2017 ASHS Annual Conference

‘Honeycrisp’ apple (Malus x domestica Borkh.) fruit are very sensitive to injury under controlled atmosphere (CA) storage. The use of 1-methylcyclopropene (1-MCP) before and during air storage was evaluated as an alternative to avoid CA injury. To evaluate the effectiveness of multiple applications of 1-MCP on storage quality of air-stored fruit, fruit were treated with one (at harvest), two (harvest and after 1.5 months), or three (harvest, 1.5 months and 3 months) applications of 1-MCP prior to and during storage at 3 °C in 2015 and 2016. Indices, such as internal ethylene, aroma compounds, firmness, greasiness, incidence of CA injury, senescence breakdown and titratable acid of treated and non-treated fruit were analyzed at 1.5, 3, 4.5, 6 and 9 months of storage. The results showed that treatment with 1-MCP reduced the internal ethylene and aromatic compound production and delay senescence in apple cortex and greasiness on apple skin relative to untreated fruit but did not suppress the low level of 'CA injury’ (less than 5%) found in fruits held in air storage. Fruit treated with one, two and three doses of 1-MCP did not differ in these indices. Maturity stage of apples in terms of orchard and storage time is an important factor in the effectiveness of 1-MCP treatment. The data of two years confirm that a single dose of 1-MCP at harvest yields the maximum benefit in terms of quality retention.