Inhibitory effect of 1-MCP on ripening and superficial scald development in 'McIntosh' and 'Delicious' apples

'McIntosh' and 'Delicious' apple were treated with the competitive ethylene (C2H4) antagonist 1-methylcyclopropene (1-MCP), to evaluate its feasibilit y as a postharvest tool for use by the apple industry. The threshold concen tration of 1-MCP required to inhibit de novo C2H4 production and action was 1 mu l l(-1). 1-MCP treatment completely inhibited C2H4 production in appl es for 6-10 d at 20 degrees C following storage at 0 degrees C in air or co ntrolled atmosphere for 60 or 120 d. l-MCP-treated apples were significantl y firmer (13 to 20 N) than untreated apples following storage and post-stor age handling for 7 to 14 d at 20 degrees C. Total soluble solids of apples was not affected by 1-MCP treatment. Inhibition of total volatiles and prop ortional to-farnesene emanated by apples by 1-MCP treatment was parallel to the inhibition of C2H4 production by 1-MCP. Contents of proportional to-fa rnesene and its putative superficial scald causing catabolite, conjugated t riene alcohol, in the skin were reduced 60 to 98% by greater than or equal to 1 mu l l(-1) 1-MCP. Treatment with 1-MCP suppressed the incidence of sup erficial scald in 'McIntosh' and 'Delicious' apples by 30% and 90%, respect ively.