Heat injury thresholds in apples measured using chlorophyll fluorescence are influenced by orchard heat reduction technologies
dc.contributor.author | Wand S.J.E. | |
dc.contributor.author | Van Den Dool K. | |
dc.contributor.author | Smit A. | |
dc.contributor.author | Steyn W.J. | |
dc.date.accessioned | 2011-05-15T15:56:25Z | |
dc.date.available | 2011-05-15T15:56:25Z | |
dc.date.issued | 2008 | |
dc.description.abstract | Chlorophyll fluorescence (Fv/Fm) was used to investigate thresholds of heat injury in apple fruit grown under orchard heat reduction technologies, i.e. evaporative cooling (EC) and 20% black shade netting. Picked apples were exposed to oven temperatures of 35, 40, 45, 50 or 55°C for two, four, six or eight hours and fruit surface temperature (FST) and Fv/Fm measured immediately following heat treatment, and after a 12-hour recovery period. In all trials, permanent injury occurred at 48-53°C FST irrespective of duration, with permanent injury possible at 42-47°C depending on duration. Non-EC 'Cripps' Pink' were more resistant to heat injury at 45°C than EC fruit. Fruit from three cultivars under netting ('Royal Gala', 'Fuji', and 'Cripps' Pink') had lower Fv/Fm at 43°C than non-netted fruit. The results indicate clear temperature thresholds for heat injury, with duration of exposure and orchard acclimation responses becoming important at sub-lethal surface temperature ofc.45°C. | |
dc.description.version | Conference Paper | |
dc.identifier.citation | Acta Horticulturae | |
dc.identifier.citation | 772 | |
dc.identifier.issn | 5677572 | |
dc.identifier.uri | http://hdl.handle.net/10019.1/9836 | |
dc.subject | Malus x domestica | |
dc.title | Heat injury thresholds in apples measured using chlorophyll fluorescence are influenced by orchard heat reduction technologies | |
dc.type | Conference Paper |