Photo by Scott Bauer.
Blackberries, with their luscious sweetness balanced with enough acid to ensure mouth-watering flavor, are increasingly whetting consumer appetites. Their inherent goodness, augmented by their high level of healthful antioxidants and their greater availability in markets, will likely accelerate their popularity.
New cultivators, plus innovative techniques that manipulate the canes for more advantageous fruiting times and mitigate the pains of winter damage, should increase demand still more. More regions can now profitably grow and market blackberries.
The Rotating Cross-Arm trellis and cane training method developed by Dr. Fumiomi Takeda, lead scientist at USDA's Appalachian Fruit Research Station in Kearneysville, ., allows the blackberry canopy to lie close to the ground. Then, row covers on the canopy moderate the temperature to prevent winter injury. Trials in West Virginia with Black Diamond and Siskiyou varieties showed production of over 12 pounds per plant after the winter temperature dipped below 0 degrees Fahrenheit. Takeda says that system can grow erect-type blackberries in USDA winter hardiness zones 4 and 5.
The breeding program at the University of Arkansas, headed by Dr. John R. Clark, developed the Prime-Ark Primocane-Fruiting Blackberry Series. This breakthrough with primocanes that produce berries the first year enables more northern areas to grow blackberries. Areas with cold winters traditionally have not allowed the overwintering of the canes. With these cultivars, blackberries can be produced if the season is long enough to produce fruit. With primocane fruiting the canes can be mowed each winter, and the plant will produce a fall crop in areas such as New York state on the new canes which fruit. These varieties are thorny and erect in habit. All in the series are patented.
Prime-Jim produces small, 1.9-gram berries with a sugar content of 13.1 percent. The flavor is good, and the berries have moderate firmness. High summer heat can lower yields more than Prime-Jan.
Prime-Jan, at 3.1 grams, is also flavorful with moderate firmness and small seeds. It produces fruit on one-year wood in late August and September, and is earlier and more productive than Prime-Jim.
Prime-Ark 45 produces firm fruit that can be shipped. Also, the fruit retains its black color and is not prone to mold or leakiness, thus it stores well. At 6 grams in Arkansas, it can produce larger fruit in cooler areas. Plus, Prime-Ark yields better than the previous two in the series.
The North Carolina State University team of Dr. James R. Ballington, Dr. Gina E. Fernandez and Dr. Penny Perkins-Veazie developed NC 430, a fresh market floricane-fruiting blackberry.
NC 430 has demonstrated high yields. What's more, this blackberry produces late in the season. With an average fruit weight of 6.6 grams, its sweet flavor, small seeds and low acidity make NC 430 distinctive. Over a three-year period, it produced an average of 21,434 pounds per acre, higher than any of the other cultivars tested. In post-harvest evaluations for mold, leakiness, softness and red drupe of blackberries held seven days at 39.2 degrees Fahrenheit and 90 percent relative humidity in clamshells, it did as well or better than the other varieties. Fernandez reports that NC 430 suits both the commercial and homeowner fresh market.
A research geneticist for USDA's Agricultural Research Service in Corvallis, Ore., Dr. Chad Finn's program has released several new floricane fruiting blackberry cultivars to nurseries.
Developed for either fresh roadside market or processing uses, Newberry is thorny and vigorous. It produces very high yields of large fruit. With the color and look of Boysen, but not the same flavor, it is sold in the California wholesale market as Ruby Boysen. However, Newberry holds its freshness better than Boysen with less bleeding. It can be machine harvested, and it processes well.
Onyx produces one week later than Marion and has similar yields. Onyx has medium-large fruit with uniform shape. The excellent flavor is sweet and fruity. With firm fruit and tough, glossy skin, it has shipped well in the wholesale fresh markets. In trials in 2006, Finn reports it came through a late freeze with no damage. The vigorous, thorny plant has long laterals. Onyx will be patented.
Among the thornless processing blackberries in the Oregon breeding program, Black Diamond is relatively new. This productive cultivar can be machine harvested. Larger and much firmer than Marion, it has goodflavor and fruit quality. It may have greater cold hardiness than Marion in regions such as the Willamette Valley.
Wild Treasure, a cross of Waldo and the native Rubus ursinus, combines the best traits of both. Thornless and foliar disease-tolerant, it has the yield of Waldo with excellent flavor and the growth habit and fruit size of the wild blackberry. This processing blackberry can be machine harvested.
The breeding program in Oregon is trialing two fresh market blackberries, ORUS 19394 and ORUS 27111. The first yields 20 percent more than Marion, with larger, 6.4-gram fruit. Beautifully glossy in appearance, it is firm with excellent sweet flavor. The thorny plant was not damaged in 2006's late freeze. ORUS 2711-1 ripens its excellent yields in late July to early August. Thornless, it has a semierect habit. The large fruit of ORUS 2711-1 is roundish, glossy, firm and very sweet.
In the processing blackberry trials, thornless ORUS 2707-1 has shown outstanding yields. With excellent fresh and processed fruit quality, it may be harvested by machine.
In small grower trials, it is sensitive to hot temperatures. ORUS 3447-1 is also thornless and has outstanding yields. In its small-scale grower trials, it was termed the most exciting in its first year that the Oregon program has ever developed. Machine harvestable, ORUS 3447-1 has demonstrated excellent flavor plus fresh and processed fruit quality.
Finn's research includes cooperating with New Zealand breeder Dr. Harvey Hall. Two processing blackberry cultivars evaluated in Oregon are NZ 9629-1 and NZ 9671-1. Both are selections made in Oregon from crosses made in New Zealand. Thornless, NZ 9629-1 has a nice training habit. The medium-firm fruit is small to medium in size and very uniform in shape. With an excellent flavor, it has shown medium yields. NZ 9671-1 appears to be machine harvestable with good yields. A thornless Logan type, it has generated interest from growers.
Kathy Demchak, Penn State University; Dr. Andrew Jamieson, Agriculture and Agri-Food Canada in Nova Scotia; Dr. James Luby, University of Minnesota; Dr. Courtney Weber, Cornell University; and others collaborate with those mentioned in their variety development and trials.
Note: These cultivars, except some of those in trial, are available from nurseries such as Indiana Berry, Norcal, Nourse Farms and others.
The author is a writer-researcher specializing in agriculture. She currently resides in central Pennsylvania.