This thesis has two basic aims. The first aim is to analyze the global value chain of fruits and vegetables and the current international market with apples. The second aim is to analyze the value chain of apples in Czechia and measure its connection to global value chains. The research was carried out by analyzing secondary sources and basing on an own qualitative survey. This thesis is divided into two major parts. The first part deals with the global value chain (GVC) of fruits and vegetables. This chain is examined through five dimensions which are typical for GVC analysis: input-output structure, geographic scope, governance, institutional context and upgrading. The second part focuses only on one specific crop, apples. Firstly, it is studied at the global level, then the thesis concentrates only on the value chain of apples in Czechia.

Made available in DSpace on 2017-07-21T18:53:23Z (GMT). No. of bitstreams: 1 Conclusoes.pdf: 25119 bytes, checksum: cc97815b6091a5ebb507d0a3dc17c116 (MD5) Previous issue date: 2007-09-19 / The apple consumption can contribute in the improvement of the health and well-being by reducing the risk the diseases such as cancer, asthma, diabetes type II and cardiovascular diseases. Scientific evidences indicate that the polyphenols, compounds with high antioxidant activity, are the responsible for this effect. These compounds can vary between varieties, in function of the climate and the cultural treatments. In Brazil little was researched in relation to these constituent in apples, this study presents in one first moment, the analysis of different varieties, considering the whole fruit and their parts, with elaboration of a classification with low and high values. The biggest phenol concentration and antioxidant activity was found in the epicarp. In varieties with different intensities of red pigmentation, the phenolics compounds content was similar, however the antioxidant potential was different. In one second moment the evaluation occurred during the juice and apple wine processing and the responsible factors for the loss of phenols were the enzymatic oxidation and the despectinization. The third moment was reserved for the apple pomace flour that presented high content of polyphenols and antioxidant activity. The results of this study demonstrate that Brazilian apples are fruits with high antioxidant activity. Moreover, apple products can be potent antioxidant sources, since that inhibit the browning enzymatic reaction. / O consumo de maçãs pode contribuir na melhoria da saúde e bem-estar pela prevenção de doenças como câncer, asma, diabetes tipo II e doenças cardiovasculares. Evidências científicas indicam que os polifenóis, compostos com elevada atividade antioxidante, são os responsáveis por este efeito. Estes compostos podem variar entre as cultivares, em função do clima e das condições culturais. Como no Brasil pouco foi pesquisado em relação a esses constituintes nas maçãs, este estudo apresenta em um primeiro momento, a análise de diferentes cultivares, tanto na fruta inteira quanto em suas partes, com obtenção de uma classificação com resultados baixos e elevados. O epicarpo foi a parte da fruta com as maiores concentrações de fenóis e de poder antioxidante. Em cultivares com diferentes intensidades de pigmentação vermelha os teores de compostos fenólicos foram semelhantes, porém a atividade antioxidante foi diferente. No segundo momento a avaliação ocorreu durante o processamento de sucos e fermentados e os fatores responsáveis pela perda de fenóis foram a oxidação enzimática e a despectinização. O terceiro momento foi reservado para as amostras de farinha de bagaço de maçã que apresentaram altos teores de compostos fenólicos e de atividade antioxidante. Os resultados desse estudo demonstram que as maçãs brasileiras são,em grande parte, frutas com elevado potencial antioxidante. Além disso, produtos de maçãs podem ser boas fontes de compostos fenólicos antioxidantes, desde que inibidores do escurecimento enzimático estejam presentes.

Apple scab is the most important disease of apples in most of the world. The disease, caused by Venturia inaequalis, is controlled by numerous fungicide applications, regardless of the presence of inoculum in the orchard. Better timing of fungicide applications could be achieved if the airborne ascospore concentration (AAC) was considered in decision making. AAC can be measured in real time using spore traps. In this project, the relationship between AAC and lesions development was studied under controlled and natural conditions for five cultivars: Empire, McIntosh, Jonagold, Royal Gala, and Spartan. Potted trees were exposed to different airborne ascospore inoculum and the corresponding AAC were measured using spore traps. The spatial distribution of ascospores was studied in a commercial apple orchard plot. The potential ascospore dose (PAD) and the AAC were measured in 40 quadrats in the spring of 1999. (Abstract shortened by UMI.)

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.

Thesis (MscAgric (Horticulture))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: For many apple (Malus domestica Borkh.) and pear (Pyrus communis L.) cultivars, attractive colour is essential to their profitability on export markets. This study focuses on problems related to poor green colour of ‘Granny Smith’ apples and insufficient red colour of bi-coloured pear cultivars. ‘Granny Smith’ apples often suffer from poor green colour. Green colour of fruit from various orchards was already found to differ midway through fruit development, with these differences being carried through to harvest. In a trial where nitrogen (N) fertilisers were applied using different forms at different times, there was no improvement in green colour. In another trial, artificial shading was applied to fruit only during their early development. Fruit that were shaded during this time were less green at harvest than unshaded fruit. Additional N applications may only improve colour where a deficiency exists. However, green colour may be improved by increasing light distribution early during fruit development. Bi-coloured pears attain their maximum red colour midway through their development, and this desired red colour is mostly lost prior to harvest. Red colour can also increase transiently with the passing of cold fronts. Anthocyanins, responsible for this red colour, may have a photoprotective function which would explain this pigmentation pattern, as photosystems are particularly sensitive to light damage at low temperatures. As ‘Rosemarie’ fruit bent over from a vertical to hanging position during development, peel photoinhibition was reduced as anthocyanins were synthesised. ‘Forelle’ peel was found to be very sensitive to high light levels at low temperatures. Substantial anthocyanin development took place in ‘Cripps’ Pink’ apples when weather conditions were cold, but clear following a cold front. A photoprotective role seems to explain daily changes in anthocyanins in response to temperature, but not the seasonal progression of colour development. For many apple (Malus domestica Borkh.) and pear (Pyrus communis L.) cultivars, attractive colour is essential to their profitability on export markets. This study focuses on problems related to poor green colour of ‘Granny Smith’ apples and insufficient red colour of bi-coloured pear cultivars. ‘Granny Smith’ apples often suffer from poor green colour. Green colour of fruit from various orchards was already found to differ midway through fruit development, with these differences being carried through to harvest. In a trial where nitrogen (N) fertilisers were applied using different forms at different times, there was no improvement in green colour. In another trial, artificial shading was applied to fruit only during their early development. Fruit that were shaded during this time were less green at harvest than unshaded fruit. Additional N applications may only improve colour where a deficiency exists. However, green colour may be improved by increasing light distribution early during fruit development. Bi-coloured pears attain their maximum red colour midway through their development, and this desired red colour is mostly lost prior to harvest. Red colour can also increase transiently with the passing of cold fronts. Anthocyanins, responsible for this red colour, may have a photoprotective function which would explain this pigmentation pattern, as photosystems are particularly sensitive to light damage at low temperatures. As ‘Rosemarie’ fruit bent over from a vertical to hanging position during development, peel photoinhibition was reduced as anthocyanins were synthesised. ‘Forelle’ peel was found to be very sensitive to high light levels at low temperatures. Substantial anthocyanin development took place in ‘Cripps’ Pink’ apples when weather conditions were cold, but clear following a cold front. A photoprotective role seems to explain daily changes in anthocyanins in response to temperature, but not the seasonal progression of colour development. Dwarfing rootstocks are known to improve red colour of bi-coloured pears due to improved light distribution. ‘Forelle’ fruit from six rootstocks of varying vigour were harvested from exposed positions only, so as to establish the effect of rootstock on red colour development independent of the effect of rootstock on canopy light distribution. Fruit from trees on quince (Cydonia oblonga Mill.) rootstocks were found to have redder fruit than those from vigorous BP pear rootstocks. This may be due to higher chlorophyll and carotenoid concentrations present in the peel of fruit from BP rootstocks, whose leaf and peel N were also high. The use of quince rootstocks is recommended where red colour development of bi-coloured pears is a problem. An early season bi-coloured cultivar with good red colour is required. Breeding trials to find such a cultivar are resource intensive. To streamline the process, a method to preselect immature seedlings for their future fruit colour is required. Fruit colour from bearing seedlings was compared with colour of their immature leaves. Trees with red leaves were likely to produce fruit that were too red for the breeders’ requirements. Trees with green or blushed leaves were capable of producing blushed fruit. It would be feasible to cull red-leaved seedlings with minimal risk of losing potential bi-coloured cultivars. / AFRIKAANSE OPSOMMING: Verskeie appel (Malus domestica Borkh.) en peer (Pyrus communis L.) kultivars se winsgewendheid word bepaal deur hul aantreklike kleur. In hierdie studie word die swak groen kleur van ‘Granny Smith’ appels asook rooi kleurontwikkeling van blospere ondersoek. Die groen kleur van ‘Granny Smith’ appels is dikwels onvoldoende. Verskille in groen kleur tussen boorde was reeds gedurende vroeë vrugontwikkeling aanwesig, en hierdie verskille het voortgeduur tot met oes. Groen kleur kon nie deur verskillende bronne en tye van stikstofbemesting verbeter word nie. Stikstofbemesting verbeter groen kleur moontlik net in boorde met ‘n stikstoftekort. Vrugte wat gedurende hul vroeë ontwikkeling oorskadu is, se groen kleur was swakker by oes in vergelyking met vrugte wat nie oorskadu is nie. Groen kleur kan moontlik verbeter word deur ligverspreiding tydens vroeë vrugontwikkeling deur middel van snoei aksies te verhoog. Blospeerkultivars bereik hul maksimum rooi kleur halfpad deur hul ontwikkeling, maar is geneig om hul rooi kleur grootliks voor oes te verloor. Rooi kleur mag egter kortstondig toeneem in reaksie op die lae temperature gepaardgaande met koue fronte. Antosianiene, wat verantwoordelik is vir die rooi kleur, het moontlik ‘n beskermende funksie teen hoë ligvlakke, en hierdie funksie mag moontlik die bogenoemde patroon van rooikleurontwikkeling verklaar. Die natuurlike buiging van ‘Rosemarie’ pere van hul aanvanklike regop oriëntasie tot hul karakteristieke hangende posisie, is gekenmerk deur ‘n afname in fotoinhibisie van die skil en ‘n gelyklopende sintese van antosianien. ‘Forelle’ skil was uiters sensitief vir hoë ligvlakke in kombinasie met lae temperature (16 ºC). ‘Cripps’ Pink’ appels het ‘n vinnig toename in rooi kleur getoon met die koue, maar helder, weerstoestande wat gevolg het op ‘n kouefront. Dit is welbekend dat dwergende onderstamme die rooi kleur van blospere verbeter deur ligverspreiding in die boom te verhoog. Ten einde die effek van onderstam op rooi kleurontwikkeling onafhanklik van die effek van onderstam op ligverspreiding te ondersoek, is ‘Forelle’ pere wat blootgestel was aan vol son geoes van bome geënt op ses onderstamme met verskillende groeikrag. Kweperonderstamme (Cydonia oblonga Mill.) het rooi kleur verbeter in vergelyking met die groeikragtige BP peeronderstamme. ‘n Moontlike rede vir die verbetering is die laer chlorofiel- en karotenoïedkonsentrasies in die skil van vrugte op kweperonderstamme. Bome op peeronderstamme het ook hoër blaaren skil stikstofvlakke gehad. Kweperonderstamme word aanbeveel in gevalle waar rooi kleurontwikkeling van blospere ‘n probleem mag wees. Die RSA vrugtebedryf benodig ‘n vroeë blospeerkultivar met goeie rooi kleurontwikkeling. Die teling van so ‘n kultivar is hulpbronintensief en baie duur. Ten einde die teelproses meer effektief te maak, word ‘n metode benodig om saailinge al voor uitplanting in die boord te selekteer na gelang van hul toekomstige vrugkleur. Die vrugkleur van oesryp pere van draende saailinge is vergelyk met die kleur van hul onvolwasse blare. Bome met rooi blare is geneig om vrugte te dra wat té rooi is om te kwalifiseer as blospere. Die meerderheid blospere is afkomstig van bome met blos of groen onvolwasse blare. Dit is prakties haalbaar om rooiblaarsaailinge uit te dun, met net ‘n klein, aanvaarbare risiko om ‘n moontlike blospeerkultivar in die proses te verloor. / medg2010-1 / Imported from http://etd.sun.ac.za April 2010.

Thesis (MSc)--Stellenbosch University, 2004. / Full text to be digitised and attached to bibliographic record. / ENGLISH ABSTRACT: The control of excessive vegetative growth is important in deciduous fruit orchards. Currently the plant growth regulator prohexadione-calcium (p-Ca) is used to control apple shoot growth in the Untited States of America and some European countries. The effect of P-Ca on the shoot and fruit growth of apples (Malus domestica B.), pears (Pyrus cummunis L.), plums (Prunus sa/icina L.) and nectarines (Prunus persica L.) was evaluated. Inhibition of shoot growth can effect fruit growth. Therefore I did a literature review on the fruit growth of pome- and stone fruit. Split pit, a physiological disorder associated with an increased fruit growth rate in stone fruit, was also investigated. During the course of the 2001 / 2002 season two trials were conducted in the Villiersdorp area of the Western Cape on 'Golden Delicious' and 'Granny Smith' apple trees. Single and multiple applications of P-Ca at different rates, with and without the surfactant Dash®, were applied. One of these trials was continued during the 2002 / 2003 season. In the 2001 / 2002 season, P-Ca reduced shoot growth in both trials on 'Golden Delicious'. The shoot growth of 'Granny Smith' was reduced in both trials where PCa was applied three or four times. There was an improvement in the fruit size of 'Golden Delicious' in both trials, but there was no improvement in the fruit size of 'Granny Smith'. In the 2002 / 2003 season, the single P-Ca application did not reduce shoot growth. Unfortunately 'Golden Delicious' was harvested before any data were obtained. Once again P-Ca had no effect on the fruit size of 'Granny Smith'. Dash® did not improve the effect ofP-Ca. In the 2002 / 2003 season we replicated one trial on five different pear cultivars in the Wolsely area of the Western Cape. Single and multiple applications of P-Ca at different rates were compared to a girdling treatment (2 weeks after full bloom). 'Early Bon Chretien', 'Rosemarie', 'Flamingo', 'Forelle' and 'Packham's Triumph' pear trees were used and Dash®was added to all 0f the treatments. P-Ca reduced shoot growth in all of the pear cultivars. Girdling reduced shoot growth only in 'Forelle'. P-Ca increased fruit set of 'Early Bon Chretien', 'Rosemarie' and 'Forelle', however, this was associated with a reduced fruit size of 'Early Bon Chretien' and 'Rosemarie'. Girdling did not increase fruit set, but increased fruit size of 'Flamingo' and 'Early Bon Chretien'. P-Ca reduced return bloom of 'Packham's Triumph' and 'Forelle', whereas girdling increased return bloom in all the cultivars except 'Packham's Triumph'. In the 2002 / 2003 season, trials were also conducted on 'Pioneer' and 'Songold' plums and 'May Glo' nectarine in the Wemmershoek and Stellenbosch area of the Western Cape. Single applications at different rates of P-Ca were applied. Dash® was added to all of the treatments. The higher rates of P-Ca reduced the shoot growth of 'Pioneer'. P-Ca only reduced shoot growth of 'Songold' initially and but did not reduce shoot growth of 'May Glo'. P-Ca had no influence on fruit size of 'Pioneer', 'Songold' or 'May Glo'. P-Ca did not aggravate the occurrence of split pit. In conclusion, P-Ca reduced shoot growth in apples and pears when applied at the appropriate rates. Although P-Ca reduced shoot growth of 'Pioneer' plum, more research needs to be done on stone fruit to optimise timing and rate of P-Ca applications. / AFRIKAANSE OPSOMMING: Die beheer van oormatige lootgroei is van kardinale belang in vrugtebome. Tans word die plantgroeireguleerder proheksadioon-kalsium (P-Ca) gebruik om die lootgroei van appels te beheer in die Verenigde State van Amerika en sekere lande in Europa. Die effek van P-Ca op lootgroei en vruggrootte is in proewe op appels (Malus domestica B.), pere (Pyrus cummunis L.), pruime (Prunus salicina L.) en nekatriens (Prunus persica L.) geëvalueer. Aangesien lootgroei inhibisie moontlik vruggroei kan vesnel, is 'n literatuurstudie oor die vruggroei van kern-en steenvrugte gedoen. Die ontwikkelling van gesplete pit by steenvrugte ('n fisiologiese defek geassosieer met versnelde vruggroei) is ook ondersoek. Gedurende die 2001 / 2002 seisoen is P-Ca in twee afsonderlike proewe in die Villiersdorp area van die Wes Kaap geëvalueer. Enkel en veelvuldige toedienings van verskeie konsentrasies P-Ca, met en sonder die benatter Dash", is op 'Golden Delicious' en 'Granny Smith' bome toegedien. Een proef is herhaal gedurende die 2002 / 2003 seisoen. In die 2001 /2002 seisoen het die P-Ca behandelings in beide proewe die lootgroei van 'Golden Delicious' verminder. Die lootgroei van 'Granny Smith' is in beide proewe verminder waar P-Ca 3 of 4 keer toegedien is. Die vruggrootte van 'Golden Delicious', maar nie 'Granny Smith' nie, is in beide proewe deur die P-Ca verbeter. In die 2002 / 2003 seisoen kon die enkeltoedienings van P-Ca nie die lootgroei verminder van 'Golden Delicious' of 'Granny Smith' nie. 'Golden Delicious' is geoes voor enige inligting oor die vruggrootte ingesamel kon word. Weereens het PCa geen invloed op die vruggrootte van 'Granny Smith' gehad nie. Dash® het nie die effek van P-Ca verbeter nie.In die 2002 / 2003 seisoen is proewe met P-Ca gedoen op 5 verskillende peer kultivars in die Wolsely area van die Wes Kaap. P-Ca is teen verskillende konsentrasies, met enkel en veelvuldige bespuitings toegedien en vergelyk met 'n ringelerings behandeling (2 weke na volblom). 'Early Bon Chretien', 'Rosemarie', 'Flamingo', 'Forelle' en 'Packham's Triumph' bome is gebruik en die benatter Dash® is by al die behandelings gevoeg P-Ca toedienings het lootgroei verminder in 'Early Bon Chretien', 'Rosemarie', 'Flamingo', 'Forelle' en 'Packham's Triumph'. Ringelering kon slegs die lootgroei van 'Forelle' verminder. P-Ca het die vrugset van 'Early Bon Chretien', 'Rosemarie'en 'Forelle' verhoog. Die toename in vrugset het gelei tot 'n afname in die vruggrootte van 'Early Bon Chretien' en 'Rosemarie'. Ringelering het die vruggrootte van 'Flamingo' en 'Early Bon Chretien' verbeter. P-Ca het 'n afname in die hoeveelheid reproduktiewe knoppe in die volgende seisoen, van 'Packham's Triumph' en 'Forelle' veroorsaak. Ringelering het 'n toename in die hoeveelheid vegetatiewe knoppe in die volgende seisoen gehad vir al die kultivars, behalwe 'Packham's Triumph'. Geduerende dieselfde seisoen is daar ook proewe gedoen op 'Pioneer' en 'Songold' pruime en 'May Glo' nektarienbome in onderskeidelik die Wemmershoek en Stellenbosch areas van die Wes Kaap. Bome is met enkel toedienings van verskillende konsentrasies P-Ca behandel en die benatter Dash® is by al die behandelings bygevoeg. Die hoër dosisse P-Ca het die lootgroei van 'Pioneer' verminder. P-Ca kon slegs die aanvanklike lootgroei op 'Songold' verminder en kon nie lootgroei van 'May Glo' beperk nie. P-Ca het geen invloed op die vruggrootte van 'Pioneer', 'Songold' of 'May Glo' gehad nie. P-Ca het nie die voorkoms van gesplete-pit vererger nie. Om saam te vat kan gesê word dat P-Ca lootgroei op appels en pere goed beperk teen die regte konsentrasies. Alhoewel P-Ca lootgroei suksesvol beheer het op 'Pioneer', moet daar meer werk gedoen word op steenvrugte.

Thesis (MScAgric)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Excessive shoot growth of fruit trees may have various negative effects. These include a decrease in fruit set, fruit size, red colour and in return bloom. Cultural practices that are currently in use, such as the use of dwarfing rootstocks, girdling and pruning do not always give sufficient shoot growth control. The use of plant growth retardants, in combination with these cultural practices, offer additional possibilities. Trials were conducted to evaluate the effect of the new plant growth retardant prohexadione-calcium (P-Ca) on apple, pear and plum shoot growth. In addition, the effect of P-Ca on fruit set, fruit size, yield, fruit quality and return bloom were also evaluated. During the 1999/2000 season P-Ca was applied to full bearing twelfth leaf 'Golden Delicious' trees on M793 rootstock, twenty-sixth leaf 'Granny Smith' trees on seedling rootstock, ninth leaf 'Royal Gala' trees on M793 rootstock, seventh leaf 'Rosemarie' trees on seedling rootstock and eighth leaf 'Songold' trees on 'Marianna' rootstock in the Villiersdorp area in the Western Cape (33°59' S, 19°17' E; ca. 365 m a.s.l.; Mediterranean climate). P-Ca was applied at concentrations of 3 x 50, 4 x 50 and 3 x 67 mg.l' to the apple trees. The first application was at petal drop with no surfactant added with any of the treatments. P-Ca was applied at concentrations of2 x 62.5,125,250 and 2 x 125 mg.l" to the pear and plum trees. The first application was at petal drop and pit-hardening for the pear and plum trees respectively. Agral-90 was used as surfactant only with the first spray applied to the pear trees. During the 2000/2001 season the same 'Golden Delicious' and 'Royal Gala' trees were used as in the 1999/2000 season. Thirteenth leaf 'Granny Smith' trees on M793 rootstock in the Villiersdorp area were used. Sixth leaf 'Rosemarie' trees on BP3 rootstock, fifth leaf 'Golden Russet Bose' trees on BP3 rootstock, seventh leaf 'Forelle' trees on BP3 rootstock and 16th leaf 'Packham's Triumph' trees on seedling rootstock in the Wolseley area in the Western Cape were used. P-Ca was again applied at concentrations of 3 x 50,4 x 50 and 3 x 67 mg.l' to the apple trees. The first application in the 'Golden Delicious' and 'Granny Smith' trees was at full bloom and at petal drop in the 'Royal Gala' trees. The last application was at 45 days before harvest. No surfactant was added with any of the sprays. P-Ca was applied at concentrations of 50, 75, 150, 2 x 50,2 x 75 and 3 x 50 mg.l" to the pear trees with the first spray when 4 to 5 leaves were unfolded and the last one 45 days before harvest. Agral-90 was added as surfactant with all the pear sprays. The pear trial also included a girdling treatment. P-Ca effectively inhibited shoot growth of all three apple cultivars in both seasons. Regrowth occurred in both seasons in all the cultivars, therefore it is not clear which treatment(s) is optimal for reducing shoot growth. P-Ca increased fruit size in 'Royal Gala' in the 1999/2000 season and decreased yield expressed as kg fruit harvested 1 em trunk circumference in 'Golden Delicious' in the 2000/2001 season. This reduction in yield can be attributed to the low number of flower clusters in the spring of 2000 following P-Ca treatment in 1999. P-Ca decreased the number of developed seeds in 'Royal Gala' in both seasons and increased the number of seeds with aborted embrios in the 200012001 season. After four weeks of cold storage (± 5°C) and one week at room temperature (± 20°C), P-Ca had no effect on the occurrence of bitter pit in 'Golden Delicious'. The 'Granny Smith' trees were harvested before fruit analysis could be done in the 2000/2001 season. In pear, girdling was not effective in inhibiting shoot growth in any of the cultivars, but P-Ca proved to be an effective inhibitor of shoot growth of 'Rosemarie' and 'Golden Russet Bose', and to a lesser degree 'Packham's Triumph', but not 'Forelle'. Despite the re-growth that occurred ca. four weeks after harvest in 'Rosemarie' in the 2000/20001 season, it appears that a single high rate (250 and 150 mg.l' for the 1999/2000 and 2000/2001 seasons respectively) P-Ca application is more effective than a single low rate or multiple low rates in inhibiting shoot growth. In the 200012001 season P-Ca increased fruit set in 'Rosemarie' and 'Forelle'. In both seasons P-Ca reduced 'Rosemarie' fruit size while girdling increased 'Forelle' and 'Packham's Triumph' fruit size in 2000/2001. P-Ca increased 'Rosemarie' fruit firmness and 'Forelle' fruit colour in the 2000/2001 season and decreased the percentage of 'Packham's Triumph' fruit with cork spot. Girdling increased 'Packham's Triumph' fruit colour and TSS concentration while decreasing fruit firmness in 2000/2001. P-Ca reduced return bloom in 'Forelle' and 'Packham's Triumph' in 2001, while girdling increased 'Golden Russet Bose' and 'Forelle' return bloom. Due to poor flowering and thus low fruit number in 'Golden Russet Bose', fruit set in 2000 could not be determined and no fruit analysis could be done. In 'Songold' all four P-Ca treatments inhibited shoot growth, but the 2 x 125 mg.l' treatment were the most effective, both in terms of total shoot growth and in reduction of the re-growth that occurred ca. two weeks before the first commercial harvest date. P-Ca increased fruit firmness and decreased TSS concentration both at harvest and after four weeks of cold storage at dual temperature (10 days at -O.soC + 18 days at 7.S°C). In conclusion P-Ca is an effective inhibitor of shoot growth of the apples 'Golden Delicious', 'Granny Smith' and 'Royal Gala', the pears 'Rosemarie', 'Golden Russet Bose' and 'Packham's Triumph' and the plum 'Songold', but more work is needed to control re-growth. / AFRIKAANSE OPSOMMING: Oormatige lootgroei van vrugtebome kan verskeie negatiewe effekte tot gevolg he, insluitende 'n afname in vrugset, vruggrootte, rooi kleur en 'n verlaging in die daaropvolgende jaar se blom. Boordpraktyke soos die gebruik van dwergende onderstamme, ringelering en snoei, beheer nie altyd lootgroei doeltreffend nie. Die gebruik van groeireguleerders, in kombinasie met hierdie boordpraktyke, bied bykomende geleenthede. Proewe is uitgevoer om die effek van die nuwe groeireguleerder proheksadioon-kalsium (PCa) op appel, peer en pruim lootgroei te evalueer. Die effek van P-Ca op vrugset, vruggrootte, opbrengs, vrugkwalitiet en die daaropvolgende jaar se blom is ook geevalueer. Gedurende die 1999/2000 seisoen is P-Ca toegedien aan voldraende twaalfde blad 'Golden Delicious' bome op M793 onderstamme, ses-en-twintigste blad 'Granny Smith' bome op saailing onderstamme, negende blad 'Royal Gala' bome op M793 onderstamme, sewende blad 'Rosemarie' bome op saailing onderstamme en agste blad 'Songold' bome op 'Marianna' onderstamme in die Villiersdorp area in die Wes Kaap (33°25' S, 19°12' 0; ligging ong. 270 m.; Meditereense klimaat). P-Ca is aan die appelbome toegedien teen konsentrasies van 3 x 50, 4 x 50 en 3 x 67 mg.l' met die eerste toediening by blomblaarval. Geen benatter is by enige van die toedienings gevoeg nie. P-Ca is aan die peer- en pruimbome toegedien teen konsentrasies van 2 x 62.5, 125, 250 en 2 x 125 mg.l' met die eerste toediening by blomblaarval en pitverharding vir onderskeidelik die peer- en pruimbome. Agral-90 is as benatter gebruik slegs saam met die eerste toediening op die peerbome. Tydens die 2000/2001 seisoen is dieselfde 'Golden Delicious' en 'Royal Gala' bome gebruik as in die 1999/2000 seisoen. Derde blad 'Granny Smith' bome op M793 onderstamme in die Villiersdorp area is gebruik. Sesde blad 'Rosemarie' bome op BP3 onderstamme, vyfde blad 'Golden Russet Bose' bome op BPI onderstamme, sewende blad 'Forelle' bome op BP3 onderstamme en sestiende blad 'Packham's Triumph' bome op saailing onderstamme in die Wolseley area in die Wes Kaap is gebruik. P-Ca is weereens aan die appelbome toegedien teen konsentrasies van 3 x 50, 4 x 50 en 3 x 67 mg.l". Die eerste toediening aan die 'Golden Delicious' en 'Granny Smith' bome was by volblom en die eerste toediening aan die 'Royal Gala' bome by blomblaarval. Die laaste toediening is 45 dae voor oes gedoen. Geen benatter is met enige van die toedienings bygevoeg nie. P-Ca is aan die peerbome toegedien teen konsentrasies van 50, 75, 150,2 x 50, 2 x 75 en 3 x 50 mg.l' met die eerste toediening toe vier tot vyf blare ontvou was en die laaste een 45 dae voor oes. Agral-90 is as benatter gebruik met al die peer bespuitings. By die peer proef is ook 'n ringeleer behandeling ingesluit. In beide seisoene het P-Ca die lootgroei van al drie appel kultivars verminder. Hergroei het in beide seisoene in al drie kultivars plaasgevind. Dit is dus onduidelik watter behandeling(s) optimaal is vir lootgroei beheer. In die 1999/2000 seisoen het P-Ca 'Royal Gala' vruggrootte verbeter. In die 2000/2001 seisoen is 'Golden Delicious' opbrengs, uitgedruk as kg vrugte geoes / cm stamomtrek, verlaag. Hierdie verlaging in opbrengs kan toegeskryf word aan die lae blom aantal in die lente van 2000 wat gevolg het op die P-Ca behandeling in 1999. In beide seisoene het P-Ca die aantal ontwikkelde sade in 'Royal Gala' verminder terwyl die aantal sade met geaborteerde embrios verhoog is in die 2000/2001 seisoen. Na vier weke koelopberging (± 5°C) en een week by kamertemperatuur (± 20°C) het P-Ca geen effek op die voorkoms van bitterpit in 'Golden Delicious' gehad nie. Die 'Granny Smith' bome is in die 2000/2001 seisoen geoes voordat enige data ingesamel kon word. Ringelering het geen effek op lootgroei gehad in enige van die peer kultivars nie, maar P-Ca het lootgroei effektief beheer in 'Rosemarie' en 'Golden Russet Bose' en tot 'n mindere mate 'Packham's Triumph', maar het geen effek op 'Forelle' lootgroei gehad nie. Ten spyte van die hergroei wat voorgekom het in die 'Rosemarie' bome ongeveer vier weke na oes in die 2000/2001 seisoen, wil dit voorkom asof P-Ca toegedien teen 'n enkele hoe konsentrasie (250 en 150 mg.l' vir die 1999/2000 en 2000/2001 seisoene onderskeidelik) meer effektief was om lootgroei te beheer as 'n enkele lae konsentrasie of veelvuldige lae konsentrasies. P-Ca het vrugset in 'Rosemarie' en 'Forelle' verhoog in die 2000/2001 seisoen. In beide seisoene het P-Ca 'Rosemarie' vruggrootte verlaag terwyl ringelering 'Forelle' en 'Packham's Triumph' vruggrootte verbeter het in die 2000/2001 seisoen. P-Ca het 'Rosemarie' vrugfermheid en 'Forelle' vrugkleur verhoog in die 2000/2001 seisoen en die aantal 'Packham's Triumph' vrugte met kurkvlek verlaag. Ringelering het 'Packham's Triumph' vrugkleur en TSSkonsentrasie verhoog, maar vrugfermheid verlaag in die 2000/2001 seisoen. P-Ca het die aantal blomme in 'Forelle' en 'Packham's Triumph' verlaag in 2001, terwyl ringelering blom in 'Golden Russet Bosc' en 'Forelle' verhoog het. As gevolg van 'n lae blom- en dus vruggetal in 'Golden Russet Bosc' kon vrugset In 2000 nie bepaal word nie en geen vrugontledings kon gedoen word nie. Al vier P-Ca behandelings het lootgroei in 'Songold' beheer, maar die 2 x 12S mg.l' toediening was die effektiefste, beide in terme van totale lootgroei en in beheer van die hergroei wat ongeveer twee weke voor die eerste kommersieele oesdatum plaasgevind het. PCa het vrugfermheid verhoog en die TSS-konsentrasie verlaag, beide tydens oes en na vier weke koelopberging by dubbel temperatuur (10 dae by -O.soC + 18 dae by 7.S0C). Om saam te vat kan gese word dat P-Ca 'n effektiewe inhibeerder van lootgroei van die appels 'Golden Delicious', 'Granny Smith' en 'Royal Gala', die pere 'Rosemarie', 'Golden Russet Bosc' en 'Packham's Triumph' en die pruim 'Songold' is. Meer werk is egter nodig om die hergroei te beheer.

Thesis is focused on thy drying of apples and their changes during long-term storage. The theoretical part was written using the research, which brings findings about the drying of apples, their requirements during sale, selection of right raw material, interventions against enzymes and sensory analysis. The sensory analysis was a significant part of the practical part, because the practical part was based on it. Objective of the thesis was to compare three varieties of dried apples. By the scaling-point test there were not discovered by differences between varieties, but during each assessed descriptor there was discovered, that the quality is decreasing. The serial test was used as a second test of the sensory analysis, which determined the development of sensory quality and ordering of samples from the best to the worst. It was discovered, that all there varieties kept their specific characteristics for five months, i.e. eight months from the commencement of production. Longer storage was assessed as inconvenient.