Submitted to: Annual Meeting Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: March 27, 2006
Publication Date: July 10, 2006
Citation: Argenta, L.C., Fan, X., Mattheis, J.P. 2006. Responses of 'golden delicious' apples to 1-mcp applied in air and water. Annual Meeting Horticultural Society. Hort Science. 41:1052. Technical Abstract: 'Golden Delciuous' [Malus sylvestris var. domestica (Borkh.) Mansf.]apple fruit were treated with 1-methylcyclopropene (1-MCP) at 0.42, 4.2 or 42 mmol m**-3 in air at 20 deg C or 0.03, 0.3 or 3 mmol m**-3 in 20 deg C water. Fruit were held in air at 20 deg C for 25 days after treatment or stored at 0.5 deg C in air or in a controlled atmosphere (CA:1.5 kPa O2 + kPa CO2) for up to 6 months followed by 7 days in air at 20 deg C. Application of 1-MCP in air or water delayed the climacteric increase in respiration and ethylene production, and reduced softening, loss of acidity and peel color changes. Treatments applied as a water dip required a concentration 700 fold higher compared to gas treatment to induce similar physiological responses. Fruit responses to 1-MCP varied with treatment concentration with the maximum effects obtained at concentrations of 4.2 and 42 mmol m**-3 in air and 3 mmol m**-3 in water. 1-MCP treatment followed by storage in air was as effective as CA storage for retention of firmness and titratable acidity during 6 months storage. Simultanenous ethylene (55 mmol m**-3) and 1-MCP (42 mmol m**-3) treatment did not overcome 1-MCP effects on the inhibition of fruit ripening during holding at 20 deg C. Peel color changes were impacted less than retention of firmness and titrarable acidity for some 1-MCP treatments. 1-MCP treatment was less effective for slowing peel degreening when treated fruit were stored at 0.5 deg C. In one season, fruit treated with 1-MCP and stored in air at 0.5 deg C developed a peel disorder typified by a gray-brown discoloration that is unlike other disorders previously reported for this cultivar. Symptoms were observed the day fruit were removed from cold storage and no change in symptom appearance was observed during 7 days at 20 deg C.