Issue link: http://read.dmtmag.com/i/34759
Members of the breeding program’s Industry Advisory Council visit a Phase 3 evaluation site at Quincy in 2010. They are: (from left) Dave Gleason, Kershaw Companies; Harold Schell, Washington Tree Fruit Research Commission member and field services manager at Chelan Fruit Cooperative; Jeff LaPorte, Chelan Fruit; and Tim Welsh, Columbia Fruit Packers Inc. Table 1: Ranking of traits in new varieties Rank Trait 3.86 Flavor out of storage 3.57 Crisp 3.53 Precocity (normal) 3.5 Low russet potential 3.47 Juicy vs. woody (dry) 3.43 Firmness retention 3.33 Acidity greater than Golden Delicious 3.33 Yield equal to commercial standard 3.2 Not bitter pit prone 3.19 Size between 100 and 48 3 Not prone to scald 3 Not prone to sunburn 2.93 Skin color coverage greater than 20% 2.73 Powdery mildew resistant 2.66 Fireblight resistant 2.56 Tender skin 2.56 Compact growth habit 2.53 Brix above 15° 2.5 Not prone to watercore 2.19 Yellow ground color rather than green 1.7 Red color vs. no red color Members of WSU’s Genetics, Genomics and Breeding Team and the breeding program’s Industry Advisory Council ranked these traits on a scale of 1 to 4, with 4 being critical in a new variety and 1 signifying not important. storage and crispness were the top two. Six of the top ten traits are related to appearance, packout, or yield, which would be considered commercial traits rather than consumer traits. The intended use of this ranking is to prioritize genetic targets for the GGB team. Phase 3 In Phase 3 trials, further phenotyp- ing—the observation of properties of a genotype (variety) that are produced by the interaction of the genotype and the environment—is undertaken under the www.goodfruit.com leadership of Tom Auvil and Dr. Ines Hanrahan (both with the Washington Tree Fruit Research Commission’s internal program). There are four Phase 3 sites, with environmental differences driven mostly by elevation. The aims of Phase 3 trials are fourfold: • Provide adequate volumes of fruit from different environments to determine storage and postharvest handling behavior • Observe the interaction of a genotype and the various environments in which it is grown. • Allow growers to visit trial sites to see the trees and fruit in production prior to engaging in evaluation agreements • Provide fruit for nursery trade show booths and gift box volumes for marketing organizations The Industry Advisory Council meets annually in November to review results from the growing season. The most commonly shared trait of the ten selections currently in the Phase 3 plantings is crisp texture. Most genotypes do not have sunburn damage. A couple of genotypes have some bitter pit, but far less than Honeycrisp. Mildew has not been an issue with any of the genotypes, though it can be found if sought out. The greatest challenge has been stem end splitting, which has been seen in several genotypes at or just prior to commercial harvest maturity. Two selections have compact growth habit, two are vigorous, the rest are intermediate. Two have high crop densities (will overcrop), and two are not precocious, leaving six intermediate. Fruit size ranges from moderate to very large, which means bigger than Gala for moderate and equal to Honeycrisp for very large. All of the Phase 3 genotypes have responded well to 1-MCP. A few do not have the storage life needed for a commercial variety, and their evaluation will likely be discontinued. Of the ten selections, two (WA 2 and WA 5) have been released into Phase 4 grower evalua- tion, with WA 2 already moved into Phase 5 commercialization. At least one and possibly more releases are expected from this batch of Phase 3 genotypes. New material has been propagated for Phase 3 plantings in 2012. • GOOD FRUIT GROWER JULY 2011 31 WASHINGTON STATE UNIVERSITY