Title page for ETD etd-04262000-13090002

Type of Document Master's Thesis
Author Lewallen, Kara
URN etd-04262000-13090002
Title Effects of Light Availability and Canopy Position on Peach Fruit Quality
Degree Master of Science
Department Horticulture
Advisory Committee
Advisor Name Title
Marini, Richard P. Committee Chair
Barden, John A. Committee Member
Byers, Ross E. Committee Member
Parrish, David J. Committee Member
  • Firmness
  • Light
  • Peach
  • Prunus persica
  • Fruit Quality
  • Ground Color
Date of Defense 2000-04-10
Availability unrestricted
Two experiments were conducted to determine the influence of light on 'Norman' and 'Cresthaven' peach fruit quality characteristics. Of primary interest was the relationship between ground color and flesh firmness. Light levels were manipulated by use of shade cloth, reflective mulch, and aluminum foil. 'Norman' trees, with a randomly chosen half of the canopy covered with 73% shade cloth, had fruit with lower levels of red color, soluble solids concentration (SSC), specific leaf weight, and average photosynthetic photon flux (PPF) than did non-shaded trees. Foil-covered 'Cresthaven' fruit were larger, less firm, and had lower SSC than non-covered fruit. Covered fruit developed yellow but not red color.

Position of the fruit within the canopy of the tree also affected fruit quality characteristics. Inside fruit on both 'Norman' and 'Cresthaven' trees were smaller and firmer, had lower SSC, and were less red than fruit from the canopy exterior. The position effect was probably due to the degree of light exposure and not to the distance from the roots. Fruit on the inside of the tree canopies received much lower average PPF than outside fruit.

Relationships were evaluated between ground color and firmness for both cultivars. At a given hue angle, fruit developing in high-light environments were firmer than fruit from low-light environments for 'Cresthaven', but the opposite was true for 'Norman'. Therefore, canopy position or the light environment in the vicinity of the developing fruit does not consistently influence the relationship between hue angle on the non-blush side of the fruit, and flesh firmness.

  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  part1.pdf 84.76 Kb 00:00:23 00:00:12 00:00:10 00:00:05 < 00:00:01
  part2.pdf 18.88 Kb 00:00:05 00:00:02 00:00:02 00:00:01 < 00:00:01
  part3.pdf 197.82 Kb 00:00:54 00:00:28 00:00:24 00:00:12 00:00:01

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.