Der Text beschreibt die Idee hinter dem PHP Extension and Application Repository (PEAR), und die Wartung und Nutzung von PEAR.

Thesis (MScAgric)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Delayed foliation is commonly observed in apple and pear producing countries with warm and/or short winter climates, resulting in less synchronised budburst, of fewer buds and reduced yield. Applications of rest-breaking agents minimise the symptoms of delayed foliation. According to chilling models used in fruit producing areas of the world, the climate of South Africa is not suitable for deciduous fruit production, however fruit has been successfully produced here for a long time. This study aimed to quantify the effects of freezing temperatures, different chilling temperatures and the period of chilling, to obtain a better knowledge of bud dormancy release on apple and pear shoots. The chilling period was the most important factor influencing the progression of dormancy. While in some cases the chilling temperature and the freeze treatment effects were significant, the contribution to differences in the progression of dormancy was negligible. Our findings indicate that currently used chilling models should emphasise the time of exposure to low temperatures more than the difference in temperatures between I to ro-c. The South African apple and pear industry made good progress in moving towards high density plantings, but large variation in soil types, non-optimum growing conditions, replant situations and a lack experience with dwarfing rootstocks limited further development. However, there is sti II an urgency to obtain higher early yields of good quality fruit applying the most efficient production practices. We aimed to quantify the field performance of locally available apple and pear rootstocks, in particular from data outside of previously reported local trials, as well as early production of newly planted trials. Information obtained form the industry indicates that BPI and BP3 are the preferred pear rootstocks. From production records of 'Packham's Triumph' pears, it appeared that BP3 and OHxF97 produced the best yields compared to the other rootstocks. Production of 'Doyenne du Cornice' was the best on QA and BP3. In newly planted 'Rosemarie', 'Flamingo', and 'Forelle' trials, different rootstocks were evaluated. 'Rosemarie' showed indications 01 incompatibility with QA and QC5 I, but on BPI and QA with a 'Beurre Hardy' interstock produced good initial yields although BPI induced slightly larger trees. 'Flamingo' on QA and QC51 produced the best yields. 'Forelle' on BPI, BP3, and QA produced similar yields up to the 4th leaf. For apples M793 seems to be the preferred rootstock in the South African industry. From production records of 'Golden Delicious' and 'Granny Smith' apples, it appeared that M793 and MM 106 produced the best yields when compared to Seedling rootstock. In a 'Cripps' Pink' trial, MMI09, M793 and M25 were more vigorous than M7, MMlll and MMI06. MMI06 was cumulatively, over four years from planting, the most yield efficient, although no consistent trend regarding fruit quality was observed between the rootstocks evaluated. / AFRIKAANSE OPSOMMING: Vertraagde bot word algemeen opgemerk in appel en peer produserende lande met n' warm enlof kort winter klimaat, wat veroorsaak dat bot van minder knoppe, meer ongelyk plaasvind en gevolglik lei tot swakker opbrengste. Toediening van rus-breek middels beperk die simptome van vertraagde bot. Volgens koue modelle wat in vrugte produserende areas in die wereld gebruik word, is Suid Afrika se klimaat nie geskik vir die verbouing van sagtevrugte nie alhoewel sagtevrugte al vir n lang tyd met groot sukses hier verbou word. Hierdie studie is daarop gemik om die effek van vries temperature, verskillende koue temperature en die periode van koue op die vrystelling van dormansie op knoppe van appel en peer lote te kwantifiseer. Die peri ode van koue was die mees belangrikste faktor wat die ontwikkeling van dormansie beinvloed het. In sommige gevalle was die effek van die koue temperature betekenisvol, maar die bydrae tot die verskille in die ontwikkeling van dormansie was weglaatbaar klein. Ons bevindinge dui aan dat die huidige koue modelle wat gebruik word, meer klem moet le op die periode van blootstelling aan koue as aan die effek van verski llende temperature tussen 1 en 10°e. Die Suid Afrikaanse appel en peer bedryf het goeie vordering in die beweging na hoe digtheid aanplantings gemaak, maar groot verskille in grond tipes, sub-optimale groei toestande, herplant probleme en n' tekort aan ondervinding met dwergende onderstamme het verdere ontwikkeling beperk. Ten spyte hiervan is daar steeds n' dringendheid om hcer produksies, van goeie kwaliteit vrugte so vroeg as moontlik te kry deur die toepassing van die mees effektiewe produksie praktyke. Ons het gepoog om die prestasie van plaaslik beskikbare appel en peer onderstamme te kwantifiseer, in besonder deur data wat nog nie van tevore oor verslag gedoen is nie en ook deur te meld van vroee produksies op nuut aangeplante proewe. lnformasie uit die bedryf het aangedui dat BP 1 en BP3 die voorkeur peer onderstamme is. Deur na die produksie geskiedenis van 'Packham's Truimph' pere te kyk kom dit voor of BP3 en OHxF97 die beste produksies in vergelyking met die ander onderstamme gelewer het. Die produksie van 'Doyenne du Com ice' was die beste op QA en BP3. In nuut geplante 'Rosemarie', 'Flamingo', en 'Forelle' pro ev e was verskillende onderstammc gecvalueer. 'Rosemarie' het tekens van onverenigbaarheid getoon met QA en Q 51, maar op BP 1 en QA met n 'Beurre Hardy' tussenstam het 'Rosemarie' goeie aanvanklike opbrengste gel ewer, al was bome op BP 1 effens grater. 'Flamingo' op QA en QCS 1 het die beste opbrengste gelewer. 'Forelle' op BP 1, BP3, en QA het ongeveer ewe veel tot die 4dc blad geproduseer. By appels is M793 die voorkeur onderstam van die Suid-Afrikaanse appel bedryf. M793 en MM 106 gee beter opbrengste as Saailing onderstam wanner die produksie geskiedenis van 'Golden Delicious' en 'Granny Smith' appels evalueer word. In n' 'Cripps' Pink' proefwas MMI09, M793 en M2S meer groeikragtig as M7, MMlil en MMI06. MM I 06 het kumulatief meer geproduseer en was ook meer produsie doeltreffend tot en met die 4de blad na plant. Daar was egter geen konstante neiging rakende vrug kwaliteit tussen die verskillende onderstamme wat getoets is nie.

Jackson County, Oregon is noted for the production of high quality pears. It is the fourth leading pear producing county in the United States and is the number one producer of winter pears. This thesis analyzes in detail the many aspects of the pear industry in the county. Climate, soils, topography, and progressive growers have been the main localizing factors. The study revealed that 200 growers produce the average annual total of three million boxes of pears on 9940 acres of bearing orchards. The pears are prepared for market in 12 packing houses and two canneries. The industry has a direct impact on the county of $15,000,000. The problems confronting the industry are caused by physical and biological factors. Spring frosts and hail damage are problems imposed by the climate. Pear Blight, Pear Decline, and Pear Scab are the main diseases. Insect pests such as the Pear Psylla and the Codling Moth must also be combatted. Urban encroachment has not yet been a serious problem in the county. The future for the industry appears to be stable, with little change in acreage. The fruit gift box industry will become of increasing importance, thus creating further emphasis on producing winter pears. / Graduation date: 1963

Yeast biocontrol agents that were applied to 'Bose' and 'Anjou' pears in the field up to three weeks prior to harvest were found to survive on the fruit at high population levels on both pear varieties. Cryptococcus infirmo-miniatus, Cryptococcus laurentii, and Rhodotorula glutinis maintained populations averaging 5 x 10��� cfu/fruit for three weeks. Candida oleophila had high initial populations, but the population size quickly declined to levels similar to the total yeast populations on untreated fruit. After a storage period of 2-4 months, fruit that were treated with C. infirmo-miniatus three weeks before harvest showed significantly lower incidence of decay at wounds than did untreated fruit. Combinations of biocontrol agents with reduced rates of the postharvest fungicides captan and thiabendazole were effective in reducing incidence and severity of blue mold decay caused by Penicillium expansum on 'Bosc' pears. Calcium chloride was also effective in combination with some biocontrol agents. Chitosan caused reductions in decay when used alone, but not when combined with most biocontrol agents. The compounds L-asparagine, L-proline, and 2-deoxy-D-glucose were not consistently effective either alone or combined with biocontrol agents. Storage of 'Bosc' and 'Anjou' pears in atmospheres with carbon dioxide concentrations of 12% or 20% for up to six weeks significantly reduced incidence and severity of gray mold decay caused by Botrytis cinerea, but decay was not reduced when the atmospheres was only 3% CO���. In contrast, the 12% or 20% CO��� atmospheres did not have significant effects on decay caused by P. expansum. Use of the biocontrol agents C. infirmo-miniatus, C. laurentii, or R. glutinis led to reductions in decay in all atmospheres, with C. infirmo-miniatus being the most consistently effective. The biocontrol products BioSave-110 (EcoScience Corp.) and Aspire (Ecogen Corp.) were less effective than the yeasts C. laurentii, R. glutinis, and C. infirmo-miniatus which were grown in the lab. / Graduation date: 1999

Graduation date: 1990

Thesis (Ph. D.)--Washington State University, August 2008. / Includes bibliographical references.

The purpose of this study was to determine the phenolic constituents of Bartlett pears and to evaluate the processed samples for extent of discoloration and to relate the two. Pears were obtained from three orchards in the Medford area and from three orchards at each of the three elevations, 500, 1700, and 2300 feet, in the Hood River area. Four replications were made. Values for the total phenol content of the pears ranged from 54.3 to 120.8 milligrams per 100 grams of fresh pear tissue. The leuco-anthocyanin content of the pears ranged from 6.4 to 21.0 milligrams per 100 grams of pear tissue and the flavanol content ranged from 11.3 to 44.8 milligrams per 100 grams of pear tissue. The pH of the pears ranged from 3.70 to 4.09. Color of the pears processed for twenty-five, thirty-five and forty-five minutes was measured. Those pears with the highest concentration of total phenols, leuco-anthocyanin and flavanols and the lowest pH were the pinkest when overprocessed. Pears which were least pink were among the lowest in total phenols, leuco-anthocyanin and flavanols and had the highest pH values. However, among the remaining fruits, the pinker pears were not necessarily those with the higher total phenolic content or the lower pH values. / Graduation date: 1963

Graduation date: 1931

Graduation date: 1931