d’Anjou pear fruit were surface sterilized with 100 mg of sodium hypochlorite per L and rinsed with tap water. Fruit were stem end inoculated with 2.0×106 spores L−1 of B. cinerea isolate
62 by dipping the stem ends into the inoculum to a depth of about 3 mm. Four replicate boxes containing 19 kg each were treated with 0, 10, 30, 50, 70, and 100 nL L−1 1-MCP. The source of 1-MCP was SmartfreshTM that was formulated as a 0.14% a.i. powder that liberates 1-MCP when added to 40 ◦C water. Fruit were treated inside a sealed cold storage room or sealed plexiglass chambers inside a controlled temperature storage room. Treatment was at 15 ◦C for 24 h. The atmosphere inside the room was circulated constantly with a fan. The ability of SmartfreshTM to release the stated amount of 1-MCP was confirmed for higher concentrations by flame ionization
gas chromatography as described previously (Chen and Spotts,2005). However, concentrations below 100 nL L−1 could not be verified accurately by this method, and the release rate was assumed to be linear at lower as well as higher concentrations.