The prevention of storage disorders in sweet cherries resulting from mechanical damage was investigated. Pre- and post-harvest treatments were applied to modify fruit texture, fruit composition and fruit desiccation in storage. The effects of the treatments applied were related to fruit susceptibility to the incidence of fruit bruises, surface markings and surface pitting. The application of calcium in the form of pre-harvest sprays or post-harvest dips decreased mechanical damage expression. Warm fruit was less susceptible to mechanical injury than cold fruit early in the storage period but fruit temperature had little effect after 8 days of cold storage. Similarly, high storage temperatures enhanced pitting development early in the storage life but storage temperatures had negligible effect after 8 days. A delay in 0℃ storage prior to bruising greatly reduced the susceptibility of cherries to mechanical injury. Fruit was most resistant to mechanical damage after 8 days in 0°C. The development of fruit symptoms in response to impact was enhanced by rough surfaces. Slowly applied compressive forces resulted in low incidences of injury symptoms. Fruit firmness and bioyield values were increased with mesocarp calcium from preharvest sprays and post-harvest dips, but did not show consistent relationships to the susceptibility of fruit to mechanical damage. Weight loss enhanced by low relative humidity increased the rate of development of damage but did not influence the total damage incidence. Soaking fruit in water or fungicide solution increased damage expression in storage. Less mature and intermediate maturity fruit were more susceptible to mechanical injury than were the most mature fruit. Fruit with relatively high alcohol insoluble solids content associated with pre-harvest gibberellic acid sprays or advanced maturity fruit had reduced susceptibility to mechanical damage. Large fruit was less susceptible to mechanical damage and had higher alcohol insoluble solids content than did small fruit. High levels of fruit nitrogen were associated with high susceptibility to mechanical damage. A great many factors were found to modify fruit susceptibility to surface disorders resulting from mechanical damage. This provides a great flexibility to producers and marketing agents to minimize fruit losses due to the effects of rough handling. / Land and Food Systems, Faculty of / Graduate

No description available.

The structure of the Royal Anne cherry cuticle (Prunus avium L.) and its penetration by a SO₂-calcium bisulfite brine was determined. The structural features of the cuticle are interpreted in the light of its possible significant to cuticular penetration. The morphology of the cuticle was determined by standard histological and histochemical techniques. The surface structure of the cuticle was studied with a scanning electron microscope. Enzymatically isolated cuticles were used to evaluate the effect of the cuticle on the penetration of the various components of brine. The surface of the cuticle was found to have a smooth to granular sheet or layer of surface wax which when removed revealed a porous sponge-like surface. The surface wax was found to be intermittently birefringent which increased as the fruit matured. Ectodesmata (MP) were found to occur over anticlinal walls and in guard cells on both sides of the fruit with more on the side opposite the suture. Both sides, were stomatous with more occurring on the suture side. Secondary bleaching was found to alter the structure and permeability of the cuticle. Removing the wax was found to increase percent weight loss as well as increasing cuticular penetration. Ion penetration was found to be generally greater from the outside to the inside than the inside to the outside surface and was greater from the side opposite the suture than the suture side. Potassium from potassium bitartrate was found to penetrate rapidly while SO₂, Ca⁺⁺, and H⁺ were delayed. It was concluded from this study that calcium penetration entered by a different route than SO₂; the major penetrating species of SOp in water and brine would seem to be molecular SCX and bisulfite ion; stomatal pores were not the sites of entry; ectodesmata were probably the sites for polar entry; the guard cells were more important for potassium penetration while ectodesmata in astomatous regions were more important for SO₂ penetration; and one of the major factors involved in penetration of brine is the waxy layer on the cuticle. Causes, preventative measures and recommendations for the structural defect known as "solution pockets" are discussed in light of the structure and penetration data. / Graduation date: 1972

Graduation date: 1987

Graduation date: 1942

Graduation date: 1954

Thesis (Ph. D.)--University of Wisconsin--Madison, 1957. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 41-43).

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 56.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1960. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 104-108).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 113-115).