (PVS), Potato virus X, (PVX), Potato leafroll virus, (PLRV) and Tomato spotted wilt virus (TSWV). The main aim of this project was to develop reliable PCR-based methods for multiplex real-time quantitative detection of these viruses in bulked potato tuber samples for seed certification for domestic and export markets. Knowledge of the distribution of the viruses within tuber tissue was needed to develop more effective methods of RNA extraction. The distribution of the viruses in histological sections of potato tubers was investigated using immunohistochemistry and in situ hybridization. All four viruses were found to be distributed at the stolon end of freshly harvested infected potato tubers. Extraction of RNA from tuber tissue is problematic because it contains starches and phenolics which inhibit RT-PCR. Extracting RNA from the tuber peelings would overcome this problem; however one of the viruses, PLRV, is restricted to the phloem in potato tubers. The distribution of the phloem in the superficial tissue of potato tubers was therefore investigated using histological staining and transmission electron microscopy. The vascular tissue was found to be within 2 mm below the epidermis of the tuber. With this knowledge, total RNA was extracted rapidly and efficiently from bulked potato peelings equivalent to 300 dormant tubers to detect single infections of PLRV, PVX, PVS and TSWV. For the quantitative detection of these viruses in potato leaves and tuber tissue, specific primers and fluorescent-labeled TaqMan® probes were designed. A realtime multiplex, single tube RT-PCR assay was developed. The main tasks involved primer design, optimization of reagents, standardization of RNA samples from which standard curves for analysis were generated, and identification of a baseline on which to interpret results. Limits of detection sensitivity were established using a range of virus transcript copy numbers (8 x 101 to 8 x 109 copies of PVX and PVS, 1 x 102 to 1 x 1010 copies of PLRV and 1 x 103 to 1 x 1010 copies of TSWV). The multiplexed assay was validated in blind studies. This high-throughput test is accurate and sensitive, and as a result this test is in the process of being commercialized and used by the seed potato industry of Western Australia as a cost-effective diagnostic tool to detect viruses reliably in bulked samples of dormant potato tubers.

This thesis is concerned primarily with the export marketing performance of the Northern Ireland seed potato industry. The Industry has shown a dramatic decline in exports over the past twenty years, and this thesis proposes strategies aimed at regaining, and maintaining, a competitive advantage for the industry in world markets. A comparative analysis is conducted of the strategic and organisational export capabilities of the Northern Ireland industry and its main competitors. In addition, an analysis of the requirements of major world seed potato markets is undertaken. Academically, the thesis aims to apply the principles of export marketing to a traditionally managed sector of agriculture. As such, it is hoped that the thesis makes a useful contribution to the literature on agricultural marketing and export marketing. Major academic themes explored in the thesis include - Globalisation versus 'customisation' - New product development strategy and export success - Product-life-cycle analysis and product-enhancement strategies - Export promotional strategies - The utility of horizontal and marketing performances - 'Market spreading' versus 'key market concentration' vertical integration in enhancing - Centrality or peripherality of the export function The central hypothesis explored in the thesis is that in an agricultural industry, such as a seed potato one, where production is fragmented over a. large number of small production units, then a necessary prerequisite to successful strategic exporting is the existence of an appropriate organisational structure to carry out the strategic tasks. This hypothesis is confirmed by the findings of the research. As the product and service requirements of world seed potato markets have changed over the years, and are becoming more sophisticated, the Northern Ireland industry has been unable to adopt an appropriate customisation strategy in response. This is due to the inhibiting effect of an inappropriate organisational structure within the industry. By way of contrast, industries which have developed considerably by responding to changing market requirements (such as the Netherlands, France and Scotland) are characterised by a strongly integrated organisational structure (both horizontal and vertical). In all these countries this has largely been achieved by the development of marketing co-operatives. In seeking to propose export marketing strategies for the Northern Ireland industry therfore, a necessary prerequisite is to establish an appropriately integrated organisational system within the industry. As the seed potato marketing co-operative Expotato Limited has already begun to introduce a horizontally and vertically intergrated discipline into the Northern Ireland industry, it is suggested that this co-operative should be further developed as a catalyst for positive organisational and strategic development of the industry ...[cont.].

Adequate supply of healthy planting material, at reasonable prices, is of critical importance to the functioning of the potato industry. True Potato Seed (TPS) technology offers an alternative way to produce potato planting material, based on the use of botanical potato seeds. This study investigates the hypothesis that the use of TPS technology, in a similar way as practised in the USA, will be beneficial to the European Union. It is assumed that the TPS varieties that have been bred in the USA are also capable of meeting the demands of the EU markets. The current status of the EU potato industry and the working of TPS technology are reviewed. As part of this study botanical potato seeds from nine TPS varieties that are commercially available in the USA, have been imported into and used to initiate the first ever field trials within the European Union. A large mathematical model has been purposely built to simulate the uptake of TPS technology by the EU potato industry, and to assess the agronomic and economic effects. The modelling results of various scenarios all indicate that the use of TPS technology would bring economic and agricultural benefits to the EU. The annual savings could be as high as 130 million ECU per year, whilst reducing the potato growing area with up to 72,000 ha. Implications of these finding, and current limitations for the uptake of TPS technology inside the EU are discussed.

At the start of 2010, the National Energy Regulator of South Africa (NERSA) announced that electricity tariffs would increase at an average rate of 25 percent per year over a three year period (Njobeni, 2010). This raised fears within the economy and specifically within the agricultural sector that these increases would negatively impact the agricultural sector. Various stakeholders within the agricultural sector also raised opinions on what the true impact will be on agricultural production and market prices. The main objective of this study was to quantify the true impact of higher electricity tariffs on production and market prices within the potato industry. The study focused on the potato producing regions of the Sandveld, Limpopo and South Western Free State. On-farm data were collected in an attempt to capture the electricity consumption and costs associated with potato farming in these specific regions. An effort was also made to calculate and capture production costs in these three regions which, together with the collected electricity costs, formed the basis of the analysis. The study applied a supply response model developed by the Bureau for Food and Agricultural Policy to evaluate the impact of increased electricity tariffs on potato production and prices in South Africa. The supply response model used is a standard econometric recursive dynamic model that has the purpose to model policy analysis, iv with short, medium and long term projections on an annual baseline basis (van Tongeren et al, 2000). However, in order to conduct analysis on electricity tariff increases, this supply response model required adaptation and improvement in order to incorporate electricity costs. Before this adjustment, the model applied the producer price / fertilizer price ratio as a proxy for production costs. Since detailed production costs (including electricity costs) were acquired through this study it was now possible to alter this ratio to a producer price / production costs ratio which included the electricity costs. To illustrate the impact of the electricity price increase the electricity cost component in production cost was shocked to reflect an increase at the set rate of an average of 25 percent per annum for the 2010, 2011 and 2012 production years. The results demonstrated that these three regions will see a decrease in hectares planted over the period between 2013 and 2020 as a result of the increased electricity tariffs, but that this decrease in hectares planted will be very small. The Sandveld region had the highest impact as it was calculated that on average, over the period between 2013 and 2020, a total of 35 hectares of potato production will be lost due to this higher electricity tariff. It can further be expected that the market price in the Sandveld region would increase slightly by 52c/10kg over the same period. The South Western Free State region was least effected by the higher electricity tariffs as a mere 1.6 hectares of potato production land could be lost due to the higher electricity tariffs which will lead to an increase of around 36c/10kg in market prices over the period between 2013 and 2020. The study further introduced a cost saving technique that farmers can use to counter the higher electricity tariffs. The majority of farmers consume electricity under the Landrate and Ruraflex tariff structure. It is this Ruraflex tariff structure that farmers can use to their advantage by consuming electricity during specific periods of the day that would result in a lower c/kWh cost. By reviewing the irrigation scheduling and activities of farmers the study established that most farmers pay far too much for electricity since their peak usage are during the periods of the day where higher rates apply. The study calculated that farmers, by applying this technique, could save between R190 and R455 on electricity costs per hectare in the Sandveld region. The study concluded that the impact of higher electricity tariffs on potato production and market prices in the Sandveld, Limpopo and South Western Free State regions are of a small nature which will most likely be absorbed by the farmers. The claims by various industry participants that the potato industry would be adversely negatively impacted were unfounded in this study. Nevertheless, in the event that electricity tariffs continue to increase in the future, farmers have to their disposal a cost saving technique that will aid them in countering some of the negative effects of electricity price hikes.
Dissertation (MCom)--University of Pretoria, 2012.
Agricultural Economics, Extension and Rural Development
unrestricted

The purpose of this research was to incorporate a potato product into bread as a partial replacement for wheat flour and to describe a collaborative process for the development of bread products in three Soviet communities. Six potato flake breads and six cooked-mashed potato breads, with and without added gluten, were evaluated in a pilot study. Consumer acceptance scores indicated no significant differences among the twelve bread products. Four bread products, 29% and 45% cooked-mashed potato breads without added gluten, 15% potato flake bread with added gluten, and a 100% wheat flour bread, were selected for objective measurements, descriptive sensory evaluation, and central location acceptance testing. The four breads were not significantly different in the objective measurements of standing height, percent protein and amino acid content The three potato breads had the highest moisture percent loss on day 1. Texture analysis indicated the 45% bread had the highest texture measurements from the day of baking through day 4. The control "rapid" bread had the lowest analysis of freshness measurements. Staling, as measured by differential scanning calorimetry, indicated the potato breads had significantly reduced staling rates when compared to 100% wheat flour bread. Eleven trained panelists judged ten characteristics of the control and potato breads. The panelists perceived the potato breads to be more moist than the control. The other sensory characteristics of the control and potato breads were judged as similar. Central location acceptance testing in Alaska and the Soviet Far East indicated that the potato breads were acceptable and consumers indicated they would buy the breads if they were available. Across all locations the locally purchased control bread was liked significantly less than the potato breads. A collaborative process was designed for development of food products in Soviet and Alaskan communities.
Ph. D.

Thesis (MBA)--Stellenbosch University, 2001.
ENGLISH ABSTRACT: This study evaluates the use of information technology as a method to reduce production risk for irrigated potatoes. Risk in agriculture is discussed under climatic, market or price and production related risk. Production related risk covers the disciplines of planting, irrigation, fertilisation, disease and pest control as well as harvesting. It is in the above mentioned disciplines that information technology could possible be applied to reduce production risk in irrigated potatoes. The nature of this study can therefor be described as the investigation of the economic justification of information technology as a method to reduce production risk in irrigated potatoes. A brief introduction to put potato production in world and South African context into perspective, is provided. In South African context the importance and position of potato production relative to other crops is discussed. To better understand the economic conditions, under which potatoes are produced in South Africa, a financial breakdown of production cost for irrigated potatoes over regions is given. It is important to understand the economics of potato production before a proper assessment of thepossible benefits of information technology can be made. Various principles and instruments involved with information technology, as it applies to potato production under irrigation are also discussed. Irrigation scheduling as a discipline in which information technology can be applied, is also discussed. It is important to understand that irrigation scheduling can be based on two underlying principles, i.e. atmospheric modelling and soil moisture measurement. Various examples of measurement instruments are discussed. Climatic based disease modelling and petiole sampling as a method to determine nutritional status in the potato plant, was also discussed. A brief discussion of computerised agriculture management software was included to conclude the discussion on the principles and instruments available for information technology in irrigated potato production. The use of fertiliser scheduling, irrigation scheduling and climatic modelling to reduce fungal diseases in potatoes, as information technology methods, are explained in greater detail. It is shown that recommended levels for various nutrients do exist and that petiole analysis as a method to determine these levels at various growth stages, can be applied successfully. It is further argued that with various methods of irrigation scheduling, proper decision making about the amount and timing of irrigation needed, can be possible. The Plant-Plus system as a method to better control Late Blight on potatoes, is discussed. The results obtained through a commercial trial proves the validity of climatic modelling as a method of information technology to reduce production risk on potatoes, specifically the risk associated with Late Blight. The existence of and results obtained through the equipment and methods previuosly mentioned, raises the question of the economic viability of information technology at farm level. To investigate the perception of growers with regard to the applicability of information technology to reduce production risk and their readiness to adopt such . -- technology, a questionnaire was sent to 40 commercial potato growers throughout South Africa. Growers were tested on their perception with regard to the use of information technology on aspects such as financial management, irrigation scheduling, fertilisation, climatic measurement for fungal modelling as well as a profile analysis of the grower. The results of the survey are tabulated and analysed. Growers were on average positive about the value of information technology and indicated that under certain conditions, they were prepared to implement such technology. Margins in commercial potato production are under severe pressure and are in fact shrinking. Case studies presented in this investigation and results from the pilot survey indicate that the use of information technology is not only important for the reduction of risk in potato production but also imperative for sustainable and profitable potato production. It can therefore be concluded that, based on the results obtained in the pilot questionnaire, a statistical valid sample would probably support the findings in the pilot study. The pilot study indicated that reliable, affordable and practical information technology, as it has been presented in this investigation, does have a place in modern day irrigated potato production.
AFRIKAANSE OPSOMMING: Hierdie studie evalueer die gebruik van informasie tegnologie as 'n metode om produksie risiko in die verbouing van aartappels onder besproeiing, te verminder. Risiko in landbou word onder klimatologiese, mark of prys en produksie verwante risiko bespreek. Produksie verwante risiko kan weer onderverdeel word in risiko wat verband hou met plant of vestiging, besproeiing, bemesting, plaag en pes beheer asook oes. Dit is dan in die bogenoemde dissiplines waar informasie tegnologie moontlik aangewend kan word om produksie verwante risiko te verminder. Die kern van hierdie ondersoek kan gevolglik saamgevat word as 'n ondersoek na die ekonomiese regverdigbaarheid van informasie tegnologie as 'n metode om produksierisiko in die verbouing van aartappels onder besproeiing, te verminder. Daar word kortliks verwys na aartappel verbouing in wêreld en Suid Afrikaanse konteks. In Suid Afrikaanse konteks is die relatiewe belangrikheid van aartappelverbouing in vergelyking met ander gewasse uitgelig. Ten einde 'n beter begrip vir die ekonomiese omstandighede waaronder aartappels in Suid Afrika verbou word, word 'n afbraak van produksiekoste oor streke verskaf Dit is belangrik om die ekonomie van aartappelproduksie te verstaan voordat 'n deeglike evaluering van die moontlike voordele wat informasie tegnologie kan inhou, onderneem kan word. Verskeie beginsels en instrumente in die aanwending van informasie tegnologie, soos van toepassing in die verbouing van aartappels onder besproeiing, word ook toegelig. Hieronder word besproeiingskedulering as 'n metode bespreek. Dit is verder belangrik om te besef dat besproeiingskedulering op hoofsaaklik twee beginsels berus naamlik atmosferiese modellering en fisiese grondvog meting. Verskeie voorbeelde van meetinstrumente word bespreek. Klimatologiese siektemodellering en petioolontledings as 'n metode om die voedingstatus van aartappelplante te bepaal, word ook bespreek. Die gebruik van bemestingskedulering, besproeiingskedulering en klimatologiese modellering vir die beheer van laatroes op aartappels, as metodes van informasie tegnologie, word in groter besonderhede toegelig. Daar is aangetoon dat aanbevole peile vir verskeie nutriënte bestaan. Deur die neem van gereelde petiool ontledings kan hierdie peile suksesvol gedurende die opeenvolgende fenologiese stadia van die aartappelplant, gehandhaaf word. Daar is verder aangevoer dat deur die gebruik van verskeie metodes van besproeiingskedulering, deeglike besluitneming rakende die hoeveelheid en tydsberekening van 'n besproeiing, moontlik is. Die Plant-Plus sisteem as 'n metode om laatroes op aartappels te beheer, is toegelig. Resultate behaal in 'n kommersiële aanplanting het die geldigheid van klimatologiese modellering as 'n metode om produksierisiko - veral die risiko geassosieer met laatroes - te verminder, onderskryf. Die bestaan van resultate en instrumente soos voorgehou in Hoofstukke 3 en 4, onderskryf of bevestig die vermoede dat informasie tegnologie wel aangewend kan word om produksierisiko in aartappelverbouing te verminder. Die vraag is egter of dit ekonomies op plaasvlak aangewend kan word. Ten einde die persepsie met betrekking tot - die toepaslikheid en gereedheid van produsente in dié verband te evalueer, is 'n loodsvraelys na 40 respondente, wat die kommersiële aartappelprodusente regdeur Suid Afrika verteenwoordig, gestuur. Respondente is ge-evalueer met betrekking tot hul persepsie rakende die gebruik van informasie tegnologie in die dissiplines van finansiële bestuur, besproeiingskedulering, nutriëntskedulering en klimatologiese modellering vir die beheer van laatroes. Respondente was oor die algemeen positief met betrekking tot die nut van informasie tegnologie en dat onder seker voorwaardes, hulle dit sal gebruik. Marges in kommersiële aartappelverbouing is onder ernstige druk en is inderdaad besig om te krimp. Gevallestudies wat in hierdie ondersoek voorgehou is, asook resultate verkry uit die vraelys, dui aan dat informasie tegnologie nie alleen belangrik is vir die vermindering van risiko in aartappelverbouing me, maar ook noodsaaklik IS vir volhoubare en winsgewende aartappelproduksie. Dit kan gevolglik gestel word dat resultate verkry uit die loodsvraelys, daarop mag dui dat 'n statisties verifieerbare steekproef moontlik kan uitwys dat betroubare, bekostigbare en praktiese informasie tegnologie, soos voorgehou in hierdie ondersoek, wel 'n bestaansreg in die moderne verbouing van aartappels onder besproeiing het.

The main purpose of this thesis is to empirically calculate the welfare changes which might be expected to result from potato yield reductions caused by ambient ozone loadings in the Lower Mainland of British Columbia. The objectives of the research are: (1) to review the scientific literature pertaining to the effects of ozone loadings on agricultural crops; (2) to review the methodologies employed in previous regional economic assessments of ozone damages; and (3) to apply an economically defensible technique to the analysis of welfare losses due to ozone. Ozone in the Lower Mainland may be pictured as being restricted laterally by the mountain ranges surrounding Vancouver, and vertically by stagnant high pressure systems. Land/sea breezes aid in transporting ozone and its precursors from Vancouver up the Fraser Valley towards important crop growing regions. The highest levels of ozone occur during spring and summer coinciding with the most active season for many crops. Seasonal ambient ozone dose, measured as hours-ppm>0.10ppm was found to be high in rural areas, especially Abbotsford, during the late 1970's and early 1980's, dropping to low levels in more recent years. Potatoes are one of the economically important crops in the Lower Mainland known to be sensitive to ozone. Potato tuber weight reductions are estimated to have reached 16.5 percent in the Abbotsford region in 1981 at seasonal ambient ozone loadings. An aggregate supply/demand model is set up for potato production in B.C. based upon prior estimates of supply and demand elasticities. This model assumes the price in the B.C. market is set exogeneously by U.S. imports. Thus, all policy relevent welfare changes affect producers' quasi-rent alone. Sensitivity of the model to import price, and the price elasticity of supply is tested. A range of welfare estimates is reported for a variety of ambient ozone loadings. The total damages to potato producers, assuming all regions of B.C. are affected by the same seasonal dose as Abbotsford, are calculated to be around one million dollars at ambient ozone loadings in four out of eight years. A peak occurred in 1981 at 2.4-2.9 million dollars total damages. Damages may be overestimated because 20-30 percent of potato production takes place outside the Lower Mainland, Abbotsford often appears to receive higher ambient ozone loadings than other regions, and not all potato cultivars grown in the Lower Mainland are as sensitive to ozone as that employed here. However, there are also reasons to be cautious over discounting these estimates as too large. Potato response to ozone is restricted to tuber weight reductions while other important effects may include increased plant stress and damage to crop quality. In addition, missing air quality information for some years and stations, suggests that actual ozone dose could be higher than calculated.
Science, Faculty of
Resources, Environment and Sustainability (IRES), Institute for
Graduate

Україна одна з не багатьох країн, яка має природні запаси майже всіх цінних й корисних хімічних елементів, багато яких міститься у кількості достатній для організації промислових виробництв. З відходів калійного виробництва можна отримати тисячі тон цінної хімічної продукції, серед яких й необхідні калійні добрива, яка Україна імпортує, кухонна сіль, хлорид магнію, сполуки рідкоземельних елементів та інші.
Ukraine is one of the few countries that has natural reserves of almost all valuable and useful chemical elements, many of which contain in an amount sufficient to organize industrial production. With potash production waste can be thousands of tons of valuable chemicals, including fertilizers and necessary potassium, which Ukraine imports, salt, magnesium chloride, compounds of rare earth elements and others.

Autor no autoriza el acceso a texto completo de su documento hasta el 30/1/2020.
Ingeniero Civil Industrial
El presente trabajo de memoria trata acerca del mejoramiento de los estándares de pureza de material producidos en una planta de producción de nitrato de potasio (KNO_3) de una empresa particular del rubro de la minería no metálica. El nitrato de potasio es un compuesto químico usado en distintas industrias, como por ejemplo, farmacéutica y de explosivos. El producto desarrollado por la empresa corresponde a la industria agrícola, donde es usado como fertilizante. Según información de la Comisión Chilena del Cobre, en los últimos 10 años, ha disminuido un 45,8% su producción nacional de nitrato llegando a 759,4 toneladas al año el 2013, mientras que su precio ha ido al alza llegando a US$ 800 por tonelada el 2013, es decir, un aumento del 179,6% . Se abre una gran oportunidad de negocios, dado el alza en los precios, que esta memoria pretende aprovechar, sin embargo, no toda la producción cumple con los estándares de pureza que se requieren para su comercialización. Es por ello que este trabajo se enfoca en la disminución del porcentaje de producción defectuosa del nitrato de potasio. El proceso productivo para este compuesto consta de 4 plantas de procesamiento. En cada planta están involucradas variables químicas y de control. Las plantas están conectadas en serie, donde el flujo de material pasa en cada una y luego de un tiempo determinado pasa a la siguiente. En total se demora 36 horas generando flujos de descarte o deshecho y dos flujos de producto final. Para realizar el trabajo, se usa el campo de la minería de datos, el cual, mediante la metodología Knowledge Discovery in Databases para elaborar modelos explicativos y predictivos, y así descubrir relaciones entre las variables que interactúan en la producción. A la vez, se utiliza dos tipos de modelos, de clasificación y de regresión, de manera de comparar y decidir qué forma de predicción es más conveniente, estimar la categoría de pureza o predecir el nivel de contaminación. Se generaron 4 ecuaciones para describir los contaminantes KClO_4 y NaCl en las dos corrientes de salida que tiene el proceso. Se implementaron 6 algoritmos de data mining, 3 de clasificación y 3 de regresión, de los cuales Support Vector Machine y Random Forest Regression permitieron explicar de mejor forma las ecuaciones. Los modelos de regresiones dieron mejores resultados que los de clasificación dado que los primeros, a pesar de subestimar la producción de material impuro, presentan mayor precisión a la hora de predecir la categoría del producto. El modelamiento permite disminuir la impureza histórica de cada contaminante, en cada corriente, desde un 11% a un 7% promedio. Además, se generan rangos donde las variables pueden variar un 4,5% sin que la impureza del sistema aumente. Finalmente, a nivel económico, los modelos permiten generar 6.833 toneladas anuales en la corriente L, equivalentes a unos 4,5 millones de dólares al año.

La régénération des solutions de lavage utilisées en Nettoyage En Place (NEP) présente un intérêt, tant économique qu’environnemental, pour les industriels laitiers. L’étape clé du NEP réside dans le lavage alcalin qui assure l’élimination des souillures organiques déposées sur les équipements. Ce lavage est généralement effectué par des lessives de soude, moins onéreuses que celles de potasse. Nos travaux ont visé à appliquer un procédé physico-chimique de régénération à des lessives de potasse en vue de rentabiliser leur intégration au NEP laitier. La régénération de solutions de potasse souillées par du lait a été examinée et comparée à celle de solutions de soude. L’efficacité du procédé à épurer les solutions de potasse en termes d’abattement de la DCO et de Ntot a été démontrée. L’analyse des solutions régénérées a par ailleurs mis en évidence l’amélioration de leurs propriétés interfaciales (tension superficielle, angle de contact). Ces propriétés, dont l’origine a pu être attribuée à l’accumulation de biotensioactifs, confèrent aux solutions de potasse régénérées un meilleur pouvoir nettoyant. Ce point a été validé lors d’essais de nettoyage de membranes organiques d’ultrafiltration colmatées par des protéines laitières. L’optimisation de la formulation de ces solutions a permis l’obtention de performances de nettoyage comparables à celles d’un détergent commercial classiquement utilisé pour ce type d’application. Enfin, les impacts économiques et environnementaux de l’intégration de lessives de potasse en substitution à celles de soude ont été évalués pour un NEP laitier industriel au travers d’une étude technico-économique et d’une Analyse de Cycle de Vie (ACV)
The regeneration of Cleaning In Place (CIP) solutions is interesting, both economically and environmentally, especially in dairy industry. The CIP’s key step lies on the alkaline washing which ensures the removal of organic contaminants deposited on the equipment. This washing is generally done by soda lyes, less expensive than potash ones. Our work aimed to apply a physicochemical regeneration process, based on adsorption-coagulation-flocculation phenomena, on potash lyes to make their integration in the dairy CIP affordable. The regeneration of potash solutions soiled with milk was examined and compared with the soda solutions regeneration. The process effectiveness to purify potash solutions in terms of COD and TN reduction has been shown. The solutions analysis has also highlighted the improvement of their interfacial properties (surface tension, contact angle). These properties, whose origin was attributed to the accumulation of biosurfactants, confer to potash regenerated solutions a best cleaning power. This point was validated during cleaning assays of organic ultrafiltration membranes fouled by milk proteins. The optimization of solutions formulation has also enabled obtaining a cleaning performance as efficient as those of a commercial detergent largely used for this type of application. Finally, economic and environmental impacts of the potash lyes integration in substitution to soda ones were evaluated for dairy industrial CIP through a techno-economic analysis and a Life Cycle Assessment (LCA)

La régénération des solutions de lavage utilisées en Nettoyage En Place (NEP) présente un intérêt, tant économique qu’environnemental, pour les industriels laitiers. L’étape clé du NEP réside dans le lavage alcalin qui assure l’élimination des souillures organiques déposées sur les équipements. Ce lavage est généralement effectué par des lessives de soude, moins onéreuses que celles de potasse. Nos travaux ont visé à appliquer un procédé physico-chimique de régénération à des lessives de potasse en vue de rentabiliser leur intégration au NEP laitier. La régénération de solutions de potasse souillées par du lait a été examinée et comparée à celle de solutions de soude. L’efficacité du procédé à épurer les solutions de potasse en termes d’abattement de la DCO et de Ntot a été démontrée. L’analyse des solutions régénérées a par ailleurs mis en évidence l’amélioration de leurs propriétés interfaciales (tension superficielle, angle de contact). Ces propriétés, dont l’origine a pu être attribuée à l’accumulation de biotensioactifs, confèrent aux solutions de potasse régénérées un meilleur pouvoir nettoyant. Ce point a été validé lors d’essais de nettoyage de membranes organiques d’ultrafiltration colmatées par des protéines laitières. L’optimisation de la formulation de ces solutions a permis l’obtention de performances de nettoyage comparables à celles d’un détergent commercial classiquement utilisé pour ce type d’application. Enfin, les impacts économiques et environnementaux de l’intégration de lessives de potasse en substitution à celles de soude ont été évalués pour un NEP laitier industriel au travers d’une étude technico-économique et d’une Analyse de Cycle de Vie (ACV)
The regeneration of Cleaning In Place (CIP) solutions is interesting, both economically and environmentally, especially in dairy industry. The CIP’s key step lies on the alkaline washing which ensures the removal of organic contaminants deposited on the equipment. This washing is generally done by soda lyes, less expensive than potash ones. Our work aimed to apply a physicochemical regeneration process, based on adsorption-coagulation-flocculation phenomena, on potash lyes to make their integration in the dairy CIP affordable. The regeneration of potash solutions soiled with milk was examined and compared with the soda solutions regeneration. The process effectiveness to purify potash solutions in terms of COD and TN reduction has been shown. The solutions analysis has also highlighted the improvement of their interfacial properties (surface tension, contact angle). These properties, whose origin was attributed to the accumulation of biosurfactants, confer to potash regenerated solutions a best cleaning power. This point was validated during cleaning assays of organic ultrafiltration membranes fouled by milk proteins. The optimization of solutions formulation has also enabled obtaining a cleaning performance as efficient as those of a commercial detergent largely used for this type of application. Finally, economic and environmental impacts of the potash lyes integration in substitution to soda ones were evaluated for dairy industrial CIP through a techno-economic analysis and a Life Cycle Assessment (LCA)

Este proyecto es el resultado de las experiencias de cuatro estudiantes de la facultad de administración de empresas de la UPC. El rubro va dirigido a los suplementos alimenticios de proteína. En la actualidad el 39% de peruanos practica deporte, y que el consumo per cápita de suplementos es de 112 soles con una proyección a cinco años e incremento de 50%. Es decir, los peruanos invertirán hasta 250 soles mensuales. Asimismo, Lima concentra el 70% de venta de suplementos con tendencia a seguir creciendo. (ARELLANO MARKETING). Muchos creen que los suplementos con los que complementan su dieta, tienen muchos aditivos artificiales, alto índice de grasa, efectos secundarios y un precio elevado. Investigando sobre esa problemática, el Perú es el principal abastecedor de pota del mundo, captura alrededor de medio millón de toneladas al año, no tiene veda, es súper económica, cuenta con gran valor proteico, bajo en calorías con gran variedad de vitaminas y minerales. Por ello, creamos el producto innovador denominado POTA PROTEIN, una proteína en polvo a base de calamar gigante o más conocido como pota. El objetivo de POTA PROTEIN es satisfacer las necesidades de aquellas personas que practican deporte y busquen opciones de suplementos de origen natural, con bajo índice de grasa y a un precio menor en comparación de los suplementos comerciales.
This project is the result of the experiences of four students from the Faculty of Business Administration of the UPC. This heading is aimed at protein food supplements. Currently 39% of Peruvians practice sports, and the per capita consumption of supplements is 112 soles with a projection to five years and an increase of 50%. In other words, Peruvians will invest up to 250 soles a month. Likewise, Lima concentrates 70% of sales of supplements with a tendency to continue growing. (ARELLANO MARKETING). Many believe that supplements that supplement their diet have many artificial additives, high fat content, side effects and a high price. Researching on this problem, Peru is the main supplier of squid in the world, captures about half a million tons per year, has no ban, is super economical, has great protein value, low in calories with a wide variety of vitamins and minerals. That's why we created the innovative product called POTA PROTEIN, a protein powder based on giant squid or better known as squid. The goal of POTA PROTEIN is to meet the needs of those who practice sport and are looking for options of natural supplements, with low fat content and at a lower price compared to commercial supplements.
Trabajo de investigación

La presente investigación nos permite obtener información y determinar cuáles fueron los “Factores claves que influyeron en las exportaciones de Pota cocida congelada desde el puerto de Paita hacia China durante los años 2012 – 2016.” El primer capítulo, detalla los aspectos relevantes del producto, iniciando con la definición de la Pota, ficha técnica, clasificación arancelaria y método de captura. Luego, vemos la evolución de la industria pesquera, las exportaciones de Pota y el análisis de los factores claves en las exportaciones. Se investiga los fenómenos ambientales y sus efectos frente a la Pota. Asimismo, indagamos temas legales relacionados a la Pota, zona de pesca, puerto de Paita y la informalidad pesquera. Finalmente, se considera el mercado de Asia y China, Tendencia de consumidor y TLC. El segundo capítulo, muestra el planteamiento para la investigación, el proceso, experiencias mediante entrevistas realizadas para la recolección de datos. Por otra parte, el tercer capítulo se analiza los datos y resultados de las entrevistas por segmento y categoría, relacionando con la información investigada que nos permite obtener un panorama claro del problema. Finalmente, el cuarto capítulo se elabora con la finalidad hacer un cruce de información sobre los resultados obtenidos en las entrevistas y la información investigada en el marco teórico. Asimismo, se logra identificar hallazgos, limitaciones, brechas y barreras presentadas en el proceso de la investigación, para luego concluir si se logró alcanzar los objetivos planteados inicialmente.
The following investigation allow us to obtain information and determine the “key factors that may have influenced the exports of frozen cooked giant squid from the port of Paita to China, during year 2012 until 2016”. The first chapter, we detail the relevant and related aspects to the product. We start with the definition of giant squid, technical sheet, tariff classification and fishing method. Second, we explain the evolution of the fishing industry, exports of giant squid and the analysis of the key factors of exports. We investigate the environmental phenomenal and their effect in relation to giant squid. Additionally, we take an interest in legal matters related to giant squid; fishing area, port of Paita and fishing informality. Finally, we consider the Asian and Chinese market and consumers trends. On the second chapter, we show the approach for the investigation, the process performed and the experiences obtained from interviews for data collection. On the third chapter, we analyze the data and results from the interviews, performed by segment and category. We compare this data with the information obtained from our investigation and could get a clear picture about the posed problem to help us with our study. Finally, the forth chapter is made in order to do an information crossing between the data obtained from the interviews and from the information researched on the theoretical framework. Additionally, we achieve to identify findings, limitations, gaps and barriers during the investigation process. Then we will conclude if we were able to fulfil the initially proposed objectives.
Tesis

En la región Piura se desarrolla una de las actividades extractivas pesqueras más importantes del Perú, siendo Paita el distrito con mayor desembarque. Según el Instituto del Mar del Perú (IMARPE), durante el periodo 2016-2017, se desembarcó el 57.4% de la pota extraída a nivel nacional en el distrito de Paita. La Dirección Regional de Producción de Piura (DIREPRO Piura), en las implicancias del proceso extractivo, es la entidad estatal encargada de impulsar, controlar y gestionar a los diferentes grupos de interés involucrados. La presente investigación realizó un análisis de la experiencia de la DIREPRO en relación a su rol como gestor y articulador de los grupos de interés en la extracción de pota en el distrito de Paita. Para ello, se identificó a cada involucrado en el eslabón de la cadena productiva en la que se desenvuelve, y se evaluó su relación con la DIREPRO utilizando el enfoque de redes para medir la articulación de la cadena productiva, así como el nivel de intermediación del gobierno regional. Para la sistematización de la información, se utilizó la herramienta WebQDA, y Gephi, para la visualización de la red. Mediante el análisis de los grupos de interés en la cadena productiva de la pota, se obtuvieron los siguientes resultados: la densidad (vinculación) de la red es de 40.1%, lo cual implica que existen todavía relaciones por explotar; además, se obtuvo que el grado de intermediación y centralidad de la DIREPRO Piura son altos, aunque, el grado de legitimidad aún es bajo. Las acciones que la DIREPRO Piura realice en torno a la cadena productiva de la pota deben de ser bien vistas por los actores, puesto que este es el órgano que debe fomentar la articulación de los grupos de interés para la sostenibilidad de la cadena productiva de la pota.
Tesis

Face au réchauffement climatique et à la forte consommation énergétique du secteur du bâtiment, l'utilisation de matériaux à faible empreinte écologique et recyclables issus de sources biologiques représente une solution prometteuse pour atténuer ce problème.L'objectif de cette thèse est d’explorer les performances hygrothermiques à l'échelle du bâtiment d'un nouveau matériau bio-sourcé à base de pulpe de betterave et d'amidon de pomme de terre, avec un rapport massique égale à 0.4, préalablement élaboré, caractérisé et optimisé dans des études antérieures à l'échelle du matériau.Au début de cette étude, une investigation expérimentale approfondie a été entreprise sur la microstructure du matériau, ainsi que sur la cinétique de séchage et les performances mécaniques des deux types de briques (pleines et perforées). Il a été observé une performance supérieure des briques perforées par rapport aux briques pleines. Ensuite, l'étude a été approfondie par une analyse analytique, numérique et expérimentale des performances thermiques des briques perforées. Les résultats obtenus ont montré une bonne concordance entre les trois analyses réalisées.Finalement, l'analyse des propriétés hygrothermiques du bio-composite étudié a été réalisée à l'échelle du bâtiment. Les performances énergétiques globales, le contenu total en eau, le taux de séchage, le risque de condensation, le comportement thermique dynamique, ainsi que l'analyse du risque de croissance de moisissures pour quatre configurations d'isolation différentes ont été évalués numériquement dans deux conditions climatiques distinctes en France. Cette étude nous a permis de déterminer son adaptabilité à diverses conditions climatiques
In the face of climate change and the high energy consumption of the building sector, the use of low-impact and recyclable materials derived from biological sources represents a promising solution to mitigate this issue.The aim of this thesis is to explore the hygrothermal performance at the building scale of a new bio-sourced material based on beet pulp and potato starch, with a mass ratio of 0.4, previously developed, characterized, and optimized in previous studies at the material scale.At the beginning of this study, an in-depth experimental investigation was conducted on the material's microstructure, as well as on the drying kinetics and mechanical performance of the two types of bricks (solid and perforated). A superior performance of the perforated bricks compared to the solid bricks was observed. Subsequently, the study was furthered by an analytical, numerical, and experimental analysis of the thermal performance of the perforated bricks. The results showed good agreement between the three analyses conducted.Finally, the analysis of the hygrothermal properties of the studied bio-composite was carried out at the building scale. The overall energy performance, total water content, drying rate, condensation risk, dynamic thermal behavior, as well as the analysis of mold growth risk for four different insulation configurations were numerically evaluated in two distinct climatic conditions in France. This study enabled us to determine its adaptability to various climatic conditions

碩士
國立臺灣大學
農業經濟學研究所
106
Sweet potato is the main grain crops in Taiwan in the early time. It also has many advantages such as easy cultivation, high yield per hectare area, and rich nutrition. In recent years, with the income rise and the concept of health promoting, the utilization of sweet potato has been transformed into consumption oriented. This study uses in-depth interview to collect information and opinions. To explore the development of sweet potato industry in Taiwan, production and marketing of sweet potato, commodity value and marketing channels have been analyzed to estimate the profitability of farmers and agribusiness enterprises in fresh and processed products (including sweet potato skins). It was found that the total farm revenue from sweet potato sales was NT$355,235 per hectare in 2016 with the gross revenue of NT$254,266, and the gross profit margin of 71.58%. If the sweet potato were processed by agribusiness enterprises into roasted products, the gross profit margin would be 59.49%. If the sweet potato were processed into sweet potato fries, the gross margin would be reduced to 47%. If the sweet potato skins was processed by biotechnology enterprises into biotech nutrition products, the gross profit margin would be 58.6%. To summarise, this study indicates that the development of sweet potato industry in Taiwan is full of market opportunities. We that the introduction of biotechnology is an important way to create the new processing and utilization of sweet potato by-products. To enhance the competitiveness of sweet potato industry in Taiwan, we must strengthen the commercialization of biotechnology, establish spcilized marketing channel and brand marketing, as well as maximize the value-added of product lines. In this way, it can promote the vigorous development of sweet potato industry and bring in new opportunities for agriculture in Taiwan. Keywords: Sweet potato, Sweet potato skin, In-depth

This study relates market reforms to agricultural trade performance, in particular the export performance of South Africa’s potato industry. The market reform considered here is the deregulation of South Africa’s potato market. Changes in producer prices and volumes of exports and imports are the most important outflows of deregulation that the study focuses upon. In the first part, this study provides an overview of deregulation in the potato industry. The objective of this study is to analyse the impact of deregulation on the competitiveness and the level of integration of the South African potato industry in relation to potato markets in the SADC region. Competitiveness is perhaps the most fundamental idea in economics. Agricultural industries often fight to protect or increase their market share both domestically and internationally. The method used here to measure competitiveness is the Revealed Trade Advantage (RTA), a measure based on the share of a country’s net trade in a specific commodity relative to its total international trade. The impacts are investigated individually for the three sub-categories of potatoes: fresh/table, processed and seed. Comparisons are made between South Africa and selected countries in the Southern African region. Basic trend analysis illustrates that domestic potato production has increased significantly over the past decade. Exports as a percentage share of production have increased consistently from the late nineties to reach 8% of domestic production by 2003. However, from 2004 onwards exports have decreased as the domestic informal market for fresh potatoes expanded at a tremendous pace. The results of the Real Trade Advantage (RTA) analysis reveal that South Africa’s potato (fresh) exports are the most competitive in the SADC region. Yet, the competitiveness of the potato supply chain in South Africa was found to be marginal as far as regional competitiveness is concerned. Thus, the potato supply chain exhibits a negative trend in competitiveness when moving from the primary to the processed product. Another approach to gain a better understanding of the possible impact of deregulation on agricultural markets is to analyse the extent to which domestic commodity markets respond to changes in international prices. Hence, the level of price transmission between local and foreign markets can be analysed. The analysis consists of a set of econometric applications. Annual producer prices of various trading nations are analyzed by testing mostly for the existence of long run equilibrium between the price series of the various nations and the dynamics of the relation between the prices and their causality. The results of the price transmission analyses show that the South African potato market is not well integrated with other regional potato markets, despite some trade occurring. This can partly be explained by the fact that over the past decade on average only 6 percent of all potatoes in the local market were exported into the region. Further more one has to take the tradability of the good into consideration when analysing the level of price transmission and, therefore, the level of integration of markets, In other words; can the good be traded or not? Potatoes (fresh) are perishable and bulky and therefore not easy to transport. Export trade in fresh potatoes involves high transport and transaction costs which complicate the process of price transmission across markets. Even in the exceptional cases (Mozambique and Mauritius) where market integration was detected, price transmission was found to occur from South Africa to these countries and not vice versa. Hence, from the empirical evidence of this study it seems as if domestic prices are determined by domestic supply and demand dynamics and regional exports do not influence the formation of prices in the domestic market. Although the liberalization of the South African potato market has led to the lowering of tariffs and non-tariff trade barriers, only weak evidence was found that there is some level of market integration between South Africa and its main trading partners in the SADC region. Copyright
Dissertation (MScAgric)--University of Pretoria, 2010.
Agricultural Economics, Extension and Rural Development
unrestricted

碩士
國立臺灣大學
農業經濟學研究所
99
The main purpose of the study is to investigate the production and marketing of sweet potatoes produced in Shuiling, Yunlin county. The statistics related to production and marketing are collected through face-to-face interview. The economic analysis is then conducted based on these primary data. The research results are as the follows. From the aspect of production, we found that the average production cost of sweet potatoes farmers in Shuiling area is 180,958 NT$/ha, in which the direct and indirect production costs are 144.558 NT$/ha(79.88%) and 36,400NT$/ha(20.12%), respectively. The optimal planted area to the crop is 5-10 hectare because it gets the highest profit for each hectare. Our findings also suggest that the supply elasticity of sweet potatoes in Shuiling area is 0.3207. 76.33% of the products produced were sold to middlemen; 15.56% of them were sold directly to consumers; and 7.78% of them went to retail markets. There different production-marketing patterns for the sweet potatoes farmers in Shuiling. The farmers who are producers as well as middlemen often get higher profitability. Meanwhile, they are facing higher uncertainty as well. same time. Besides, farmers are getting higher returns if they are able to sell the products to consumers directly.

The introduction of democracy in country of post-Apartheid South Africa precipitated both economic and social changes. These changes have led to the liberalisation of the economy and the movement of the agricultural sector from being highly regulated to a market-based sector. Consequently, the country‟s economy has become exposed to global uncertainties. These changes brought about the need for role players to understand the dynamics of the agricultural sector in order to forecast possible future trends and assess their impact on agricultural production and consumption. Projecting economic and environmental uncertainties in agriculture is essential to make informed decisions and sustain agribusinesses. In an attempt to combat the challenges and to understand the dynamics mentioned above, a system of equations with the ability to simulate the dynamic interaction between production and consumption at a regional level for South African potato producers, policy makers and wholesalers, is developed in this study. Existing methodology on partial equilibrium modelling is applied to develop a tool that can be used to analyse the potential impact of relative environmental shifts on the South African potato industry. Individual equations, which are | vi collapsed into a single system of equations, are estimated by means of Ordinary Least Square (OLS). The specific objectives of this study are as follows:

• To estimate the potato area planted, yield and consumption of various categories of potatoes, in order to determine the price elasticity of demand and elasticity of supply.
• To develop a system of equations that will be used to generate baseline projections of demand and supply in the industry.
• To undertake impact analysis of various scenarios over the period 2011 to 2015. Although the model developed is mainly South African focusing on regional production and national consumption, the dissertation will recommend the possibility of future studies that use this study as a springboard for further research. These recommended studies include the linking of other models to improve and simulate relations between the potato sector and other sectors, thereby emulating the actual economy.
• One such requirement is to connect the vegetable and potato industries, a move which agricultural sector experts believe will benefit the outcomes of the potato industry.

Consumption is estimated at national level, and is conducted according to the use of informal fresh and formal fresh potatoes for processing and seed potatoes. It is advisable for future research and study to estimate and project production and consumption at regional level. The baseline projection will be developed, and then the study will further undertake several scenarios which will lead to various possible future outcomes, discusses and document the response. Eventually, the model shows possible relationships, uncertainties and interactions between potato productions, consumption and prices. And that the domestic price, quantity demanded, the supply and the net exports actually determine the South African market equilibrium price and the decision to export in the South African potato industry. This is also called the near autarky situation. Copyright
Dissertation (MSc(Agric))--University of Pretoria, 2012.
Agricultural Economics, Extension and Rural Development
unrestricted

Physicochemical properties of flours and starches isolated from tubers and roots commercially available in Australia and traditionally produced in Indonesia were investigated in this study. The results showed that these flours and starches may be utilized in certain food applications. Raw starchy materials from Australia included taro, yam, and sweet potato. Due to its narrow particle size distribution (1-64 μm), taro flour would be better suited in applications which require improved binding and reduced breakability. The paste of sweet potato flour and starch had higher clarity compared to those of yam and taro. All flours and starches showed variable pasting behavior. In general, all starch samples had higher viscosity than that of flour samples. Taro flour had the highest viscosity among other flour samples. Yam flour and starch were more stable against heat and mechanical treatments. An apparent shear thinning behavior was observed from the extracted mucilage. Concentration dependant flow behavior of all mucilage samples was successfully fitted by the (Ostwald) Power Law, Hershel Buckley, and Casson models. Meanwhile, flours and starches isolated from tubers and roots grown in Indonesia also had properties suitable for certain food applications. Compared to other flour samples, cassava and canna flours contained the highest amount of total starch (TS). Taro starch had the lowest amount of TS among other starch samples with 75.44%. The highest amount of amylose was observed from yam and canna flours (25.24 and 23.19%, respectively). Among starch samples, canna starch contained the highest amylose content (30.38%), while taro had the lowest (7.64%). In terms of protein content, arrowroot flour had the highest amount (7.70%), in contrast to cassava flour which had the lowest (1.51%). Compared to other flours, canna and konjac flour were the most slowly digested which indicated by their high amount of resistant starch (RS). Canna starch had the highest swelling power and viscosity than other starches and flours. The clearest paste was observed from cassava flour and starch as opposed to konjac starch which was the most opaque paste. Subsequently, physicochemical properties of composite flours made of wheat flours at different protein contents (low and high protein contents) and canna or konjac flours at different level substitution (0, 25, 50, 75, and 100%) were prepared and analyzed. Compared to that of wheat flour alone, the increasing level of canna flour from 0-100% significantly increased the amount of RS but decreased protein content of wheat-canna composite flours. This substitution did not alter the TS, amylose, and amylopectin contents of these mixtures. Changes of physicochemical properties were also observed in wheat-konjac composite flours. The increasing amount of konjac flour decreased the TS, amylose, amylopectin, and protein content of the mixtures. Substitution of wheat flour with 75% of canna or konjac flours in HPWC (High Protein Wheat-Canna), HPWK (High Protein Wheat-Konjac), and LPWK (Low Protein Wheat-Konjac) increased the swelling power of these mixtures at 80 and 90◦C. In general, substitution of wheat flour with up to 50% of canna or konjac flours significantly decreased viscosity of composite flours. Further increase of canna or konjac flours did not cause any other observable decline. In addition, the substitution of wheat flour with canna or konjac flours increased the gelatinization temperature of all composite flours.

A net shift analysis was used to analyze growth in employment and value added from 1954 to 1982 in SIC 2037, Frozen Fruits, Fruit Juices, and Vegetables. This analysis indicated that the Pacific Northwest dominated the growth experienced in this sector over this time period. Oregon's share of total U.S. employment in SIC 2037 increased from 7.3 percent in 1954 to 16.1 percent in 1982. Value added in Oregon was 16.1 percent of the U.S. total in 1982, and growth in both employment and value added was at a greater rate than the overall U.S. rate of growth in this sector. Washington's share of employment increased from 10.3 percent to 13 percent, and the share of U.S. total value added in this sector grew from 11 percent to 14.2 percent. Value added by the freezing of fruits and vegetables in Idaho increased to 10.3 percent of the U.S. total in 1982, and employment grew to a share of 10.5 percent, from 3.5 percent in 1954. An informal survey of executives in six food processing plants in Oregon suggested that expanding international export markets was essential to continued growth for this industry in the Pacific Northwest. A model of Japan's import demand of frozen vegetable products, specifically corn and potatoes, is estimated using data from 1978 through 1986 of real own price at the export site, Japanese consumer expenditures adjusted by Japan's CPI, and Japan's domestic production of frozen corn and potatoes. Commerce Department data on exports by Customs District was used to disaggregate import demand by region; namely Oregon, Washington, the two together as Pacific Northwest, and the total U.S. It was found that the demand for frozen corn imports is more responsive to changes in real own price than the import demand for frozen potatoes. Income elasticities were positive and higher for frozen potato import demand than for frozen corn demand, except for Oregon originating exports. Production in Japan of frozen corn has a higher negative impact on exports from Oregon ports than Washington based exports. Production of frozen potatoes in Japan did not have a negative impact on import demand from any of the four export sites.
Graduation date: 1989