Current APHIS protocols allow that if a given
cold treatment temperature is breached after having
achieved a FCT of, e.g. B1.1°C that the
treatment may continue based on the next
(higher) temperature (e.g. B1.67°C), as long as
FCT of the fruit did not exceed the next higher
temperature and the time is extended to meet the
requirements of the treatment at the new temperature
(e.g. to 14 days at B1.67°C). However, if the FCT of 2.2°C is exceeded at any time during the
treatment, the treatment must then start over again
or the shipment is deemed to have not met the
‘minimum’ treatment protocol. Our results show
that transient temperature spikes (in excess of
2.2°C) of the type tested in this study will not
compromise the efficacy of the treatment and that
no additional days of treatment are needed if the
temperature is subsequently returned to the (lower)
temperature and the treatment allowed to continue
for the remaining required days of treatment. We
do not have information on the length of time that
the temperature breach may last during a treatment
or the highest temperature that could be achieved
without requiring additional days of treatment.
These questions are outside the scope of this study
but are clearly warranted and necessary if adjustments
to cold treatments for a variety of conditions
are desired. However, we do recommend that
in-transit cold treatments of ‘Sharwil’ avocado
which experience temperature breaches of no more
that 4.2°C (for no longer than 3 h) at day 6–9 (after
having previously attained a designated FCT) be
certified as ‘successfully treated’ as long as temperature
and duration regimes are resumed and completed.