Sunburn Reduction Using Surround WP

1. Sunburn Reduction Using Surround WP Ron Britt Private Consultant Yakima WA

2. Sunburn Reduction Using Surround WP • The purpose of this trial was to evaluate the efficacy of Surround WP, Raynox and Eclipse on apples for sunburn reduction and quality enhancement. • Granger WA • 6-year old Granny Smith on M9 rootstock and irrigated with a drip irrigation system, trained on a trellis system. • Trees were ca. 8 feet in height and planted on a 11.5 foot row spacing with 6 feet between the trees, ca.631 trees per acre. • The orchard floor has a permanent grass cover crop. • Conventional agronomic and pest management practices were followed.

3. Sunburn Reduction Using Surround WP • Five applications • Rears airblast sprayer • 1.5 mph; 115 psi • 100 gallons per acre (except 1st Surround application that was applied at 200 gpa)

4. Sunburn Reduction Using Surround WP Treatment List • Untreated Check • Surround WP at 50 lb/A followed by Surround WP at 25 lb/A • Raynox at 2.5 gallons/acre • Eclipse at 3 gallons/acre

5. Sunburn Reduction Using Surround WP Application Dates: June 27 July 8 August 10 August 28 September 12 All treatments applied to maintain coverage of fruit and foliage per commercial practices.

6. Sunburn Reduction Using Surround WP Evaluation: • Apples were sampled on 30 September 2008 at regular harvest time. • Professional apple pickers harvested one bin, approximately 22, 40 lb boxes of Granny Smith apples per plot. • Pickers harvested all of the fruit from each of the randomly selected trees from the middle of each plot. • Approximately 20 trees were picked per treatment to fill each bin with apples. • The fruit was transported immediately to cold storage. • On 30 October 2008 (one month after harvest), the sampled fruit was taken out of cold storage and processed over a Greffa electronic sorting line. • The electronic cameras separated the sunburned fruit from each sample. • The sunburned fruit for each sample was counted and the percent of sunburn damage was calculated.

7. Sunburn Reduction Using Surround WP a c b b

8. Sunburn Reduction Using Surround WP Results • The results for the sunburn evaluation indicated that all treatments performed better than the untreated control. • Eclipse, had the most sunburn damage of all the treated plots. • Raynox, had the second highest damage from sunburn in the treated plots and was statistically equal to the results in the Eclipse plot. • Surround WP, had statistically less sunburn damage than the other treatments. • Only 13.5 percent of the fruit treated with Surround WP was damaged from sunburn compared to Eclipse which had twice as much damage with 27.7 percent sunburn. • The untreated check plot had three times the sunburn damage as the Surround WP treatment.

9. Sunburn Reduction Using Surround WP [Surround cost is 50 lb/A + 25 lb/A applied 4 times; $39.50 + $79.00]

10. Sunburn Reduction Using Surround WPReturn on Investment

11. Sunburn Reduction Using Surround WP Conclusion • Surround WP was superior to the other sunburn control materials when applied multiple times throughout the summer to harvest. • Surround at $118.50/A was the most cost effective treatment compared to Raynox at $219.15/A or Eclipse at $300/A. • More applications on a shortening interval between applications may have reduced sunburn even more with the Surround WP