Increase of Temperature at Apple Storage by Application of 1-MCP

The investigations should purify whether the temperature during apple storage can be increased by application of 1-MCP to decrease energy consumption and costs. The investigations were carried out over 2 years with the following treatments: Year 1: The apple cultivars 'Elstar, Elshof' and 'Gala, Must' were investigated. For both cultivars 3 different storage temperatures (1, 2 and 4 degrees C) with and without application of 1-MCP were examined. Each temperature and 1-MCP treatment was investigated both under CA-/ULO-conditions with 1.5% O-2 and 2% CO2 and in cold storage with normal atmosphere. Year 2: The apple cultivars 'Jonagold, Jonica' und 'Golden Delicious, Weinsberg' were investigated. For both cultivars 3 different storage temperatures (1, 2 and 4 degrees C) with and without application of 1-MCP were examined. Each temperature and 1-MCP treatment was investigated both under CA-/ULO-conditions with 1.5% O-2 and 3% CO2 and in cold storage with normal atmosphere. The influence of temperature, storage atmosphere and 1-MCP application on fruit firmness, soluble dry matter (sugar) and fruit acid was investigated on 6 dates (September to October in the first year) respectively on 5 dates (October to March) during the storage period. Following results were obtained: 1. In the first year storage temperature did not influence the content of soluble dry matter of both cultivars. Application of 1-MCP led to a less decomposition of soluble dry matter. In the second year the content of soluble dry matter decreased slightly with increasing temperatures. A clear positive effect of 1-MCP-application was not noticeable. Altogether an increase of storage temperature has no or only a small influence of the content of soluble dry matter. 1-MCP can slow down the decomposition of soluble dry matter. 2. An increase of storage temperature had no or only a small influence of fruit firmness. With increasing storage temperature fruit firmness decreased slightly. 1-MCP application led to a higher fruit firmness, especially during cold storage in normal atmosphere. In both years all cultivars showed a same or higher fruit firmness at 4 degrees C with 1-MCP application under CA-/ULO-conditions as at 1 degrees C without 1-MCP application under CA-/ULO-conditions. 3. An increase of storage temperature had no or only a small influence of the content of fruit acid. 1-MCP application under CA-/ULO-conditions reduced the decomposition of fruit acid. In both years usually all cultivars showed a same or higher content of fruit acid at 4 degrees C with 1-MCP application under CA-/ULO-conditions as at 1 degrees C without 1-MCP application under CA-/ULO-conditions.