As the population tends to urbanize, the potential consumer market of fresh produce becomes distant from the producing farm. This distance brings to growers and handlers the problems of how to keep their fresh products unspoiled after harvest and during transit period of shipping, and how they can be delivered to the specified destination without substantial deterioration. It is the common interest of fruit growers, shippers, wholesalers, and retailers that the shelf-life of fresh fruit be prolonged to increase sales. Sweet cherries are one of the important fruit crops in Utah. Being highly perishable, fresh sweet cherries have relatively short storage life after harvest . It is known that the approximate limit for the successful commercial storage of fresh sweet cherries is about 10 days to 2 weeks only. A practicable measure for extending this storage limit has to be established so that the market may have fresh sweet cherries over a longer season and also be able to balance the time of plenty and the time of scarcity. Furthermore, the Utah grown cherries may find new outlets in the distant market. Thus the benefit will be shared by the grower, the seller, and the consumer. Metabolic breakdown and fungal deterioration are the two important factors which cause the spoilage of fruits. Studies have shown that with many perishable produces, precooling -- the prompt application of refrigeration prior 2 to normal storage or transportation is the key to successful storage. Hydro -cooling treatment is considered to be advantageous especially in Utah, where high temperature and low relative humidity predominate during the harvest season of sweet cherries. Post-harvest chemical and packaging treatments of sweet cherries are possible approaches on ext ending the keeping quality of the fruits concerned. With some of the antifungal agents available today, the fungi which cause fruit decay might be successfully controlled. As a matter of fact, new fungicides, antifungal antibiotics, and packaging films are continuously developed by the industries in the United States. Appropriate combination of these newly developed materials with hydro-cooling followed by refrigerated storage, coupled with in vitro study of the effects of chemicals on fruit decay organisms, might lead to an improvement in the storage life of sweet cherries. It was with this idea in mind that experiments were conducted to study the effects of hydro-cooling, chemicals, and packaging treatments on preserving fresh sweet cherries and also in vitro effects of chemicals on certain fungi responsible for fruit deterioration.

In recent years there has been a considerable amount of work done on developing chemicals that would inhibit mold growth when applied to fresh fruit, and at the same time, be acceptable to man when taken orally. This would save many thousands of tons of fresh produce that are lost each year by spoilage before it ever reaches the consumer. Along with the development of new chemicals to inhibit mold growth there is a substantial amount of research being done on developing a packaging film that will prevent recontamination of the produce, at the same time allowing the passage of gasses into and out of the package to allow respiration of the fruit. During the present century much emphasis has been placed on growing certain varieties of fruit for our specific needs. It has been found that particular varieties are better for canning and that other varieties are better for freezing. With the release of atomic energy for peaceful use in 1933 by the United States Congress, a new era of food preservation was introduced. Men in the scientific fields believe it is possible to extend the shelf-life of fresh fruits without altering their physical condition to great extent. Many institutions have been awarded grants and contracts to work on various phases of food preservation with atomic energy. Utah State University was awarded a contract by the United States Army Quartermaster Corp to study the use of gamma radiation for extending the shelf-life of fresh produce. It was with this idea in mind that work for this thesis was conducted to study the effects of gamma radiation, fungicides, and packaging film on the microbial growth on certain varieties of strawberries and cherries. In addition, experiments were conducted using fungicides and packaging films in order to lower the dose of radiation necessary to prevent mold growth. In order for this method of preserving fresh fruit to become successful, new and more economical methods and techniques in handling the materials will have to be developed.