Tuesday, March 5, 2013

Mummy berry emerging this week

Mummy berry is now active in southeastern NC -- the photos below were taken yesterday.  The disease begins each spring with the emergence of the fungus from last year's infected fruit (mummies) that have overwintered on the ground.  The first sign of activity (and potential for infection) is the appearance of apothecia or "mummy cups" in spring.  Spores from these small brown cup-shaped mushrooms infect emerging blueberry shoots.  Yesterday at the NCSU Horticultural Crops Research Station in Castle Hayne, the spore-producing (infective) stage of this disease was visible on the ground underneath bushes in wet areas of some fields (click on images to enlarge):

Apothecium at right center of photo is less than an inch in height
Growth stage of bushes in the wet area where apothecia were found

Several mummy cups (apothecia) emerging from old infected berries

Mummies germinating through leaf litter 4 March 2013

The emergence of this fungus coincides with emergence of new shoots on blueberry bushes, so the disease will appear later in colder areas of the state where bushes are still dormant.  Fields in southeastern NC with a history of this disease should be sprayed with fungicides as soon as possible, especially in early-blooming cultivars where flower and leaf shoots are beginning to emerge. For further descriptions, and images of other stages of this disease, click here.  For specific recommendations on control, go to the NC Ag Chem Manual or the Southern Region IPM Guide.