Potential and Problems of Film-wrapping Citrus in Florida1

Experimental and commercial storage and ship ping tests of film-wrapped citrus fruit were conducted the past 5 seasons. Fruit wrapped in film lost less water than waxed fruit, creating the potential for better arrival condi tion of export fruit and for extended storage of fruit to pro long the domestic marketing season. Film wrapping may allow 1 to 2 month holding periods with little quality loss at moderate temperatures (21 °C) and longer storage at lower temperatures. Unwaxed fruit should be used for film wrap ping since the 2 barriers of film plus wax can lead to exces sive off-flavor, particularly at temperatures higher than 21 °C. iFlorida Agricultural Experiment Stations Journal Series No. 5197. Proc. Fla. State Hort. Soc. 96: 1983. Promising prototypes of commercial wrapping machines have been tested in Florida packinghouses, but the integration of this machinery into a typical packinghouse line will require extensive or innovative packing line alterations since un waxed fruit of specific sizes is required for wrapping. If ade quately permeable films are used, cool coloring and fumiga tion can be accomplished in film-wraps. Handling and decay control methods have often been limiting factors in research and especially in commercial tests. Better handling and fungi cide application are needed to insure adequate decay control if film wrapping is to become a commercial practice. Plastic film wrapping can extend the shelf life of citrus fruit with the primary effect of reducing weight (water) loss and thereby deformation (1, 2, 5, 9, 11, 12). This report summarizes some previous film wrap work on citrus, pre sents new data on color changes and fumigation in film wraps, and evaluates problems and potentials for commercial use of film wrapping. Materials and Methods Data on weight loss and decay from grapefruit tests (1, 2, 3, 9, 12) over several years were summarized. Commercially harvested fruit were used in most of these tests and were commercially treated with TBZ [2-(4'-thiazolyl) benzimidazole] fungicide or by us with benomyl [(l-butylcarbamoyl)-2benzimidazole carbamic acid]. 'Robinson* tangerines (Citrus reticulata Blanco) were