ANTIOXIDANT DEFENSE SYSTEMS FOR PROTECTION AGAINST SUNBURN OF APPLE

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ANTIOXIDANT DEFENSE SYSTEMS FOR PROTECTION
AGAINST SUNBURN OF APPLE

• Jim Johnson
• Deirdre Fahy
• Preston Andrews

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RESEARCH FOCUS
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PROJECT BUDGETS
1000

• Sunburn - 1.5 lower
• Splitting - 27 lower
• Overall - 7 lower for 8,000 savings from last
  budget year

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RESEARCH HIGHLIGHTS

• Ascorbic acid sprays reduced sunburn after Fuji
  color break
• Sprays increased antioxidant levels more after
  color break
• Shade covers EC increased antioxidant levels
  after color break
• Collected most complete temperature/ light
  exposure data set for analysis

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1997 OTHELLO SPRAYS
Total sunburn

• 4th-leaf Fuji
• Bi-weekly sprays, 3X mid-Aug to Sept
• 2 4 ascorbic acid SylGard 309 (2 oz/ 100
  gal)

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1998 VANTAGE SPRAYS
New sunburn

• 4th-leaf Fuji
• Weekly sprays (100 GPA) from 7/15
• Most effective - 8/17 to 9/9
• Overall sunburn
• Control - 26
• 3 AsA - 20
• 3 iso-AsA - 18

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FUJI SKIN ASCORBIC ACID
mg/g FW
1998
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FUJI SKIN GLUTATHIONE
mg/g FW
1998
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1999 OBJECTIVES

• 1. Limiting steps in antioxidant system
• 2. Relationship between antioxidants, color
  development ripening events
• 3. Timing, uptake utilization of sprays
• 4. Lab assay ? susceptibility treatment
  efficacy
• 5. Analyze temperature/light exposure data ?
  predictive stress index

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ACKNOWLEDGEMENTS

• Funding from
• WTFRC
• WSU
• Cooperators
• Auvil Fruit Company
• Dave Allan