A comparison of the effects of ethanol and higher alcohols for the control of superficial scald in apples

Abstract

SummaryÃSix alcohols (2–10 carbons) were packed with `Granny Smith' apples in sealed polyethylene bags (50.mm thickness) and stored at 08C. The rates of application were 0, 0.04, 0.08 and 0.16 mol kg–1 of fruit in year 1 and 0, 0.0075, 0.015 and 0.03 mol kg–1 in year 2. Although the bags were found to be permeable to the alcohols, sufficient remained in the bags to have marked effects on the fruit. All alcohols reduced the incidence of superficial scald. Good control of scald was achieved with ethanol at 0.03 mol kg–1 and higher rates. Lower application rates were effective with propan-1-ol, butan-1-ol and pentan-1-ol. }-Terpineol (10 carbons) was least effective. Ethanol produced no undesirable side effect but some of the other alcohols induced flesh browning at higher application rates. Ethanol, propan-1-ol, butan-1-ol and hexan-1-ol were compared for their effects on accumulation of }-farnesene and conjugated trienes. All alcohols reduced the concentration of }-farnesene and conjugated trienes at the end of storage. The concentrations of these two products fell as application rates of alcohols were increased.