SCALD AND ITS CONTROL: THE NORTH AMERICAN SITUATION

Incidence and severity of scald in apples and pears are cultivar- and strain- dependent and subject to seasonal and regional variation.
Reported scald susceptibility for a given cultivar may vary due to differences in climate (e.g. preharvest air temperature), harvest maturity and storage duration.
Diphenylamine (DPA) and ethoxyquin (EQ, 6-ethoxy-1,2,-dihydro-2,2,4-trimethyl quinoline) are used in apples and EQ in pears for scald control.
Highest label rates (2000 ppm DPA or 2700 ppm EQ) are commonly applied to ensure maximum scald control.
Recent global concerns about the effects of chemicals on human health and the environment are creating uncertainty over the continued use of DPA and EQ. Work is currently underway to search for minimal effective rates and reliable methods for scald prediction and non-chemical scald control.
Very low levels of O2 have been used commercially to control scald in apples (British Columbia: 0.7% O2; Washington: 1.0% O2) and in pears (Oregon: 1.0% O2). Re-registrations of DPA for use on apples and EQ for use on pears are currently in progress.
EQ will not be re-registered for apples.

International Symposium on Pre- and Postharvest Physiology of Pome-fruit

O.L. Lau

https://doi.org/10.17660/ActaHortic.1993.326.23