Avoiding the Mummy's Curse

By Susan Littlefield, September 9, 2010

Blueberries are a popular fruit for home gardeners. They are generally easy to grow and the berries are delicious and highly nutritious. But sometimes the mature berries shrivel up, turning gray and hard. Blossoms turn brown and dry up, immature berries may fall before they ripen and eventually the tips of branches may wilt and die.

The cause of all these symptoms is a fungal disease called mummy berry. It occurs sporadically, usually after a cool, wet spring. It's a difficult disease to control because once you see the mummified berries, it's too late to do anything other than clean up and destroy all the infected berries to minimize the amount of fungus that overwinters.

So it's helpful to know which varieties of blueberries show the most resistance to this disease. Researchers at the USDA Agricultural Research Service recently estimated the relative resistance of different blueberry varieties by quantifying the average annual percentage of blighted shoots and mummified berries on a large number of cultivars.

Among the ones with the fewest mummified berries (less than 3%) were 'Brunswick', 'Chignecto', 'Fundy', 'Putte' and 'Zuckertraube' low bush blueberries, 'Chippewa', 'North Country,' 'Northsky' and 'St. Cloud' half highs (cross between low and high bush), and 'Pearl River', a cross between a southern highbush and rabbiteye blueberry. The highbush cultivars that rated best (10.3% or less mummified berries) were 'Bluegold', 'Bluejay', 'Brigitta Blue', 'Patriot', 'Reka', 'Reveille' and 'Weymouth'. The varieties with the lowest percentage of blighted shoots did not always track with the ones with the fewest mummified berries, but among the highbush cultivars, the authors noted that 'Bluejay' was reliably resistant to both types of damage.

For an abstract of this research, go to: HortScience.

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