TITLE:
Mechanical Shaking and Baling of Balsam Fir Trees Influence Postharvest Needle Senescence and Abscission
AUTHORS:
Ernest A. Korankye, Rajasekaran R. Lada, Samuel K. Asiedu, Claude Caldwell
KEYWORDS:
Shaking, Baling, Ethylene, Volatile Terpene Compounds, Needle Loss, Thigmomorphogenesis
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.3,
February
12,
2018
ABSTRACT: This study investigated
the influence of both shaking duration and number of trees per bale on
postharvest needle characteristics such as percentage needle loss, needle
retention duration and explored the physiological roles of endogenous ethylene
and volatile terpene compounds (VTCs).
To accomplish these objectives, 25 six-year-old trees were detached
and exposed to a range of shaking durations (0 to 60 sec.), and 30 six-year-old detached trees were
exposed to baling treatments from 0 to 5 trees. Response variables measured
were percent needle loss, needle retention duration, average water use,
ethylene and volatile terpene compound evolution. Trees shaken for 60 seconds
lost 16%
less needle compared to control, which was consistent with the decrease in
percent needle loss with increasing shaking duration. Baled trees lost 13% more
needles compared to control, but percent needle loss was observed to decrease
with increasing number of trees in a bale. These trends corresponded with
increasing ethylene and VTC evolutions, where the longer the shaking duration
or larger number
of trees in a bale, the higher the ethylene and VTC evolutions. One can
therefore draw inference that mechanical perturbation as a result of shaking
and baling induce biosynthesis and regulation of ethylene and VTC in balsam fir
trees in an effort to regulate postharvest needle abscission.