Fruit & Vegetable Magazine

Features Fruit Production
Examining berry-splitting in blueberries


May 30, 2011
By Sharon Durham USDA-ARS

Topics

bbsplittingMay 26, 2011– U.S. Department of Agriculture
(USDA) researchers and a university colleague have found several factors
involved in blueberry splitting, a significant problem that can cause losses of
$300 to $500 per acre.

May 26, 2011– U.S. Department of Agriculture
(USDA)
researchers and a university colleague have found several factors
involved in blueberry splitting, a significant problem that can cause losses of
$300 to $500 per acre.

Splitting and cracking
occur in southern highbush and rabbiteye blueberries if they receive preharvest
rainfall when fully ripe or approaching ripeness, according to scientists with
USDA’s Agricultural Research Service
(ARS)
. ARS is USDA’s principal intramural scientific research agency.

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bbsplitting 
ARS horticulturist Donna
Marshall and her colleagues are solving the problem of splitting in blueberries,
which can cause expensive losses for growers.
 

ARS horticulturist Donna
Marshall, retired horticulturist James Spiers and geneticist Stephen
Stringer at the ARS Thad Cochran
Southern Horticultural Laboratory
in Poplarville, Miss., and University of Southern Mississippi associate
professor Kenneth Curry collaborated on the research studies published in HortScience.

In the first study,
published in 2007, the researchers developed a laboratory method to model
rain-related splitting in blueberries. Many blueberry breeders throughout the
country are using this method to more vigorously screen cultivars and
selections for splitting susceptibility. The results from field and laboratory
tests showed that the rabbit-eye cultivar Premier has the lowest incidence of
splitting, while widely grown cultivar Tifblue exhibited a high incidence of
splitting.

Marshall and her
colleagues also investigated the correlation between splitting susceptibility
and fruit firmness. Laboratory and field tests proved that, in general, firmer
fruit has a higher tendency to split. But one selection, named MS614, exhibited
extreme firmness and splitting resistance. The results, published in 2008,
suggest that breeders who select for firmness may inadvertently also be
selecting for splitting. But the laboratory screening method Marshall and
colleagues created has helped remedy this problem.

The most recent study,
published in 2009, evaluated water-uptake thresholds in split-resistant Premier
and split-susceptible Tifblue fruit at all stages of development. The
researchers harvested and weighed the fruit, then soaked it in distilled water
at room temperature for 24 hours. They found that Premier absorbs more water
than Tifblue, yet remains intact and experiences minimal splitting. According
to Marshall, the studies show that splitting is a cultivar-specific problem.

Read more
about this and other blueberry research in the May/June 2011 issue of
Agricultural Research magazine.