RELATIONSHIPS BETWEEN ALPHA-FARNESENE, ETHYLENE PRODUCTION AND SUPERFICIAL SCALD DEVELOPMENT OF APPLES

Pre- and postharvest factors that affect development of superficial scald after cold storage of apples have been investigated, with emphasis on relationships of ethylene production to a-farnesene accumulation in fruit peel.
Weekly harvests of Cortland and Delicious apples resulted in increasing ethylene production rates and increasing accumulations of a-farnesene and conjugated trienes at harvest, but decreasing scald development after storage.
Cortland produced about twice as much ethylene as Delicious, and accumulated much more a-farnesene and conjugated trienes before harvest.
Ethephon applications to preclimacteric Cortland greatly increased synthesis of ethylene, a-farnesene, and conjugated trienes before harvest but either increased, decreased, or had no effect on scald development, depending on other conditions.
Bagging of Cortland apples for 6 weeks before harvest had no effect on ethylene, a-farnesene, or conjugated trienes, but increased superficial scald.
When Granny Smith were stored at 0, 4, 10.15 or 20C, changes in a-farnesene closely paralleled changes in ethylene production, but formation of conjugated trienes and development of superficial scald were related to temperature and not ethylene or a-farnesene.
Productions of both ethylene and a-farnesene were stimulated by intermittent warming during 0C storage, but superficial scald was suppressed by it.
A post-storage ethephon treatment of Cortland increased ethylene, a-farnesene and conjugated trienes but did not affect superficial scald.
The widely accepted association of a-farnesene and superficial scald development is discussed in light of these findings.

Physiological Basis of Postharvest Technologies

C.B. Watkins, C.L. Barden, W.J. Bramlage

https://doi.org/10.17660/ActaHortic.1993.343.33