Application of 1-MCP for Quality Preservation of Tomato (Lycopersicon esculentum) Seedlings during Long-distance Transportation
Increasing numbers of vegetable growers purchase their seedlings from specialized transplant producers. However, early yield reduction due to abnormal first fruit truss development was often observed after long-distance transportation of seedlings. 1-Methylcyclopropene (1-MCP), an inhibitor of ethylene-mediated reactions, is widely used for postharvest management. If ethylene accumulated in trailers causes such abnormal first truss fruit development, application of 1-MCP to seedlings may prevent such problems. To test this hypothesis, `Durinta' tomato seedlings with visible flower buds were placed in chambers for 4 days under one of the following conditions: 1) conventional transportation air temperature of 18 °C without 1-MCP, 2) 18 °C with 1-MCP, 3) 12 °C without 1-MCP, and 4) nonstored control. The target initial 1-MCP concentration was 1 μmol·mol-1 inside the chamber, and the concentration was estimated to reach 0.2 μmol·mol-1 after 96 h. Three weeks after transplanting, 81.3% of first trusses on the plants treated at 18 °C without 1-MCP exhibited an abnormal, delayed fruit development. Both 1-MCP application and 12 °C air temperature successfully reduced the symptom to 4.7% and 3.1%, respectively; not significantly different from the nonstored control (1.6%). The average first truss yield was the lowest for 18 °C without 1-MCP (223 g per truss), followed by 18 °C with 1-MCP (582 g), and was the greatest (609–637 g) for 12 °C without 1-MCP or the control. Ethylene accumulation was the primary cause of the delayed fruit development causing yield reduction. Application of 1-MCP during transportation was shown to prevent such undesirable yield loss, although lowering temperature was the most effective under the present experimental conditions.