Crown gall OF Chrysanthemum

Disease Information

Crown gall

Agrobacterium tumefaciens

Symptoms and damage

appearing as galls on roots and at the base or "crown" of woody plants. Crown galls are also formed on ornamental woody crops such as roses, Marguerite daisies, and Chrysanthemum spp. as well as on vines and canes such as grapevines  and raspberries. Marguerite daisies, chrysanthemums and grapevines can become infected systemically. Occasionally, galls have been observed on field crops such as cotton, sugar beets, tomatoes, beans  and alfalfa , but the disease does not impact such crops economically. Crown gall is caused by Agrobacterium tumefaciens, a Gram-negative, bacilliform bacterium that is normally associated with the roots of many different plants in the field. This bacterium can survive in the free-living state in many soils with good aeration such as sandy loams where crown gall diseased plants have grown. The bacterium can also survive on the surface of roots (rhizoplane) of many orchard weeds.

Management

Chemical control

 Eradication of crown gall using creosote-based compounds, copper-based solutions, and strong oxidants such as sodium hypochlorite are transiently effective. The chemical eradicant application procedure is labor intensive and therefore costly both monetarily and to the environment. The superficial treatments are ineffective against systemically infected plants. Generally, chemicals are rarely used for control of crown gall.

 



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