التفاصيل البيبلوغرافية
| العنوان: |
Sunburn control in apple fruit |
| المؤلفون: |
Marais, Stephan J. S. |
| المساهمون: |
Wand, S. J. E., Theron, K. I., Stellenbosch University. Faculty of AgriSciences. Dept. of Horticulture. |
| بيانات النشر: |
Stellenbosch University |
| سنة النشر: |
2005 |
| المجموعة: |
Stellenbosch University: SUNScholar Research Repository |
| مصطلحات موضوعية: |
Apples -- Effect of temperature on, Orchards -- Management |
| الوصف: |
Thesis (MSc)--Stellenbosch University, 2005. ; ENGLISH ABSTRACT: Sunburn on apple and pear fruit results in large losses of export volumes in South African orchards. Producers estimate that losses due to sunburn are often about 10- 20%. Knowledge of temperature thresholds for sunburn as well as technologies available to manage sunburn is important to increase producer earnings. The effect of evaporative cooling on fruit surface temperature and sunburn was evaluated on 'Cripps' Pink', 'Royal Gala' and 'Fuji' apples as well as 'Forelle' pears. Evaporative cooling was effective in reducing fruit surface temperature by 0.6-3.7°C. Apple fruit under evaporative cooling treatments appeared to have acclimatised and had significantly higher surface temperatures when dry (0.9-4.7°C) than non-cooled fruit. This acclimitasing effect could be due to a modification of the cuticular wax layer. Futher trials are needed to investigate the cause of this acclimatising effect. The acclimatising effect was not found on 'Forelle' pears. Sunburn was reduced significantly only on 'Royal Gala' apples. Spraying 'Braeburn', 'Granny Smith', and 'Fuji' apples with reflective kaolin-based particle film (Surround WP) significantly reduced sunburn on 'Braeburn', 'Granny Smith' and 'Fuji' apple cultivars. Surround WP applications reduced leaf stomatal conductance and photosynthetic rate. Four applications of Surround WP with a commercial blower sprayer increased total soluble solids in 'Braeburn' . Four applications with a blower and five applications with a tower sprayer resulted in increased fruit size, higher flesh firmness, and lower percentage starch breakdown in 'Granny Smith'. Surround WP treatments slightly improved fruit colour in 'Granny Smith' apples. Futher trials are needed to establish whether Surround WP can,be reliably and economically removed from apple fruit and to evaluate the storage quality of fruit cleansed in this way. The effect of fruit surface temperatures (24°C, 30°C, 33-35°C, 40-43°C and 48-49°C) for increasing ... |
| نوع الوثيقة: |
thesis |
| وصف الملف: |
91 pages : illustrations; application/pdf |
| اللغة: |
English |
| Relation: |
http://hdl.handle.net/10019.1/50458 |
| الاتاحة: |
http://hdl.handle.net/10019.1/50458 |
| Rights: |
Stellenbosch University |
| رقم الانضمام: |
edsbas.622DEDC7 |
| قاعدة البيانات: |
BASE |