The influence of different concentrations of a film- forming antitranspirant (Wilt-Pruf ) on the transpiration rate of young apple trees (Ml06) was studied. One-year-old Mailing 106 trees were potted in 10.2 em (4 inch) metal pots. The plants were placed in a controlled environmental chamber during the study period. Sufficient reductions in water loss resulted with all concentrations of Wilt- Pruf with a 63 percent reduction at the highest concentration. Phytotoxicity was not observed though the higher concentrations imparted a sticky film to plants and they appeared to be lighter green at the end of the test. The effect of Wilt-Pruf on four-year old apple trees (Golden Delicious) was conducted in August 1977 at Utah State University Experimental Farm i n Farmington, Utah. The resistance to water vapor diffusion from the leaves was increased on both Wilt-Pruf treated irrigated and unirrigated trees, and water balance was improved, increasing leaf and stern water potential. The improved water balance of treated apple trees resulted in fruit size increase . The higher concentration of antitranspirant in both irrigated and unirrigated apple trees resulted in a higher leaf temperature than the irrigated control.

A 2 year study was conducted to investigate the influence of Atar on young apple trees. In 1996 concentrations of 0, 500, 1000, 2000, 4000, and 8000 ppm of Alar were applied to 'Golden Delicious', 'York Imperial' and 'Delicious' cultivars growing outside in gallon containers. / Ph. D.

Philosophiae Doctor - PhD / The domesticated apple (Malus x domestica Borkh.) has been distributed into diverse climatic conditions worldwide for commercial production of fruit. Apple trees need exposure to cold temperatures, referred to as chill unit (CU) accumulation during winter, in order for budbreak to occur promptly and uniformly after winter. In warmer production areas the application of dormancy breaking chemicals has enabled successful production of high chilling requiring apple cultivars in suboptimal environmental conditions. In the Western Cape region of South Africa it is common orchard practice to apply dormancy breaking chemicals after winter in order to stimulate vegetative growth. If this is not done prolonged dormancy symptoms (PDS) are experienced which include extended rest, less synchronised breaking of buds and reduced branching. An increasing awareness of both global warming and the negative effects associated with the use of chemical sprays (for both pest and disease resistance and growth regulation) has resulted in the need to breed cultivars better adapted to current and future environmental conditions. The breeding of new cultivars using conventional breeding methods is a time consuming process, especially in perennial tree species with a long juvenile phase such as apple. The implementation of marker-assistedbreeding (MAB) and selection (MAS) will enable the selection of favourable genotypes at a very early seedling stage. Although markers linked to genes involved in disease resistance for a variety of known apple pathogens have been identified and are already in use in breeding programs, the genetic determinants of dormancy related characteristics residing within the bud itself (endodormancy) are poorly understood. This hampers the genetic improvement of such characters. Although this study focused on time of initial vegetative budbreak IVB, there are various other characteristics that can be associated with dormancy, such as position and number of budbreak and budbreak duration. The unravelling of the genetic basis of complex traits such as dormancy, can be done through the construction of a genetic linkage map followed by the identification of genomic regions, known as quantitative trait loci (QTL), that can be ssociated with the trait of interest. This study involved the construction of genetic linkage maps for two mapping pedigrees where the low chilling requiring cultivar ‘Anna’ was used as common male parent in crosses with the higher chilling requiring ‘Golden Delicious’ and ‘Sharpe’s Early’. A third mapping pedigree, with ‘Golden Delicious’ as female parent and ‘Prima’ as male parent, was also included. Maps consisted of transferable SSR markers only, facilitating the alignment with the proposed apple reference map (Silfverberg-Dilworth et al., 2006) and adherence to the common LG numbering system now being used for apple genetic linkage maps (Maliepaard et al., 1998). A number of newly developed EST-SSR markers are reported, some of which are candidates for filling large gaps between adjacent SSR markers on the apple reference map. An interactive database was developed to successfully manage the large amount of data generated during this investigation. A selective mapping, or bin mapping strategy (Vision et al., 2000) was developed for two of the three mapping populations in order to facilitate the incorporation and positioning of newly developed markers onto existing genetic linkage maps. This involves the screening of new markers on a small subset of the population, drastically reducing the cost and time involved. Genetic linkage maps constructed allowed for the detection of 18 putative QTLs affecting the time of IVB. Four of these QTLs co-localize with previously identified QTLs. A QTL identified on LG 8 confirms a previously identified QTL (Segura et al., 2007), while one of the QTLs identified on LG 9 might coincide with a QTL identified on the corresponding LG 3 of the genetic linkage map constructed by Conner et al. (1998). Two QTLs identified on LG 10 might coincide with markers found to co-segregate with time of budbreak in an earlier study conducted by Lawson et al. (1995). An additional 14 QTLs involved in time of IVB have been identified. We proposed the testing of four markers in a validation study conducted on a second mapping pedigree derived from a cross between ‘Anna’ and ‘Golden Delicious’. These markers are CH04a12, CH04c06y, CH01h01 and A267. Not only do these markers show significant levels of association with the time of IVB, but segregation of parental alleles from the cultivar ‘Anna’ for two of these markers, CH04c06y and CH01h01, were found to be associated with the time of IVB in different genetic backgrounds. The identification of markers closely associated with time of IVB will facilitate the implementation of MAS in breeding programs in order to breed cultivars that are better adapted to local climatic conditions.

No description available.

Stellenbosch University. Faculty of AgriSciences. Dept. of Horticulture. / Thesis (PhD (Agric))--Stellenbosch University, 2006. / ENGLISH ABSTRACT: Market preferences for larger fruit have forced producers to adopt cultural practices that will ensure bigger fruit even if this comes at the expense of reduced total yields. In order to obtain acceptable fruit size there must be an adequate supply of photosynthetic carbon products especially during the cell division stage of fruit growth. Competition between fruits and between fruit and vegetative growth, as well as adverse climatic conditions, may limit the carbon supply to the fruits at this critical period and thus limit the final fruit size. Growers are showing renewed interest in the use of girdling or scoring in combination with the usual fruit thinning program to achieve growth control and increase fruit size. A new and milder chemical growth retardant, prohexadione-calcium (ProCa), is now also available for vegetative growth control of apple trees. [n this study, the effects of, and potential interaction between scoring, ProCa and fruit thinning were investigated, with respect to shoot and fruit growth, yield and photosynthetic capacity, in 'Royal Gala" 'Fuji' and 'Cripps' Pink' apple trees. ProCa decreased final extension shoot length in all three cultivars. Extension shoots were generally more sensitive than bourse shoots to scoring and ProCa. ProCa seems to be a more effective way of controlling shoot growth than scoring, with 'Fuji' and 'Cripps' Pink' being more sensitive than 'Royal Gala' to the application of ProCa. Scoring led to increased fruit growth rates during the first 40 days after full bloom (DAFB), and culminated in better fruit size at harvest. Scoring improved the total soluble solids concentration (TSS) of 'Fuji' and 'Cripps' Pink' compared to control and ProCa treatments. ProCa inhibited shoot growth effectively, but no evidence was found for improved carbon allocation to fruits and reproductive buds. Yield efficiencies of scored trees were significantly improved in all cultivars during the second season, due to better reproductive bud development after the first year of scoring. On 'Royal Gala' and 'Cripps' Pink', the efficiency of scoring to stimulate reproductive bud development on old and new spurs declined after 4 weeks after full bloom (WAFB). In 'Fuji', scoring later than I WAFB led to a decreasing positive response on old and new spurs. In contrast, reproductive bud development on long shoots increased with later scoring (6 and 8 W AFB) on all cultivars. It seems that the most beneficial time of scoring is 2-4 W AFB, as early as possible during the cell division stage offruit growth, but not before natural drop has occurred. The combination of early-season scoring and application of ProCa seems to hold potential for increasing carbon allocation to the fruit and improving fruit size and quality attributes. Scoring early in the season reduced photosynthetic capacity, and this reduction in carbon availability led to earlier cessation of shoot growth as well as shorter shoots. Later in the season, reduced fruit numbers led to a decrease in photosynthesis. The optimum temperature range for photosynthesis was found to adjust according to seasonal temperature variations. The harvest-induced reduction in sink strength changed stomatal sensitivity to higher temperature. Due to a reduced demand for carbohydrates by the plant, the maximum rate of photosynthesis (Amax) was reduced post-harvest. Following this reduction in sink strength and Am .. , stomata became more sensitive to high leaf temperatures, thus restricting water loss. Pre-harvest there was a strong demand for carbohydrates, therefore stomata were kept open at higher temperatures to ensure a high rate of C02 incorporation, but at a cost with regard to water use efficiency. The sharp increase in dark respiration (Rd) in leaves and fruit with an increase in temperature would mean that significant carbohydrate shortages could occur in trees during source limited periods early in the season, especially under warm weather conditions commonly experienced in the Western Cape region. / AFRIKAANSE OPSOMMING: Die effek van omgewings- en interne faktore op koolstofproduksie en -allokasie in appelbome (Malus domestlca Borkh.). Mark voorkeur vir groter vrugte forseer produsente om tegnieke te gebruik wat groter vrugte sal verseker selfs al beteken dit verlaagde totale opbrengste. Om aanvaarbare vruggrootte te bereik moet daar voldoende voorsiening van fotosinteties geproduseerde koolstofprodukte aan die vrug wees, veral gedurende die selverdelingstadium van vruggroei. Kompetisie tussen vrugte, en tussen vrugte en vegetatiewe groei sal die voorsiening van koolstof gedurende die kritieke stadium aan die vrug beperk en so vruggroote benadeel. Daar is dus hernude belangstelling in die gebruik van ringelering in kombinasie met die gewone vrug uitdunprogramme om groei te beheer en vruggrootte te verbeter. 'n Nuwe, sagter chemiese groeireguleerder, proheksadioon-kalsium (ProCa) is ook nou beskikbaar vir groeibeheer op appelbome. In hierdie studie is die effekte van, en moontlike interaksie tussen ringelering, ProCa en vruguitdunning ondersoek ten opsigte van loot- en vruggroei en opbrengs, sowel as die effekte op gaswisseling op 'Royal Gala', 'Fuji' en 'Cripps' Pink' appelbome. ProCa veroorsaak korter lote in aJ drie kultivars. Verlengingslote is meer sensitief as beurslote vir ringelering en ProCa. ProCa is effektiewer as ringelering om lootgroei te beheer, en 'Fuji' en 'Cripps' Pink' is sensitiewer as 'Royal Gala'. Ringelering lei tot verbeterde vruggroeitempos gedurende die eerste 40 dae na volblom en verbeterde vruggrootte by oes. Ringelering verbeter die totale oplosbare vastestotkonsentrasie (TOVS) van 'Fuji' en 'Cripps' Pink' in vergelyking met kontrole- en ProCa-behandelings, onderskeideHk. ProCa inhibeer lootgroei effektief, maar geen bewyse van verbeterde koolstomllokasie na vrugte en reproduktiewe knoppe is gevind nie. Opbrengseffektiwiteit van geringeleerde borne verhoog gedurende die tweede seisoen van ringelering weens beter reproduktiewe knopontwikkeling. Ringelering later as 4 weke na volblom (WNVB) is minder effektief om reproduktiewe knopontwikkeling op ou en nuwe spore in 'Royal Gala' en 'Cripps' Pink' te stimuleer. Die positiewe effek van ringelering op reproduktiewe knoppe op 'Fuji' verminder sodra dit later as I WNVB gedoen word. Op langlote het 'n laat ringelering (6 en 8 WNVB) die beste effek op reproduktiewe knopontwikkeling. Die mees voordelige tyd om te ringeIeer was 2-4 WNVB, so vroeg as moontlik gedurende die selverdelingstadium van vruggroei, maar nie voor natuurlike vrugval voltooi is nie. Die kombinasie van vroei! ringelering en die toediening van ProCa het potensiaal om koolstofallokasie na die vrug te verbeter, met die gepaardgaande verbetering in vruggrootte en -kwaliteit. RingeJering vroeg in die seisoen inhibeer fotosintese en hierdie verlaging in koolstof beskikbaarheid het tot gevolg dat lootgroei vroei!r gestaak word. Later in die seisoen veroorsaak verlaagde vruggetalle 'n afname in fotosintese. Die optimum temperatuur vir fotosintese verander na gelang van heersende lugtemperature. Die oes-geinduseerde verlaging in sinksterkte verander stomatale sensitiwiteit vir hoo temperature. Weens 'n verJaagde aanvraag vir koolhidrate deur die plant word fotosintese verlaag na-oes. Weens die verlaging is stomata sensitiewer vir hoer temperature en beperk dus waterverlies. V oor oes is daar 'n hoo aanvraag na koolhidrate dus word stomata oop gehou selfs by hoe temperature ten koste van watergebruiksdoeltreffendheid. Die skerp styging in donker respirasie in blare en vrugte met 'n verhoging in temperature sal beteken dat koolhidraat-tekorte kan ontstaan in bome gedurende die bron-beperkte periodes vroeg in die seisoen, veral onder warm toestande 500S wat algemeen ervaar word in die Wes Kaap.

2008 – 2009 metais LAMMC SDI obelų pomologiniame sode atlikti introdukuotų obelų veislių su B. 396 poskiepiu tyrimai, tikslu – ištirti biologines ir ūkines savybes. Tyrimų metu nustatyta vaismedžių žydėjimo tarpsniai (žydėjimo pradžia, masinio žydėjimo pradžia ir pabaiga, žydėjimo pabaiga); vaismedžių augumas (medžio aukštis, vainiko skersmuo, kamieno skersmuo, vainiko projekcijos plotas); vaismedžių derlius, vaisių paskirstymas į klases pagal skersmenį, vaisių skynimo laikas, laikymosi pabaiga, vaisiaus masė, kokybė (išvaizda, patrauklumas, bendra kokybė balais), cheminė sudėtis (tirpios sausosios medžiagos, sausosios medžiagos, titruojamasis rūgštingumas), sulčių išeiga, odelės ir minkštimo tvirtumas. Įvertinus tirtų požymių visumą, nustatyta, kad Lietuvos sąlygomis geriausios kokybės vaisius su B.396 poskiepiu išaugina veislės ‘Aldas’, ‘Vanda’, ‘Rosana’ ir ‘Rubinola’ vaismedžiai. Darbo apimtis: puslapiai 39, lentelės 6, paveikslų 12, naudotos literatūros šaltiniai. / The research was carried out at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry in 2008–2009. The aim of this study was to evaluate the biological and economical characteristics of the introduced apple cultivars on B.396 rootstock. The following characters of apple trees were established: blooming periods (opening of the first blossoms, beginning/end of the full bloom, the end of blooming), vigour of the trees (height, diameter of a crown, diameter of a trunk, area of a crown projection); apple yield, distribution of fruits to classes according to diameter, harvesting time, storage life, fruit size, quality (appearance, taste, general quality evaluation) and chemical composition (soluble solids, dry matter, titratable acidity), juice output, substance of skin and flesh. ‘Aldas’, ‘Vanda’, ‘Rosana’ and ‘Rubinola’ according biological and economical characteristics is the best among other investigated cultivars on B.396 rootstock in Lithuanian climatic conditions. Work size: pages 39, tables 6, pictures 12, references 44.

Studies were conducted under greenhouse conditions to investigate the relative efficiency of urea absorption by 1-month-old peach and apple leaves. A 4 percent solution of urea containing .1 percent Colloidal X-77 was applied to the leaves in the form of a fine spray. To aid in this procedure, an improved micros prayer with a l milliliter capacity was developed. Accuracy of the sprayer was ± l percent. Under greenhouse conditions, the upper and lower surface of peach and apple leaves absorbed urea. More urea was absorbed through the lower than the upper surface. Peach lower surface absorbed nearly as much as apples after 48 hours. In another experiment using a controlled environmental growth chamber, the effect of temperature, humidity and surfactant (Colloidal X-77) on absorption of 1 percent 14C urea solution by apple and peach leaves were studied. Uptake was again much greater from the lower surface of the leaves as compared to the upper surface. Low relative humidity (25 percent) reduced absorption substantially. High temperature (24 centigrade) under low humidity (25 percent) decreased absorption. Uptake was increased substantially with the high temperature (24 centigrade) and relative humidity (85 percent). Peach leaves were more sensitive to temperature than apple, in regard to the amount of absorption that occurred. In peach, a 5 to 10 fold decrease in absorption was observed when the temperature was lowered from 24 to 10 centigrade. Surfactant increased absorption through the lower surface within a short period after application but decreased it afterwards. Urea absorption through 45-day-old leaves at 85 percent relative humidity and 24 centigrade indicated that within 48 hours over 90 percent of the urea applied to lower surfaces was absorbed by both species of leaves. A cuticular permeability experiment indicated that upper cuticles from both species of leaves were permeable to urea. It seemed that permeability of peach cuticle increased with time at the higher temperature. After 48 hours, the amount of urea, which penetrated through the peach cuticle at 24 centigrade, was 2.7 fold as much as at 10 centigrade. Urea absorption within 1 hour and translocation after 4 hours were observed under favorable conditions (24 centigrade and 85 percent relative humidity). Radioautograms of 14C urea treated apple and peach leaves indicated that the 14C urea and/ or its metabolites had been translocated within a large portion of the leaf within 8 hours after application. Studies were also performed on these species utilizing microradioautography and histochemistry techniques. Microradioautograms prepared from treated leaf sections demonstrated that adsorption and absorption of radioactive urea occurred on the epidermal hairs of apple leaves. Urea entry occurred in both apple and peach leaves as evidenced by high activity of 14C compounds within the leaf tissue. Microscopic observations of freshly sectioned leaves of both apple and peach demonstrated a relatively high amount of pectinaceous substances between the cell walls and especially the bundle sheath and bundle-sheath extension cells. Pectinaceous substances were present more in apple cuticle than in peach cuticle.

Les pommiers sont la cible de nombreux ravageurs et maladies fongiques, à l’origine de pertes économiques importantes. Les agriculteurs sont dans l’obligation de traiter les micro-organismes responsables des maladies fongiques, notamment à l’aide de pesticides. Les produits phytosanitaires sont aujourd’hui très controversés. Ainsi, les pouvoirs publics, français et européens, contrôlent leur emploi par de nombreuses règlementations. Par conséquent, il apparaît nécessaire de proposer une alternative peu rémanente permettant de contrôler le développement fongique. L’objectif de cette thèse est d’évaluer l’efficacité d’une alternative innovante basée sur l’emploi d’eau chargée en ozone contre quatre espèces fongiques à l’origine des principales maladies du pommier : Venturia inaequalis, Botrytis cinerea, Neofabraea alba et Phytophthora syringae. Dans un premier temps, ce travail de thèse a permis de vérifier l’action anti-fongique de l’ozone sur les suspensions de spores des quatre espèces fongiques ainsi que sur différents stades de développement des spores de V.inaequalis. Il a été mis en évidence une différence de sensibilité selon l’espèce et le stade de développement considérés. Par ailleurs, l’altération de la membrane sous l’action de l’ozone a été observée par plusieurs expérimentations : quantification du degré de peroxydation des phospholipides membranaires, observations des spores au Microscope Electronique à Balayage et au Microscope Optique après colorations. Dans un second temps, l’effet de l’eau chargée en ozone a été évalué sur des jeunes plants de pommiers préalablement contaminés par les spores de V.inaequalis. Cette étude a confirmé l’action anti-fongique de l’eau chargée en ozone. Il a également été observé l’importance des quantités d’eau et d’ozone apportées qui doivent être maîtrisées pour optimiser l’efficacité du traitement. Ces résultats permettent de valider la candidature de l’ozone comme fongicide alternatif à l’emploi de produits phytosanitaires. Les modalités d’application devront faire l’objet de recherches supplémentaires en vue du transfert de la technologie du laboratoire au verger. / Apple trees are the target of a lot of pests and fungal diseases, responsible for many economic losses. Farmers treat these micro-organisms mainly with pesticides. Plant-protection products are today very controversial. French and European authorities control their use by means of numerous regulations. Therefore, an alternative solution with a low remanence must be found in order to limit fungal diseases. The aim of this thesis is to evaluate the innovative process efficiency based on the use of ozonated water against four fungal species: Venturia inaequalis, Botrytis cinerea, Neofabraea alba and Phytophthora syringae. Firstly, this work of thesis verified the ozone antifungal action on spores suspensions of the four fungal species and on different stages of development of V.inaequalis spores. According to the species and stages of development considered, a difference of sensibility was detected. Moreover, alteration of the membrane, due to ozone action, was observed thanks to several experimentations: quantification of phospholipids peroxidation, spore observations with Scanning Electron Microscopy and with Optical Microscopy after staining. Secondly, the ozonated water effects on seedlings previously contaminated by V.inaequalis spores were evaluated. This study confirmed the anti-fungal action of water containing ozone. It was also observed the importance of the water and of ozone quantities supplied. These quantities must be controlled to optimize the antifungal action of the treatment. These results validated the ozone application as a fungicide alternative of use of pesticides. Additional researches will be made concerning the treatment modalities: the aim is to transfer the technology from the laboratory to the orchard.

Philosophiae Doctor - PhD / The domesticated apple (Malus x domestica Borkh.) has been distributed into diverse climatic conditions worldwide for commercial production of fruit. Apple trees need exposure to cold temperatures, referred to as chill unit (CU) accumulation during winter, in order for budbreak to occur promptly and uniformly after winter. In warmer production areas the application of dormancy breaking chemicals has enabled successful production of high chilling requiring apple cultivars in suboptimal environmental conditions. In the Western Cape region of South Africa it is common orchard practice to apply dormancy breaking chemicals after winter in order to stimulate vegetative growth. If this is not done prolonged dormancy symptoms (PDS) are experienced which include extended rest, less synchronised breaking of buds and reduced branching. An increasing awareness of both global warming and the negative effects associated with the use of chemical sprays (for both pest and disease resistance and growth regulation) has resulted in the need to breed cultivars better adapted to current and future environmental conditions. The breeding of new cultivars using conventional breeding methods is a time consuming process, especially in perennial tree species with a long juvenile phase such as apple. The implementation of marker-assistedbreeding (MAB) and selection (MAS) will enable the selection of favourable genotypes at a very early seedling stage. Although markers linked to genes involved in disease resistance for a variety of known apple pathogens have been identified and are already in use in breeding programs, the genetic determinants of dormancy related characteristics residing within the bud itself iii (endodormancy) are poorly understood. This hampers the genetic improvement of such characters. Although this study focused on time of initial vegetative budbreak IVB, there are various other characteristics that can be associated with dormancy, such as position and number of budbreak and budbreak duration.

The central idea of this project named “My way home” (the project’s name was inspired by Karel Václav Rais’s poem of the same name) is the work with the memory of a landscape. The project concerns a 700-metre-long area which is part of what used to be a road near Stráž nad Nežárkou. First of all, I try to return the road its original purpose. Also, I try to find out its historic foundation. Finally, I try to return the road its integrity. The road used to go from the village of Dvorce to the now cancelled Gabler’s mill (house number 98) in Stráž nad Nežárkou. The Diploma also includes an observation of the changes of the landscape near the village. The Diploma itself consists of three phases: The road, apple trees, The object.