WSU releases second new apple, called WA 5
WSU’s apple breeding program envisions a portfolio of new and improved cultivars.
Just a year after the release of WA 2, WSU’s apple breeding program in Wenatchee is releasing its second new cultivar, WA 5. WA 5 is sufficiently different from WA 2 in ripening season, appearance, and eating quality to justify its release.
With a bright orange-red stripe covering 60 to 90 percent of the yellow background, it is certainly eye-catching. It is rarely marked by russet and has small and inconspicuous lenticels, unlike the larger lenticels of WA 2.
Fruit of WA 5 has excellent texture. It is firmer, crisper, and juicier than Gala and WA 2 (see “Fruit quality ratings” table) and maintains its texture in storage and on the shelf. Fruit is round and generally intermediate in size (smaller than Fuji and Braeburn but larger than Gala). WA 5 fruit ripens in early to mid-September, and its exceptional texture and eye-catching appearance particularly suit the fresh market.
WA 5 originated from a cross between Splendour and Co-op 15 (a selection from the Purdue/Rutgers/Illinois apple scab resistance program) made in 1994 by Shawn Mehlenbacher at Oregon State University on behalf of the WSU breeding program. The seed was transferred to WSU later that year. The seedling tree was selected for its excellent fruit quality and appearance in 2001 and propagated for Phase 2 trials, which were planted at three sites in central Washington in 2004. Four commercial orchard Phase 3 trials with larger tree numbers were planted in 2007 in central Washington on Malling 9 rootstock.
In the Fruit Quality Comparisons table, the quality of WA 5 is compared with WA 2, Gala, Fuji, Braeburn, and Cripps Pink. Firmness is similar to Braeburn, higher than Gala and Fuji, and lower than Cripps Pink. Sugar levels are comparable to Braeburn and lower than Gala, Fuji, and Cripps Pink. Acidity levels are intermediate—higher than Gala and Fuji and lower than Braeburn and Cripps Pink. WA 5 is firmer than WA 2, which is harvested later, but has generally lower sugar levels and similar or higher acidity. All data shown are from 2009, but similar observations have been made each season since 2006.
|Fruit quality comparisons|
|Fruit quality in 2009 for WA 5, WA 2, and four reference cultivars for fruit at harvest (fresh) and after 60 days in regular air cold storage from two locations in central Washington.|
(% soluble solids)
(mg/L malic acid)
|Mean fruit |
|Cultivar||Location A – near Lake Chelan, high elevation|
|Location B – just north of Richland|
WA 5 productivity, as estimated from Phase 2 trials, falls within the range of existing commercial cultivars. It is precocious, with significant crops in year two, and forms a tree of intermediate growth habit (not spur-type or tip-bearing), similar in tree size to Braeburn, and weaker than Gala and Fuji. Comparisons of yield efficiency (when yield per tree is adjusted to a similar tree size) show that productivity of WA 5 is intermediate, falling below Braeburn but similar to Gala and Fuji. It shows only moderate susceptibility to powdery mildew and fireblight. Laboratory DNA tests have shown that it has the potential to be resistant to apple scab (a trait from its parent Co-op 15), but it has not been tested in growing conditions with high scab pressure.
|Fruit quality ratings|
|Mean subjective ratings of fruit quality (hardness, crispness, and juiciness) for WA 5 and two comparison cultivars based on data from several harvest dates in 2009 from fresh and stored fruit from two locations in Washington.|
Values are subjective ratings on a 1 to 5 scale with 1 extremely poor, 2 poor, 3 average, 4 very good, and 5 outstanding.
There are two essentials in the growing of WA 5 to obtain the highest fruit quality possible. It is necessary to adequately thin the crop and to not pick the fruit too early. Overcropping and early picking can significantly reduce eating quality by reducing sweetness and juiciness.
Trees will be available for Washington grower evaluation plantings (Phase 4) in spring 2011, following the same release protocol established for WA 2 by the master licensee (Washington Tree Fruit Research Commission) and outlined in the October 2009 issue of the Good Fruit Grower. Evaluation agreements will be available for five-tree trials in spring 2011. Only growers who have evaluation agreements will be able to establish commercial plantings (Phase 5) in the future. Fruit will be available for tasting at the Washington State Horticultural Association Show in December in Yakima.
The release of this second variety, WA 5, supports the WSU apple-breeding program’s vision of a portfolio of new and improved cultivars. Its outstanding crispness and juiciness, appearance in the box, and relatively early season (just after Gala) make it a variety with considerable commercial potential.