Bibliography: last 24 unnumbered leaves / 161, [32] leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1985

xvii, 215 leaves : ill. ; 30 cm.0 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, 1974

xvii, 255 leaves : photos, tables, graphs ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Physiology, 1979

xvii, 215 leaves : ill. ; 30 cm.0 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, 1974

Thesis (Ph.D.)--Materials Science and Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Speyer, Robert; Committee Member: Gerhardt, Rosario; Committee Member: Liu, Meilin; Committee Member: Lynch, Christopher; Committee Member: Wilkinson, Angus

No description available.

Thesis (MScAgric)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Lemons with an elongated fruit shape achieve premium prices in certain discerning markets. Factors influencing the fruit shape of lemons were investigated to fmd means to produce a crop with a higher percentage of elongated lemons. Intra-plant factors were investigated to understand the variation in fruit shape within a single tree and even within the same fruit cluster. Bearing position (leafy vs. leafless inflorescences) and position in the canopy (inside vs. outside) were taken into consideration, along with the number of seeds, number of segments and rind thickness in the center of the fruit as well as stem- and stylar-ends. Bearing position and position in the canopy had no effect on fruit shape, while the number of seeds was positively correlated with elongated lemons. Rootstocks were evaluated to determine the influence of rootstock type on fruit shape. Twelve rootstocks were evaluated in total, at Addo, Citrusdal and Nelspruit. At all three locations rootstock type had no or little influence on fruit shape. Different scions were also evaluated at both Addo and Citrusdal to determine whether a certain scion characteristically produces elongated fruit. A total of 20 different scions were evaluated, and as opposed to rootstocks, there were larger variations between scions. Of the commercially-produced scions, 'Fino' lemon had the least variation, producing elongated lemons more consistently than 'Lisbon' and 'Eureka' lemons. Of the other scions, 'Cicily' lemon produced fruit with the smallest L:D ratio, while 'Vema' lemon was the scion producing fruit with the largest L:D ratio. 'Vema' lemon is, however, not an attractive fruit, having a thick rough rind. In the case of grapefruit, unwanted "sheepnosed" fruit with thick rinds are common in areas with a low winter temperature at night. 'Eureka' lemon fruit from six different climatic areas were compared to evaluate the difference in fruit shape. Cooler areas, such as Vaalharts, had more elongated fruit than areas with a higher winter temperature, such as Nelspruit. Altering lemon fruit shape was also attempted by chemical manipulation, usmg gibberellin, cytokinin or auxin containing products. Promalin® (GA4+7, BA), Accet" (GA4+7, BA), Corasil E® (2,4-D), Provide® (GA4+7) and ProGibb® (GA)) were sprayed at different times and different concentrations. Promalin'" was partly successful in altering fruit shape, but these changes were not large enough from a commercial point of view. Promalin'" also resulted in a lower percentage fruit set. Accel'", Corasil E®, Provide® and ProGibb® were not successful in altering fruit shape favorably, with Corasil E® having a strong thinning effect. / AFRIKAANSE OPSOMMING: Fakore wat die verlenging van suurlemoene beïnvloed Suurlemoene met 'n verlengde vrugvorm behaal hoë pryse in sekere markete. Faktore wat die vrugvorm van suurlemoene beïnvloed is bestudeer om praktyke te vind wat die produksie van verlengde suurlemoene kan verhoog. Intra-plant faktore is bestudeer om die variasie in vrugvorm binne 'n enkele boom en ook in dieselfde vrugtros te verstaan. Dra-posisie ("wit" en "groen" blomme) asook posisie in die boom (binnevrugte vs. buitevrugte ) is in aanmerking geneem. Die invloed van die hoeveelheid sade en segmente per vrug, asook skil dikte in die middle van die vrug en aan stingel- en kelkkant is ook bestudeer. Dra-posisie en posisie van vrug in die boom, het geen invloed op vrugvorm gehad nie, terwyl die hoeveelheid sade per vrug die beste met vrugvorm gekorreleer was. Die invloed van onderstam tipe op vrugvorm is ook geëvalueer. Vrugvorm van twaalf onderdstamme in totaal is te Addo, Citrusdal en Nelspruit ondersoek. By al drie areas is klein verskille in vrugvorm van verskillende onderstamme opgemerk. Saam met die onderstamme is 20 seleksies te Addo en Citrusdalondersoek, om te bepaal of 'n sekere seleksie 'n karakteristieke verlengde vrugvorm openbaar. In teenstelling met onderstamme, is groter variasie tussen seleksies gevind. Vandie kommersiële kultivars, het 'Fino' suurlemoen die minste variasie openbaar en deurgans verlende vrugte gelewer, terwyl 'Lisbon' en 'Eureka' suurlemoene groter variasie gehad het. Vandie ander seleksies, het 'Cicily' suurlemoen geneig om vrugte met die kleinsteL:D verhouding te lewer, terwyl'Vema' suurlemoen deurgans vrugte met 'n groter L:D verhouding gelewer het. 'Vema' suurlemoen is egter nie 'n aantreklike vrug nie, aangesien dit 'n dik skil het. In die geval van pommelos word ongewenste vrugte met 'n "skaapneus" vorm algemeen aangetref in areas met 'n lae mininmum winter temperatuur. Vrugvorm van 'Eureka' suurlemoene van ses verskillende klimaats areas is vergelyk. Koeler areas, soos Vaalharts, het meer verlengde vrugte gehad, terwyl Nelspruit met 'n hoër winter temperatuur, ronder vrugte produseer het. Daar is ook gepoog om suurlemoen vrugvorm te manipuleer d.m.v. chemiese bespuitings. Ouksiene, gibbereliene en sitokiniene asook kombinasies daarvan, is gebruik. Promalin® (GA4+7, BA), Accel® (GA4+7,BA), Corasil E® (2,4-D), Provide® (GA4+7) en ProGibb® (GA3) is by verskillende tye en verskillende konsentrasies gespuit. Promalin® was gedeeltelik suksesvol in verlenging van vrugte, maar die veranderinge was te klein uit 'n kommersiële oogpunt. Promalin® het ook tot uitdunning van vrugte gelei. Accel", Corasil E®, Provide® en ProGibb® was nie suksesvol in verandering van suurlemoen vrugvorm nie. Corasil E®het tot strawwe vruguitdunning gelei.

Thesis (MScAgric)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: In order to study the dormancy of apple buds in conditions of inadequate chilling a number of trails were done during 2000 and 2001. Year-old, unbranched shoots of 'Royal Gala', 'Braeburn', 'Cripps' Pink' and 'Granny Smith' apple were harvested randomly from bearing commercial orchards in the Koue Bokkeveld [33°S, 945m, ca.1300 Utah model chili units (CU)) and Elgin (34 "S, 305m, ca.750CU) regions of the Western Cape, South Africa, respectively. Shoots were chilled at 5-rC. Two replicate bundles were removed from the cold room, prepared and forced at 25°C with continuous illumination until budburst had occurred on at least 25% of the shoots per bundle. The change in the rate of budburst over time was calculated for each orchard and to this response; either a linear or a quadratic function was fitted. Poorly correlated variables were selected that best describe these functions. Using these variables, the orchards were separated into cluster groupings that represented a dormancy pattern. The first split separated the lower chilling requirement cultivars from the higher cultivars. The second and third split separated the orchards according to area differences. The clusters representing the warmer area orchards initially entered deeper into dormancy before exiting. The clusters for the colder area immediately had an increased budburst rate. This data confirm that the chilling requirement includes a period of dormancy induction. An important genotype and environment interaction, other than cold unit accumulation, was observed that could be responsible for terminating bud dormancy. Terminal apple buds from 'Royal Gala' Braeburn', 'Cripps' Pink' and 'Granny Smith' apples were cut from orchards in the Koue Bokkeveld and Elgin regions of the Western Cape, South Africa. Buds were harvested every two weeks during the dormant period. The buds were cut in half and leaf scales removed before the water potential were measured. Fresh and dry weights of the buds were also determined. The data presented confirms the changes in availability of free water in dormant buds and that it could be measured in this way. A definite influence of temperature was illustrated. The water potential from buds in a cold production area (Koue Bokkeveld) behaved more "normally" - water is in a bound form during most of the winter and change to an available form later in winter - whereas buds from a warmer production area did not change much in water potential or content. In the trial, two-year-old proleptic-branched shoots, ca. 500mm long, were selected from a 'Royal Gala' orchard in the Koue Bokkeveld region in the Western Cape, South Africa. During the dormancy period of 2000, shoots received two cold treatments; chilling in a cold room at 5-7°C and the natural chilling received in the field. In 2001, the trail was repeated, but only with the field chilling. The shoots received five dormant pruning treatments: control (not pruned), pruning back to the fourth lateral (heading) before or after chilling; and removal of the 2nd and 3rd laterals (thinning) before or after chilling. After pruning and chilling treatments, the shoots were removed from the orchard or cold room every two weeks and forced in a growth chamber. The rate of bud burst (1/days to 50% bud burst) was calculated for the terminal buds of the lateral shoots. Laterals were categorisation according to position: the terminal extension shoot, the 4th lateral, and all other laterals were pooled. Removing distal tissue by pruning (heading more than thinning) promoted bud burst on laterals. Pruning before chilling was more effective than after chilling. The correlative phenomena that inhibit bud burst on proximal shoots within two-yearold branches were manipulated by pruning. The branching response of one-year-old unbranched shoots, 0.5m long, from 'Royal Gala' and 'Cripps' Pink' apple and 'Rosemary' pear were studied after physical manipulation treatments. Shoots for treatment a to d were re-orientated from either a horizontal or vertical position or left in the original position as control, treatment e to h involved the same re-orientation of shoots and were headed. The amount of growth (in mm) from each node was recorded as well as the position from the terminal bud. The 'Cripps' Pink' had a definite shift in the acrotonic branching pattern (for headed and unheaded), towards a more basitonic response. The reduced effect on 'Royal Gala' and 'Rosemary' suggest a difference in genotype response to the treatments as well as time of treatment. / AFRIKAANSE OPSOMMING: Ter wille van die navorsing oor die invloed van gebrekige koue op dormansie van apple knoppe en die gepaardgaande probleme is 'n reeks proewe gedoen gedurende 2000 en 2001. Jaar oue onvertakte lote van 'Royal Gala', 'Braeburn' , 'Cripps' Pink' en 'Granny Smith' appels is ewekansig geoes vanaf komersieële boorde in die Koue Bokkeveld [33°S, 945m, ca.1300 Utah koue eenhede (CU)] en Elgin (34°S, 305m, ca.750CU) omgewings van die Wes Kaap , Suid Afrika. Die lote is daarna verkoel gehou by 5- 7°C. Lote is elke twee weke vanuit die koue kamer geneem en geforseer met 25°C en deurlopend belig. Die aantal knoppe wat groenpunt bereik het is genoteer totdat 25% van die lote begin bot. Die verandering oor tyd vir elke boord is bereken en 'n liniëre of kwadratiese funksie is daarop gepas. Swak gekorreleerde waardes is gekies wat die funksies die beste beskryf. D.m.v hierdie die waardes is die boorde in groepe ingedeel wat 'n dormansie patroon verteenwoordig. Na die eerste vedeeling is die hoë en lae koue behoefte kultivars geskei. In opvolgende verdelings is die boorde verder in die twee areas geskei met elk 'n spesifieke dormansie patroon. Die groepe wat die warmer area se boorde bevat het aanvanklik dieper in dormansie in beweeg voor dit 'n styging in groei potensiaal getoon het. Die groepe vanaf die kouer produksie area het onmiddelik 'n verhooging in bot tempo getoon. Die data bevestig dat 'n koue behoefte 'n periode van dormansie induksie insluit. 'n Belangrike kultivaromgewing- interaksie, ten spyte van koue eenhede akkumulasie, is waargeneem wat verantwoordlik kan wees vir beëindiging van dormansie. Om die verandering van water status in dormante appel knoppe te bestudeer, was die volgende proef uitgevoer. Terminale apple knoppe van dieselfde vier kultivars en vanaf die selfde twee areas in die Wes Kaap as bogenoemde, is elke tweede week gedurende die winter 2001 gesny vanaf komersieële boorde. Daarna is die knoppe middel deur gesny en die skudblare verwyder voor die vars massa gemeet en daarna die waterpotensiaal bepaal is. Die data het bevestig dat daar veranderings in beskikbaarheid van vry water in dormante knoppe gedurende dormansie plaasvind. 'n Definitiewe invloed van temperatuur op waterpotensiaal is geïllustreer. Die waterpotensiaal van knoppe in die kouer produksie area toon 'n meer normale respons (gedurende die winter is die water in 'n gebonde vorm, wat later in die winter na vry water verander). Daar teenoor is daar in die knoppe van die warm produksie area nie veel verandering in waterpotensiaal of water massa getoon nie. Gedurende die winter van 2000 is twee jaar oue proleptiese vertakte 'Royal Gala' lote, ongeveer 500mm lank, gekies vanaf 'n boord in die Koue Bokkeveld. Die lote is verdeel en het twee koue behandelings ontvang. Koue kamer by 5-T'C en natuurlike koue in die boord. In 2001 is net die natuurlike koue behandeling herhaal. Daar is vyf dormante snoei behandeling op die lote gedoen; kontrole (geen), snoei terug tot die vierde lateraal voor en na die koue; verwydering van die 2de en 3de laterale voor en na koue. Na koue en snoei is die lote verwyder en in die groeikamer geforseer by 25°C en met konstante illuminasie. Die tempo waarteen die laterale gebot het is bereken (1\dae to 50% groen punt) waarna die laterale in klasse gedeel is; terminale knop, die vierde lateraal en die res van die laterale saam. Verwydering van distale weefsel d.m.V. snoei verhoog die tempo waarteen laterale knoppe groenpunt bereik. Snoei voor die koue behandeling was meer effektief as daarna. Die korrelatiewe fenomeen wat bot inhibeer van proksimale lote kan gemanipuleer word in die twee jaar apple loot. Die vertakkings gedrag van een jaar oue onvertakte 'Royal Gala', 'Cripps' Pink' apple en 'Rosemary' peer lote, 0.5m lank, is ondersoek na fisiese manipulasies gedoen is gedurende mid winter 2000. Vir die eerste vier behandelings (a,b,c,d) is die lote in 'n horisontale of vertikale possisie gelos as kontrole, of horisontale of vertikale gebuig en daar gehou d.m.v. binddraad. Behandelings e tot h het dieselfde behels maar die lote is ook nog in die helfte deur gesny (getop). Die hoeveelheid groei in mm vir elke node is aangeteken asook die posisie vanaf die terminale knop. Die 'Cripps' Pink' het 'n definitiewe veskuiwing vanaf 'n akrotoniese na 'n basitoniese vertakkingspatroon getoon. Die reaksies op die manipulasies of die gebrek daaraan ('Royal Gala' en 'Rosemary' ) kan 'n aanduiding wees dat genotipes verskillend reageer op die behandelings asook op die tyd wat dit gedoen was.

M.Sc. / Please refer to full text to view abstract

Experiments were conducted in controlled-environment cabinets to show the effect of temperature and light intensity on the growth and fruiting of snap beans. Leaf weights varied inversely with the temperature, but stem weights and numbers of nodes were not greatly affected by day temperature in the range of 75° to 95°F. Blossoming and pod set were similar at day temperatures of 75° and 85°F but were reduced at 95°F. When day temperature was 95°F, a 60°F night temperature resulted in increased blossoming and pod set compared to 80°F. When pods were harvested at marketable maturity, blossoming in bush beans was cyclic. Plants grown at a light intensity of 1900 foot-candles had a lower fresh and dry weight of leaves, stems, and pods, and fewer blossoms and pods set than plants grown at 2700 and 4000 foot-candles. Field experiments showed that planting dates after May 29 reduced the yield of pods in pole beans. Nitrogen level and row direction did not affect yield of pods in pole beans. Number of pods per plant in pole beans increased directly with the row spacing. Chemical sprays at blossoming caused no increase in yield of pods in pole beans, and only a slight increase in the yield of pods in bush beans. Differences in yields of pods between varieties of bush beans were due differences in the number of pods per plant. / Land and Food Systems, Faculty of / Graduate