|Hansen, James D|
Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2004
Publication Date: 5/1/2005
Citation: Drake, S.R., Hansen, J.D. 2005. Radio frequency to control codling moth in sweet cherries: Efficacy and quality. HortTechnology 14:1-5.
Technical Abstract: 'Bing' sweet cherries were each infested with codling moth larva, then exposed to various temperatures generated by radio frequency for differing times (50 deg C for 6 min., 51.6 deg C for 4 min., 53.3 deg C for 0.5 min., and 54.4 deg C for 0.5 min.). Insect mortality was evaluated 24 hrs. after treatment and fruit quality was evaluated after treatment and after 14 days of storage at 1 deg C. No survivors were found for the 50 deg C and 51.6 deg C treatments, but were observed, for the shorter duration 53.3 deg C and the 54.4 deg C treatments. Fruit color of non-infested cherries was darkened as temperature increased. Fruit color values (a and b) also changed as temperature increased, but this change would not be visible to the consumer, as hue values did not change with temperature. Stem color was severely impacted by heat generated by radio frequency. Stems in a warm water bath (38 deg C for 6 min.), a very mild heat treatment, darkened by 3.5 units (L values). When stems were exposed to higher temperature more darkening was evident. This darkening of the stems was accompanied with a reduction in green color, or significantly lower hue values. A change of one unit in color is visible to the human eye. Cherry firmness was reduced even with a mild heat treatment (38 deg C for 6 min.) and when cherries wee exposed to higher temperature, loss of fruit firmness was very significant. Subjective quality evaluations of both cherry fruit and stem indicated that increased heat reduced both visual fruit and stem indicated that increased heat reduced both visual fruit and stem quality; after 14 days of storage this quality loss was even more evident. The amount of pitting and bruising of cherries increased with temperature and again this increase was more evident after 14 days of storage.