New Jersey Ag News
Attendees updated on varieties of blueberries
By DOROTHY NOBLE
HERSHEY, Pa. — “Varieties make a difference,” USDA geneticist Dr. Mark Ehlenfeldt told a packed room of growers at the Mid-Atlantic Fruit and Vegetable Convention on Feb. 2.
Noting the recently released USDA plant hardiness zone charts, the Agricultural Research Services scientist said the warming trend can impact blueberry production.
The warm periods associated with climate change can spur early blossoming, only to be injured by subsequent frost. Cold hardiness becomes more important.
He reviewed standard and relatively new blueberry varieties, focusing on attributes such as fruit quality, harvest date, plant characteristics, disease resistance and adaptability.
Some of the newer cultivars feature novel colors and flavors and include more resistance, especially to anthracnose.
Varieties which can be harvested mechanically are becoming more prevalent and preferred due to today’s labor concerns.
Starting with the earliest producing varieties, Dr. Ehlenfeldt briefly described over a dozen cultivars of this popular fruit.
Hannah’s Choice has superior firmness, sweetness and flavor with peachy overtones. It produces large, first-pick berries with some decrease in size with later harvests. With average resistance to both phases of mummy berry, it is relatively resistant to anthracnose. In some areas it produces less, but does well in New Jersey.
In the early-season slot, Draper ripens with Duke but has a superior flavor. This 2004 berry from Michigan State’s breeding program is relatively susceptible to mummy berry blight.
But Draper is expected to be acceptable for machine harvesting.
The No. 1 blueberry in New Jersey, productive Duke bears medium-sized, firm fruit with a small dry scar on a vigorous upright bush. Since it blooms late, it avoids early frost, yet ripens relatively early. The mild flavor reportedly improves in storage.
The numerous canes are stocky and moderately branched. Duke’s buds and wood tolerate fluctuating winter temperatures well. Dr. Ehlenfeldt says the harvest can be completed in two or three pickings. Moderately resistant to anthracnose, it has resistance to mummy blight’s primary shoot infection, but has moderate susceptibility to mummy berry fruit.
Stem blight problems also have been documented. Reka exhibits an upright vigorous habit that has been productive in a wide range of soil types. Pennsylvania trials indicate potential for high yields. The small berries have a spicy flavor. This New Zealand cultivar has average resistance to anthracnose, and has relative resistance to both phases of mummy berry.
A new productive variety with excellent flavor, Sweetheart holds well in storage. It is not as precocious as Duke.
Dr. Ehlenfeldt advises cross pollinating and pruning, but not too heavily, to maintain fruit size. It reflowers in fall, but does not produce two crops. Sweetheart dislikes wet soil.
Turning to midseason varieties, Bluecrop shows consistent high production and good winter hardiness.
The season tends to be prolonged, which requires several harvests. Canes tend to be slender and whippy, which may make mechanical harvesting difficult. The numerous crack-resistant fruit is firm, flavorful and with small scars. Sometimes red backs occur.
Bluecrop resists shoestring and red ringspot virus, moderately resists mummy berry and powdery mildew, but is susceptible to anthracnose.
Released as a specialty cultivar for its exceptional fruit quality, Cara’s Choice produces firm, sweet, medium-sized, flavorful fruit.
Regarding its aromatic flavor with balanced brix and acidity, Dr. Ehlenfeldt said, “If you told me I had only one to eat in blueberry season, this is the one I’d eat.”
Cara’s Choice is earlier than Bluecrop but with only half its yields. Moderately susceptible to anthracnose, it resists mummy blight, and shows average resistance to mummy fruit infection.
Legacy, with its Southern background and tendency to hold its leaves through much of the winter makes its hardiness suspect. But its long harvest season leads to outstanding yields.
Its large, sweet, flavorful sub-acid fruit hold well. Also, Legacy produces juicy fruit—a trait many blueberry varieties lack. It resists anthracnose, and shows average resistance to both phases of mummy berry.
In mid to late season varieties, Ozarkblue flowers very late. Although yields are variable, the Bluecrop-like fruit stores well. It has average resistance to anthracnose and both phases of mummy berry.
Late season varieties include Aurora, released in 2004 from Michigan State from a cross of Brigitta Blue and Elliott. The huge, round berries have excellent taste, but need to hang for the best flavor development. It yielded very well in Oregon. It likely resists anthracnose and both phases of mummy berry due to its parentage.
Elliott fruits late in New Jersey. The vigorous bush plants are productive, and the late flowering avoids frost. The small berries are light blue with firm flesh. With this cultivar, unripe berries can be fully blue but still tart, so Dr. Ehlenfeldt suggests allowing them to remain on the bush before harvesting. Interplanting with another late variety that provides cross pollination improves both size and tastiness. Elliott stores well and measures high in antioxidants.
Liberty, also from Michigan State, ripens at the same time as Elliott but has better flavor. It yielded well in Michigan and Oregon but not in Pennsylvania, where it is producing more foliage than fruit. The quality and exceptional blue coloration of this flattish berry rank it favorably.
Based on its parentage, Liberty should resist anthracnose and mummy berry. In specialty cultivars, new pink varieties provide ornamental appeal as well as tasty fruit. Pink Champagne ripens second-early in New Jersey, mid-season in Michigan.
The dark pink fruit has good flavor, scar and firmness.
Its production varies in New Jersey, which researchers attribute to its southern germplasm that can result in sporadic flower bud hardiness problems.
The plants of Pink Lemonade are hardy in new Jersey, but fruit production is irregular.
In Oregon, mid to late season ripening resulted in moderate yields of medium-sized, glossy bright pink fruit with a mild, pleasant flavor and good firmness. Researchers suggest another variety to ensure good cross pollination.
Razz, a sibling of Bluecrop and Blueray, has reliable productivity with about 75 percent of Bluecrop’s yields in mid-season.
Its medium to large fruit with medium to light blue coloration has an excellent flavor with raspberry overtones.