ALLEVIATION OF CHILLING INJURY, AND ITS MECHANISMS TO MARSH AND REDBLUSH GRAPEFRUIT (CITRUS PARADISI MACF.).

Persistent Link:
http://hdl.handle.net/10150/184769
Title:
ALLEVIATION OF CHILLING INJURY, AND ITS MECHANISMS TO MARSH AND REDBLUSH GRAPEFRUIT (CITRUS PARADISI MACF.).
Author:
ALJUBURI, HAMEED JASIM.
Issue Date:
1982
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The sensitivity of Arizona-grown grapefruit to chilling temperatures varied throughout the harvest period studied. This sensitivity was high in October, decreased in November and December, then increased in February. In April and May there was another decrease in sensitivity to chilling temperatures. Coating fruit with vegetable oils or fats successfully delayed the development of chilling injury and reduced the degree of injury, however, vegetable oils applied as water emulsions were even more effective in preventing chilling injury to 'Redblush' grapefruit extending the period of marketability more than 100 days. Postharvest application of CaCl₂ and certain plant growth regulators significantly increased the resistance of 'Marsh' grapefruit to chilling injury, but less so than oil emulsions. Scanning electron microscope photomicrographs of 'Marsh' grapefruit peels showed that severe chilling injury was a depressed area of collapsed cell, just beneath the epidermis layer. As the severity of chilling injury increased, non-collapsed cells gradually increased in size. Cell walls were irregularly shaped; thin in some areas and thick in others. Oil glands in depressed areas were not ruptured during cold storage. Hence release of toxic materials through rupturing of oil glands is not a factor in chilling injury. Compared to non-injured tissue, injured tissue from the same fruits had significantly lower water and osmotic potentials, and low, near zero, turgor pressures. There was a significant negative correlation (r = -0.5; p < 0.05) between the water potentials of the peels and the percentage of 'Marsh' grapefruit with severe chilling injury during storage at 2.8C. Ion leakage tended to increase during cold storage, and when the fruit were transferred to room temperature. Internal conductivities declined sharply during cold storage and then increased very strongly during periods at room temperature.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Grapefruit -- Climatic factors.; Grapefruit -- Arizona.; Plants -- Effect of cold on.; Plants -- Frost protection -- Arizona.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Plant Sciences; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleALLEVIATION OF CHILLING INJURY, AND ITS MECHANISMS TO MARSH AND REDBLUSH GRAPEFRUIT (CITRUS PARADISI MACF.).en_US
dc.creatorALJUBURI, HAMEED JASIM.en_US
dc.contributor.authorALJUBURI, HAMEED JASIM.en_US
dc.date.issued1982en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe sensitivity of Arizona-grown grapefruit to chilling temperatures varied throughout the harvest period studied. This sensitivity was high in October, decreased in November and December, then increased in February. In April and May there was another decrease in sensitivity to chilling temperatures. Coating fruit with vegetable oils or fats successfully delayed the development of chilling injury and reduced the degree of injury, however, vegetable oils applied as water emulsions were even more effective in preventing chilling injury to 'Redblush' grapefruit extending the period of marketability more than 100 days. Postharvest application of CaCl₂ and certain plant growth regulators significantly increased the resistance of 'Marsh' grapefruit to chilling injury, but less so than oil emulsions. Scanning electron microscope photomicrographs of 'Marsh' grapefruit peels showed that severe chilling injury was a depressed area of collapsed cell, just beneath the epidermis layer. As the severity of chilling injury increased, non-collapsed cells gradually increased in size. Cell walls were irregularly shaped; thin in some areas and thick in others. Oil glands in depressed areas were not ruptured during cold storage. Hence release of toxic materials through rupturing of oil glands is not a factor in chilling injury. Compared to non-injured tissue, injured tissue from the same fruits had significantly lower water and osmotic potentials, and low, near zero, turgor pressures. There was a significant negative correlation (r = -0.5; p < 0.05) between the water potentials of the peels and the percentage of 'Marsh' grapefruit with severe chilling injury during storage at 2.8C. Ion leakage tended to increase during cold storage, and when the fruit were transferred to room temperature. Internal conductivities declined sharply during cold storage and then increased very strongly during periods at room temperature.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectGrapefruit -- Climatic factors.en_US
dc.subjectGrapefruit -- Arizona.en_US
dc.subjectPlants -- Effect of cold on.en_US
dc.subjectPlants -- Frost protection -- Arizona.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePlant Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.committeememberBartels, Paul G.en_US
dc.contributor.committeememberOebker, Norman F.en_US
dc.contributor.committeememberBessey, Paulen_US
dc.contributor.committeememberFazio, Steveen_US
dc.identifier.proquest8303379en_US
dc.identifier.oclc683255908en_US
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