C. Chervin et al., A HIGH-TEMPERATURE LOW-OXYGEN PULSE IMPROVES COLD-STORAGE DISINFESTATION, Postharvest biology and technology, 10(3), 1997, pp. 239-245
Short periods of elevated temperature under controlled atmospheres (Ck
) effectively control insect pests. Cold treatment is also an effectiv
e non-chemical disinfestation process. If synergistic effects can be f
ound by combining treatments, these may provide opportunities for cost
reduction. Tests were performed to evaluate the tolerance of Packham'
s Triumph pears (Pyrus communis L.) to a range of temperatures (30-40
degrees C) combined with low oxygen (O-2 <1 kPa). Treatment duration w
as 16-48 h and was followed by 1 month storage at 0 degrees C under ai
r. When held at 30 degrees C, pears withstood up to 30 h of hypoxia. A
fter cold storage, pears ripened slightly faster than controls but wer
e undamaged. A temperature of 35 degrees C induced slight skin brownin
g, and 40 degrees C resulted in substantial skin blackening. Some trea
tments were also tested on survival of lightbrown apple moth (LBAM), E
piphyas postvittana (Walker). All developmental stages were subjected
to either 16 h at 30 degrees C, or 16 h under hypoxia, or 1 month at 0
degrees C, or a combination of the three treatments. With all treatme
nts combined, all eggs, larvae and adults were killed. Only 4% of the
pupae produced adults and combined treatments led to an increase in pu
pa mortality of 38%. A combined treatment (tolerated by pears) consist
ing of 30 h at 30 degrees C under low O-2 plus 1 month cold storage un
der air, killed 100% of LBAM pupae, and 100% of 5th instar larvae of b
oth codling moth, CI clin pomonella (L.), and oriental fruit moth, Gra
pholita molesta (Busck). Implementation of such treatments would not r
equire substantial investments for fruit industries equipped with CA s
torage facilities. (C) 1997 Elsevier Science B.V.