Northwest berry Foundation

Management Detail

Bacterial Blight/Bacterial Canker

in Blueberries

Click here if you would like to select another pest.

 

Latin name: Pseudomonas syringae pv. Syringae

Description:

Reason for Concern:
1) Severely infected canes and flower buds that may be killed before they can open reducing yields.
2) Young plants may be killed if lesions are extensive.
3) Atlantic, Burlington, Coville, Chandler, Darrow, N15G (Eberhardt), and Patriot are very susceptible; Elliot, Rancocas, and Weymouth seem more resistant.

Identification/Symptoms:
Symptoms first appear in January or early February as water-soaking on 1-year-old stems. The lesions rapidly develop into reddish brown to black, irregularly shaped cankers with definite margins. Cankers can extend from a fraction of an inch to the entire length of the stem or girdle stems. Buds in or above the canker area are killed. If the stem is not girdled, buds above the canker grow. Leaves turn orange and wilt if death occurs after buds have leafed out. Severe Botrytis infection can cause similar symptoms.

Disease Cycle:
The bacterium survives and multiplies on the buds, bark and stem surfaces but causes no damage until it enters the stem. Entry is through wounds, natural openings such as leaf scars, and probably through frost- or winter-injured tissues as well. It spreads by wind, rain, insects, propagation wood, and pruning tools. Cold weather and moisture favor the disease.

Links:

Scouting:

  • Water-soaked lesions appear on canes in January or early February and rapidly becomes reddish brown to black canker.
  • Cankers may extend from a fraction of an inch to the entire length of the 1-year-old cane.
  • Buds in cankers die. If the stem is not girdled, buds above the canker grow.
  • If girdled, the cane portion above the canker dies.
  • Leaves turn orange and wilt if death occurs after buds have leafed out.
  • Only canes produced the previous season are attacked.

 
Cultural Controls:

  • Scout for the disease and prune out diseased wood as soon as it is noticed.
  • Avoid over-fertilization and late-season fertilization.

 

For information about chemical controls, check with our Pesticide Guide.

images


photo by T. Peerbolt


photo by T. Peerbolt


photographer unknown


Photo by T. Peerbolt


photo by P. Bristow

 

WebSite Sponsors

This site provides practical and objective information in support of the berry industry. It is maintained by the Northwest Berry Foundation and funded entirely through the donations of our generous sponsors.

Please click on their logos and find out more about them.

 

Northwest Berry Foundation

Northwest Berry Foundation

© 2016

Get in touch

5261 North Princeton Street

Portland, OR 97203

Office: 503-285-0908

FAX: 503-289-7488


Email us