The importance of European honey bees in improving fruit set, yield and fruit weight of kiwifruit on the central east coast of Australia was investigated. Field investigations were carried out using different bee saturations and different types of male pollen parents. These investigations confirmed the importance of honey bees in kiwifruit fruit set, yield and fruit weight. However, the results suggested that increasing bee activity alone may not increase pollination of kiwifruit by honey bees. Many factors need to be understood before introducing bees into the orchard. Bees were more effective during the early part of the flowering period, and bee activity varied according to the sex of the vine, planting design and the time of day. The type of male pollen parents also influenced fruit size and quality. Flowers pollinated by different pollen parents were assessed for pollen tube growth and histochemical changes. The resulting fruit were also examined for weight and seed numbers. Honey bees play the major role in the size and yield of kiwifruit, but the design of male vines, their age and type of male pollen may also contribute. The kiwifruit pistil also possesses important features that can be considered as adaptations to insect pollination. / Doctor of Philosophy (PhD)

Thesis (MScAgric)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (MScFoodSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Postharvest fruit loss is a major challenge in addressing food security, sustainable management of resources and profitability of agribusiness. The incidence of postharvest loss and changes in physico-chemical properties of three types of fruit (peaches, pears and oranges) were evaluated at retail and during post-purchase storage. The amount of physical loss at the three retail outlets studied ranged from 3.61% to 18.09% among the fruit types, with the highest incidence occurring in peaches. The estimated annual national physical loss at retail was 418 tons for pears, 1000 tons for oranges, and 7 240 tons for peaches. Based on the WHO recommended 146 kg per capita per year consumption of fruit, the total loss of the three types of fruit was sufficient to meet the dietary fruit requirements of 50 000 people per annum. Similarly, based on the recommended daily allowance of 50 mg of ascorbic acid, these losses could meet the annual vitamin C needs of 82 000 people. The estimated monetary value of the losses at retail ranged from R2.2 million to R96.87 million per annum depending on fruit type and retail outlet. The land wasted to produce lost fruits was 1965 ha while energy wasted was 32.77 x 106 MJ. Greenhouse gas emission of the losses was 2870 tons CO2eq and total water footprint 68 0000 m3. Losses were mainly due to the presence of severe physical damage, rots and physiological disorders. There were significant variations in physico-chemical properties of fruit of the same type from different retail outlet. Although ambient temperature storage improved fruit colour and some chemical constituents responsible for palatability, it was associated with high physical and nutritional (vitamin C) losses. Results from this study show that appropriate harvesting maturity, packaging and maximum care in fruit handling is essential in reducing postharvest losses. Efficient cold chain management and fruit inspection for rots and damages could help to reduce subsequent spoilage at retail and during post-purchase storage. Given that the incidence of postharvest fruit loss observed at retail is the result of cumulative effects along the supply chain, further studies are warranted to map fruit history and magnitude of losses along the value chain. / AFRIKAANSE OPSOMMING: Naoesvrugteverlies is ‟n groot uitdaging in die strewe na voedselsekerheid, volhoubare hulpbronbestuur en winsgewende landbousake. Die voorkoms van naoesverlies sowel as fisiko-chemiese naoesveranderinge by drie vrugtesoorte (perskes, pere en lemoene) is gevolglik by kleinhandelsafsetpunte én gedurende berging ná aankoop beoordeel. Die graad van fisiese verlies by die drie betrokke kleinhandelspunte het gewissel van 3,61% tot 18,09% tussen die vrugtesoorte, met die hoogste verlies by perskes. Die geraamde jaarlikse nasionale fisiese verlies by die kleinhandelspunte was 418 ton pere, 1 000 ton lemoene en 7 240 ton perskes. Op grond van die Wêreldgesondheidsorganisasie se aanbevole jaarlikse vrugte-inname van 146 kg per persoon, was die totale verlies van die drie vrugtesoorte genoeg om aan die vrugtedieetvereistes van 50 000 mense per jaar te voldoen. Op grond van die aanbevole daaglikse inname van 50 mg askorbiensuur, kan hierdie verlies eweneens in die jaarlikse vitamien C-behoeftes van 82 000 mense voorsien. Die geraamde geldwaarde van die verlies by die kleinhandelspunte strek van R2,2 miljoen tot R96,87 miljoen per jaar, na gelang van die vrugtesoort en bepaalde kleinhandelspunt. Die vermorste grond om die verlore vrugte te produseer, was 1 965 ha, terwyl energievermorsing op 32,77 x 106 MJ te staan gekom het. Kweekhuisgasvrystellings met betrekking tot die verlies was 2 870 ton CO2e, en die totale watervoetspoor 68 0000 m3. Vrugteverlies kon hoofsaaklik aan ernstige fisiese skade, verrotting en fisiologiese afwykings toegeskryf word. Daar was beduidende variasies in die fisiko-chemiese eienskappe van dieselfde vrugtesoort by verskillende kleinhandelaars. Hoewel berging by omgewingstemperatuur vrugtekleur en bepaalde chemiese komponente vir smaaklikheid verbeter, word dit ook met groot fisiese en voedingstof- (vitamien C-) verliese verbind. Die resultate van hierdie studie toon dat toepaslike oesrypheid, die regte verpakking en maksimum sorg in vrugtehantering noodsaaklik is om naoesverlies te verminder. Doeltreffende koelkettingbestuur en vrugte-inspeksie vir verrotting en skade kan latere bederf by kleinhandelsafsetpunte sowel as gedurende berging ná aankoop help beperk. Aangesien die naoesvrugteverlies wat by die kleinhandelspunte waargeneem is uit kumulatiewe faktore in die verskaffingsketting spruit, is verdere studies nodig om vrugtegeskiedenis na te spoor en die omvang van die verlies in die algehele waardeketting te bepaal.

Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Producing fruit of the appropriate size and high quality is of the upmost importance to realize a profit in the fruit industry. This can be achieved through bloom or fruitlet thinning to reduce the number of fruit left on the tree. The cost of production is rising and labour cost forms a large part of the total production cost. Thinning of stone fruit is labour intensive and expensive, so an alternative to hand thinning needs to be found. Two alternatives are chemical and mechanical thinning. Chemical thinners are not routinely used in stone fruit as it is in pome fruit production and gibberellins were evaluated in this study. The Darwin 300TM was evaluated as a mechanical alternative to hand thinning. It thins flowers during bloom, before fruitlet thinning by hand is performed. In our trials on nectarines and Japanese plums the objective of reducing the time required for hand thinning was achieved, with the Darwin 300TM reducing the time required by up to 50%. When the time required to thin was reduced too much it also reduced the yield, but this could be overcome by lowering the rotor speed or using different strategies during supplementary hand thinning at the fruitlet stage. The bloom thinning and reduction in yield led to an increase in the fruit size. Care should be taken when using the Darwin 300TM as the earlier thinning could increase pit splitting and/or fruit cracking, especially in cultivars that are sensitive to these defects. The optimal rate of thinning needs to be determined for each cultivar individually. The application of gibberellic acid (GA3) and gibberellin A4+7 (GA4+7) at the pit hardening stage in the previous season could decrease the number of flowers for the following growing season. There was no effect on the yield at harvest or fruit size in the season of GA3 and GA4+7 applications, but the fruit firmness was increased. This effect was more pronounced for the GA4+7 applications. Our objective of reducing the time required for thinning was achieved in some but not all cultivars. The yield was not significantly reduced, with the fruit maturity only delayed in ‘African Rose’ plum. Again no increase in fruit size was found, but the fruit firmness was again increased. The GA-applications therefore were not satisfactory in their reduction of the time required for hand thinning. A positive effect is the increase in fruit firmness, which could possibly increase the storage potential of the fruit without having negative effects on the other aspects of fruit quality but this needs further evaluation. / AFRIKAANSE OPSOMMING: Produksie van vrugte met die verlangde vruggrootte en hoë vrug kwaliteit is baie belangrik vir die realisering van ‘n wins in die vrugte-industrie. Met hierdie mikpunt in gedagte, is blom- en vruguitdunning baie belangrik om die aantal vrugte per boom te verminder. Die kostes geassosieer met vrugte produksie is besig om te styg en arbeidskoste vorm ‘n groot deel van die totale produksiekostes. Uitdunning van steenvrugte is arbeidsintensief en baie duur, dus moet ‘n alternatief vir handuitdunning gevind word. Daar is twee alternatiewe naamlik chemiese en meganiese uitdunning. Chemiese uitdunmiddels word algemeen in kernvrugproduksie gebruik, maar daar is tans geen chemiese middels vir steenvrugte nie. In hierdie studie was gibberelliene ge-evalueer as potensiële uitdunmiddel. Die Darwin 300TM is ge-evalueer gedurende blomtyd as ‘n meganiese alternatief vir handuitdunning. Die masjien verwyder blomme en verminder so die vruguitdunning benodig. In ons eksperimente op nektarien- en Japanese pruimkultivars het ons gevind dat die tyd benodig vir handuitdunning met tot 50% verminder is deur die Darwin 300TM. Dit het ook daartoe gelei dat die totale oes per boom verlaag is. Hierdie effek kan vermy word deur die rotor spoed te verminder of die strategie vir aanvullende handuitdunning aan te pas. Die feit dat die grootste deel van die uitdunproses in blomtyd uitgevoer is en ook die feit dat die totale oes per boom verlaag is, het daartoe gelei dat die vrugte groter was. Die vroeër uitdunning met die Darwin 300TM kan egter lei tot ‘n verhoging in vrugkrake en gesplete pitte. Dit moet veral in gedagte gehou word by kultivars wat geneig is tot hierdie afwykings/defekte. Die optimum tempo van uitdunning moet vir elke kultivar individueel bepaal word. Wanneer gibberelliensuur (GA3) of gibberelien A4+7 (GA4+7) by pitverharding toegedien word in die vorige groeiseisoen, kan dit lei tot die vermindering van die hoeveelheid vrugte in die volgende seisoen. Daar was geen effek op die totale oes per boom en die vruggrootte tydens oes in die seisoen van aanwending nie, maar die vrugfermheid is verhoog. Die effek was hoër na die GA4+7 as na die GA3 aanwending. Die mikpunt om die tyd benodig vir handuitdunning te verminder, is in sommige kultivars bereik. Die oes per boom in die opvolgseisoen is weer eens nie verlaag nie, maar die vrug rypheid van ‘African Rose’ pruime is vertraag. Geen effek is op die vruggrootte opgemerk nie, maar die vrugfermheid was weer eens verhoog. Die GA-toedienings het dus nie bevredigend die tyd benodig vir handuitdunning verminder nie. ‘n Positiewe effek is die verhoging van die vrugfermheid, wat moontlik kan lei tot die verhoging van die opbergingspotensiaal van die vrugte sonder enige ander negatiewe effekte, maar hierdie aspek benodig verdere navorsing.

The present study was undertaken to compare the ascorbic acid content of canned and frozen fruits before and after preparation for quantity use.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20447号 / 農博第2232号 / 新制||農||1050(附属図書館) / 学位論文||H29||N5068(農学部図書室) / 京都大学大学院農学研究科農学専攻 / (主査)教授 北島 宣, 教授 田尾 龍太郎, 教授 土井 元章 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Thesis (Ph.D. (Plant Production)) -- University of Limpopo, 2022 / In 'Hass' avocado fruit, pre-harvest and postharvest factors affecting exocarp colour change during ripening are vital to maintain the industry’s credibility, competitiveness and profitability. Currently, the South African ‘Hass’ avocado fruit exocarp colour development is affected by pre- and postharvest factors, ultimately, fruit does not develop the required purple colour during ripening. These pre- and postharvest factors must be understood in order to implement strategies that avoid downgrading of South African 'Hass' avocado fruit by lucrative markets due to insufficient purple colour development during ripening. In 'Hass' avocado fruit, exocarp colour development is associated with an increase in anthocyanin synthesis and accumulation during ripening. However, limited information is available regarding factors regulating anthocyanin synthesis and accumulation in 'Hass' avocado fruit during ripening. Therefore, the overall aims of this study were to investigate pre-harvest practices and postharvest treatment that increase exocarp anthocyanin synthesis during ripening. In addition, determine whether exocarp glucose and other antioxidants contribute to 'Hass' avocado fruit exocarp colour development during ripening. In chapter 3, the study looked at how crop load adjustment affects ‘Hass’ avocado fruit exocarp colour development during ripening at three different harvest maturities. The crop load adjustment treatments were applied as: high (100%), moderate (50%) and low (25%) at three harvest times (early, mid- and late). After harvest, fruit were stored at 5.5°C for 28 days, thereafter, ripened at 25°C. The experimental design was carried out as 3 x 3 factorial, arranged in a completely randomized design (CRD) with three replications. The results showed that total anthocyanin and cyanidin 3-O-glucoside concentrations of ‘Hass’ avocados increased following crop load adjustment from normal (100%) to moderate (50%) and low (25%) loads, resulting in improved exocarp colour development during ripening. Furthermore, we discovered that fruit harvested from moderate (50%) and low (25%) crop loads accumulated higher exocarp sugars (D-mannoheptulose and perseitol) at three harvest maturities when compared with high crop load (100%). Moreover, total phenolic concentration of fruit harvested from moderate (50%) and low (25%) crop loads was higher than that obtained from high load fruits, irrespective of harvest maturities. In chapter 4, the study examined the interaction between branch girdling and harvest maturation on the development of 'Hass' avocado fruit exocarp colour during ripening. The experimental design was carried out as 2 x 2 factorial, arranged in a completely randomized design (CRD). The results showed that fruit harvested from girdled trees had poor exocarp colour development as compared to fruit harvested from control trees, regardless of harvest time. Fruit harvested from girdled and ungirdled avocado trees did not show significant differences in visual exocarp colour during early and mid-maturity. Apart from crop load adjustment and girdling as pre-harvest methods to manipulate postharvest exocarp colour, glucose was also infused through the pedicel. Studies on the effect of glucose infusion through the pedicel on the exocarp colour of the ‘Hass’ avocado fruit during ripening were presented in chapter 5. The study included five treatments; control fruit with pedicel and infused with distilled water and glucose concentrations (0.05, 0.13 and 0.28 mM). The distilled water, glucose infused and control fruit were stored at 5.5°C for up to 28 days. After cold storage, fruit were kept at ambient temperature 25°C for ripening. The experiment was conducted as a completely randomized design (CRD) with three replications per treatment. The results showed that glucose infusion through the pedicel markedly increased anthocyanin and cyanidin 3-O-glucoside concentration during ripening. Interestingly, glucose concentrations (0.05 and 0.13 mM) resulted in purple colour development after 8 days at 25°C when compared with control, distilled water and highest concentration (0.28 mM). In chapter 6, the relationship between 'Hass' avocado fruit size, exocarp colour and related pigments with antioxidants capacity and sugar concentration during ripening were investigated. The fruit were categorized by their weight; small (< 200 g) and large (> 201 g). Their diameter and length were also measured using a vernier calliper. Fruit ware stored at 5.5°C for 28 days, then ripened at 25°C. The experimental design was carried out as a completely randomised design (CRD), using 25 fruit replications per category. The results showed that small-sized fruit developed the desirable purple to black exocarp colour when compared with large-sized fruit. Additionally, the results showed that small-sized fruit had higher antioxidant capacity as measured by 2,2 diphenyl 1 picrylhydrazyl (DPPH), ascorbic acid and flavonoid content during ripening when compared with large-sized fruit. Furthermore, it was found that small-sized fruit accumulated higher exocarp and seeds (D-mannoheptulose, perseitol, sucrose and glucose) sugar concentration. We demonstrated and concluded that exocarp colour, pigments, antioxidants and sugar concentration are closely related to size in 'Hass' avocado fruit. Knowledge from this thesis contributes toward the understanding of pre and postharvest factors that may influence colour development of ‘Hass’ avocado fruit during ripening. This study contributes towards bridging the gap in the literature on the biochemical changes associated with colour development of ‘Hass’ avocado fruit during ripening / Agricultural Research Council-Tropical and Subtropical Crops (ARC-TSC) and National Research Foundation (NRF)

Thesis (M.Tech.: Food Technology)-Dept of Biotechnology, Durban University of Technology, 2007 xvi, 106 leaves / Alicyclobacillus acidoterrestris is a spore-forming spoilage micro-organism found in fruit juices whose spores are not destroyed by typical pasteurisation. Once its spores outgrow and multiply in finished juice products, they produce two volatile taint compounds namely guaiacol and 2,6-dibromophenol. In the food industry margins for errors are small and monitoring of products to avert such errors is crucial. Conventional microbiological monitoring is one such technique for spoilage micro-organisms another being automated systems which can detect taints. Both these categories were evaluated in this study with the electronic nose and gas chromatograph being the specific automated systems being assessed. Sensory evaluation was also assessed as a diagnostic tool in the detection of taints. Isolation and identification of what was thought to be A. acidoterrestris was a laborious and expensive exercise which eventually proved inconclusive. A pure culture was purchased and juices were then inoculated with two levels of A. acidoterrestris spores and incubated. Juices from each level of inoculation were evaluated at different time intervals via the above-mentioned monitoring techniques. Of the three media assessed in the microbiological method, Bacillus acidoterrestris medium (BAM) was found to be the most effective for enumerating A. acidoterrestris followed by K-medium (KM) then Orange Serum Agar (OSA). While BAM was still indicating the presence of A. acidoterrestris KM and OSA were not (counts of <10cfu/g). This illustrated that this micro-organism could be easily overlooked if KM or OSA were being used to enumerate them. Considering that many workers actually do use KM and OSA as their media of choice in enumerating A. acidoterrestris (perhaps because BAM is very tedious to prepare) the cause for concern is a real one. Assessment of the resultant taints via sensory evaluation after inoculation and incubation reveals the inability of many panellists to detect taints at levels (as assessed by GC) far above their documented threshold values. While GC is an extremely useful and powerful tool, the level of expertise and skill required to use such an instrument cannot be overlooked nor can the expense involved. With regard to the electronic nose assessment for the presence of the volatile taint compounds, an important finding was that the electronic nose indicated significant differences between test and control samples when panellists performing sensory evaluation did not. This also correlated to an interval when enumeration on OSA illustrated no A. acidoterrestris after several days of inoculation and incubation and BAM and KM did. Without implying that the electronic nose has no drawbacks, it has proved, in this instance to be a simple and easy piece of equipment to use. It can be used to detect taints produced under simulated spoilage conditions at reduced analysis times, levels of expertise, cost and energy.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Green mould is a major citrus postharvest disease caused by a wound pathogen called Penicillium digitatum. Imazalil (IMZ) is the most important postharvest fungicide that is currently registered against green mould and blue mould, given its good protective and curative control and sporulation inhibition. Imazalil can be applied in drench, dip, spray and wax coating applications. Wax coatings improve the quality of the fruit during shelf life by limiting moisture loss and providing a shiny appearance. The primary objective of this study was to investigate the application of imazalil in wax coatings in citrus packhouses to control green mould and preserve fruit quality. The first aim of this study was to evaluate the protective and curative control and sporulation inhibition of IMZ sensitive and resistant isolates of P. digitatum following single IMZ application in wax coating and IMZ application in aqueous dip as well as wax coating. For single application, Valencia orange fruit was curatively or protectively treated with a carnauba-based coating into which IMZ at 3000 μg.mL-1 was mixed. For curative treatments, fruit was treated after 24 hour's incubation. Coating was applied at 0.6, 1.2 and 1.8 L.ton-1 of fruit on a commercial coating applicator. Untreated control and fruit treated with coating only showed up to 80% infection for both sensitive and resistant isolates. Imazalil in coating proved to have better protective than curative action against the sensitive isolate, while control of the resistant isolate was poor. Imazalil residue levels increased with increasing coating load (0.85 to 1.75 μg.g-1). For double application, clementine, satsuma, navel and Valencia orange fruit were used. Curative and protective control following dip only treatment (IMZ sulphate at 500 μg.mL-1 for 45 s and 90 s) was compared with coating only treatment (IMZ at 3000 μg.mL-1 at 1.8 L.ton-1), and double application comprising dip (45 s in IMZ sulphate at 500 μg.mL-1) followed by 2000 μg.mL-1 IMZ in coating at 0.6, 1.2 and 1.8 L.ton-1. Double application resulted in improved residue loading (0.85 to 2.06 μg.g-1) compared to dip only treatments (≈ 0.49 μg.g-1). Coating only resulted in the highest residue levels (1.82 to 7.09 μg.g-1), often exceeding the maximum residue limit of 5 μg.g-1. In all treatments, poor curative and protective control of the resistant isolate (<46% and <55%, respectively) and generally no sporulation inhibition was observed. For the sensitive isolate, dip only treatments resulted in better curative control (≈ 77%) than protective control (≈ 38%). Double application showed increased protective control with increasing wax load (≈ 69%) as well as good curative control (≈ 83%). Wax coating only treatment resulted in poor curative control (≈ 26%), but good protective control (≈ 80%). Sporulation inhibition of the sensitive isolate was generally improved in treatments that included IMZ application in the wax coating. This study successfully showed the additive benefits of double application of IMZ in the wax coating following an aqueous dip application. However, despite improved control of the sensitive isolate, the resistant isolate could not be controlled. The second objective of the study was to evaluate green mould control and quality preservation following IMZ application using different coating and brush types. The inoculation and treatment procedure was similar to the single application of wax coating described above but only the sensitive isolate of P. digitatum was used. Carnauba- or polyethylene-based wax coatings, including IMZ at 3000 μg.mL-1, was applied at a dosage of 0.6, 1.2 and 1.8 L.ton-1 using commercial horsehair or synthetic brushes. Fruit was either incubated for 4 days prior to wound infection ratings or stored at -0.5oC for 26 days and 7 days shelf life. Imazalil residues on fruit increased with increasing coating loads on navel oranges (1.31 to 3.32 μg.g-1) and Valencia oranges (3.22 to 6.00 μg.g-1). Better protective (≈ 58%) than curative control (≈ 14%) was observed, with horsehair brushes resulting in lower sporulation levels (≈ 59%) than synthetic brushes (≈ 64%). Fruit weight loss and firmness loss ratios relative to uncoated control fruit were significantly higher in fruit treated with polyethylene coating compared with carnauba coating treated fruit. However, polyethylene coating resulted in shinier fruit before and after storage, whereas carnauba coating resulted in lower shine ratios. Gaseous (CO2) exchange ratios remained similar for both coatings, but higher polyethylene coating loads (1.8 L.ton-1) resulted in off-tastes similar to the uncoated control fruit and higher than the ratings for carnauba. Scanning electron micrographs revealed an amorphous crystallised natural wax layer with uncovered stomatal pores on the surface of uncoated fruit. The thickness of the applied coating layer increased with increasing coating load. Coating layers following application with synthetic brushes at 1.2 L.ton-1 appeared to be thicker than when applied using horsehair brushes. This study indicated the effects of brush type on the distribution and polishing of the wax coating on the surface of the fruit and also the importance of cautious application of coating as under or over application may lead to poor results in terms of bio-efficacy, residue loading and fruit quality. / AFRIKAANSE OPSOMMING: Groenskimmel is 'n belangrike sitrus na-oessiekte, veroorsaak deur 'n wondpatogeen, genaamd Penicillium digitatum. Imazalil (IMZ) is die belangrikste na-oesfungisied wat tans teen groenskimmel geregistreer is, gegewe sy goeie beskermende en genesende beheer en sporulasie-inhibisie. Imazalil kan in bad-, doop-, spuit- en wakslaagbehandelings toegedien word. Wakslae behou die kwaliteit van die vrugte gedurende raklewe deur vogverlies te beperk en 'n glansvoorkoms te verskaf. Die primêre doel van hierdie studie was om die toediening van imazalil in wakslaagbehandelings in sitruspakhuise vir groenskimmel en vrugkwaliteit beheer te ondersoek. Die eerste doelwit van hierdie studie was om die beskermende en genesende beheer en sporulasie-inhibisie van IMZ sensitiewe en weerstandbiedende isolate van P. digitatum, gevolg deur enkel IMZ toediening in 'n wakslaagbehandeling, en IMZ toediening in 'n doop-, asook wakslaagbehandeling, te evalueer. Vir enkelltoediening is Valencia lemoenvrugte genesend of beskermend met 'n carnauba-gebaseerde wakslaag behandel, waarin IMZ teen 3000 μg.mL-1 gemeng is. Vir genesende behandelings is vrugte ná 24 uur inkubasie behandel. Wakslaagbehandeling is teen 0.6, 1.2 en 1.8 L.ton-1 vrugte op 'n semi-kommersiële paklyn toegedien. Onbehandelde kontrole en vrugte met waks behandel, het slegs tot 80% infeksie vir beide sensitiewe en weerstandbiedende isolate getoon. Imazalil in waks het beter beskermende as genesende aksie teen die sensitiewe isolaat getoon, terwyl beheer van die weerstandbiedende isolaat swak was. Imazalil residuvlakke het met toename in wakslading toegeneem (0.85 tot 1.75 μg.g-1). Vir dubbeltoediening is clementine, satsuma, navel en Valencia lemoenvrugte gebruik. Genesende en beskermende beheer van IMZ na enkel doopbehandeling (IMZ sulfaat teen 500 μg.mL-1 vir 45 s en 90 s), is met enkel waksbehandeling (IMZ teen 3000 μg.mL-1 teen 1.8 L.ton-1) vergelyk, asook dubbeltoediening bestaande uit doop (45 s in IMZ sulfaat teen 500 μg.mL-1), gevolg deur 2000 μg.mL-1 IMZ in waksbehandeling teen 0.6, 1.2 en 1.8 L.ton-1. Dubbeltoediening het verbeterde residulading (0.85 tot 2.06 μg.g-1) tot gevolg gehad, in vergelyking met enkel doopbehandelings (≈ 0.49 μg.g-1). Enkel waksbehandeling het die hoogste residuvlakke (1.82 tot 7.09 μg.g-1) tot gevolg gehad, wat dikwels die maksimum residu-limiet van 5 μg.g-1 oorskry het. In alle behandelings is swak genesende en beskermende beheer van die weerstandbiedende isolaat (<46% en <55%, onderskeidelik), en oor die algemeen, geen sporulasie-inhibisie, waargeneem. Vir die sensitiewe isolaat, het die enkel doopbehandelings beter genesende beheer (≈ 77%) in vergelyking met die beskermende beheer (≈ 38%) tot gevolg gehad. Dubbeltoediening het verhoogde beskermende beheer met toenemende wakslading (≈ 69%) getoon, asook goeie genesende beheer (≈ 83%). Enkel wakslaagbehandeling het swak genesende beheer (≈ 26%) tot gevolg gehad, maar goeie beskermende beheer (≈ 80%). Sporulasie-inhibisie van die sensitiewe isolaat was oor die algemeen beter in behandelings wat IMZ toediening in die wakslaag ingesluit het. Hierdie studie het suksesvol die toegevoegde voordele van dubbeltoediening van IMZ in doopbehandeling en wakslaag getoon. Ten spyte van die verbeterde beheer van die sensitiewe isolaat, kon die weerstandbiedende isolaat egter nie beheer word nie. Die tweede doelwit was om groenskimmelbeheer en behoud van kwaliteit te evalueer, volgende op IMZ toediening deur gebruik van verskillende waks- en borseltipes. Inokulasie- en behandelingsprosedure was soortgelyk aan die enkeltoediening van wakslaagbehandeling soos bo beskryf, maar slegs die sensitiewe isolaat van P. digitatum is gebruik. Carnauba- of poli-etileen-gebaseerde wakslae, insluitende IMZ teen 3000 μg.mL-1, is teen 'n dosis van 0.6, 1.2 en 1.8 L.ton-1 toegedien, deur die gebruik van kommersiële perdehaar of sintetiese borsels. Vrugte is óf vir 4 dae vóór wond-infeksie evaluering geïnkubeer, óf teen -0.5oC vir 26 dae en 7 dae raklewe gestoor. Imazalil residuvlakke op vrugte het met toenemende waksladings op navellemoene (1.31 tot 3.32 μg.g-1) en Valencia lemoene (3.22 tot 6.00 μg.g-1) toegeneem. Beter beskermende (≈ 58%) as genesende beheer (≈ 14%) is waargeneem, met perdehaar borsels wat laer sporulasievlakke (≈ 59%) tot gevolg gehad het, in vergelyking met sintetiese borsels (≈ 64%). Vruggewig- en fermheidsverlies verhoudings, relatief tot onbedekte kontrole vrugte, was betekenisvol hoër in vrugte wat met 'n poli-etileenwaks behandel is, in vergelyking met carnauba-waks behandelde vrugte. Poli-etileen waksbehandeling het egter blinker vrugte vóór en ná opberging tot gevolg gehad, terwyl canauba waksbehandeling laer blink verhoudings tot gevolg gehad het. Gas (CO2) uitruilverhoudings het dieselfde vir beide waksbehandelings gebly, maar hoër poli-etileen waksladings (1.8 L.ton-1) het tot afsmake soortgelyk aan die onbedekte kontrole vrugte gelei, en hoër as die evaluerings vir carnauba. Skandeer-elektronmikrograwe het 'n amorfe gekristalliseerde natuurlike wakslaag met onbedekte stomata op die oppervlak van onbedekte vrugte getoon. Die dikte van die toegediende waks het met toename in wakslading toegeneem. Wakslae na toediening met sintetiese borsels teen 1.2 L.ton-1 het dikker vertoon in vergelyking met perdehaar borsels. Hierdie studie het die effekte van borseltipe op die verspreiding en polering van die wakslaag op die oppervlak van vrugte getoon, en versigtige toediening van wakslae onderskryf, aangesien ónder- of óórtoediening swak resultate, in terme van bio-effektiwiteit, residu-lading en vrugkwaliteit, tot gevolg kan hê. / National Research Foundation, THRIP, Citrus Academy & Citrus Research International for bursary and research funding.

by Chan Mei-yao Wendy, Yu Yim-sheung Jammy. / Questionnaire in Chinese and English. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 132-133). / abstract --- p.i / table of contents --- p.iii / LIST OF ILLUSTRATIONS --- p.v / LIST OF TABLES --- p.vi / Chapter I. --- INTRODUCTION --- p.1 / Research Objective --- p.1 / Problem Definition --- p.3 / Information Required --- p.4 / Industrial Analysis --- p.8 / Target Customers of Canned Fruits --- p.8 / Role of Hong Kong Fruit Companies in the Canned Fruits Market --- p.10 / Distribution Outlets for Canned Fruits --- p.11 / Advertising and Promotion --- p.11 / Chapter II. --- RESEARCH METHODOLOGY --- p.13 / Data Collection --- p.13 / Sampling Plan --- p.14 / Sample Characteristics --- p.16 / Research Limitations --- p.17 / Questionnaire Settings --- p.17 / Personal Interview --- p.19 / Sampling Method --- p.19 / Chapter III . --- RESEARCH ANALYSIS --- p.21 / Respondents' Attitudes towards Canned Fruits --- p.21 / Taste of the People --- p.21 / Product --- p.22 / Price --- p.25 / Distribution --- p.26 / Consumption Pattern --- p.26 / Ways of Consumption --- p.26 / "Type, Frequency and Brand of Canned Fruits Consumption" --- p.26 / The Favorite Shape of Pineapple and Peach --- p.27 / The Major Reason to Choose Particular Brands --- p.28 / Amount Spent on Canned Fruits per month --- p.29 / Brand Awareness --- p.30 / Brand Loyalty --- p.31 / Purchasing Behaviour --- p.33 / Test for Improvement in Canned Fruits --- p.37 / Chapter IV. --- RECOMMENDATIONS --- p.41 / Recommendations to Del Monte --- p.41 / Price --- p.42 / Variety of Canned Fruits --- p.42 / Recommendations to Other Brands --- p.44 / Distribution Outlets of Canned Fruits --- p.44 / Advertising and Promotion Activities --- p.45 / Recommendations to New Comers --- p.49 / Sourcing of Canned Fruits --- p.49 / Niche Strategy --- p.49 / Direct Competition with Market Leader --- p.50 / Targeting at Other Ways of Consumption of Canned Fruits --- p.52 / Distribution Outlets --- p.54 / Conclusion --- p.54 / Chapter V. --- CONCLUSION --- p.56 / APPENDIX --- p.63 / BIBLIOGRAPHY --- p.132