nontreated (control) apples were placed in storage. In
January, after 5 months of storage, the fruit were ana
lyzed for the intensity of scald. Apples harvested on
August 28 had 1.4% scald (1 of 70 fruit, with up to 1/8
of the surface being scalded). Apples harvested on
August 30 had no signs of scald. After being addition
ally stored at 20°C, still no browning was detected.
The intensity of scald in the treated apples harvested
after September 2 became higher than in control.
Therefore, the intensity of physiological processes
taking place in fruit plays an important role during
their treatment. The minimum content of chlorophyll
suggests that physiological processes are least intense.
For example, on September 21, apples become fully
ripe and ready to drop off the maternal tree. At this
stage, they reach harvest maturity, which is character
ized, in particular, by the minimum chlorophyll con
tent in their skin.
Similar experiments have been performed later.
However, fruit ripening occurred earlier than usual
(for 2–3 weeks) due to the unfavorable (hot) condi
tions in the following years. Thus, it was not possible to
treat apples on earlier dates. For this reason, there was
no clear understanding of the importance to consider
the intensity of physiological processes. Deviation in
the sum of active temperatures from its long term aver
age for the first decade of September in 2010, 2011,
2012, and 2013 was 676, 357, 419, and 319°C, respec
tively. It appears from this that it is not only physiolog
ical state of fruit based on the content of chlorophyll
that should be controlled but also weather conditions
of fruit growth and ripening.
These studies will allow us to develop a new con
cept for controlling fruit quality, which would take into
account ripening cyclicity (intensity and direction of
metabolic processes in fruits) making it possible to
determine an optimal date for harvesting, as well as
further treatments.
REFEREN