HPIPM:Bacterial Vascular Necrosis Sugarbeets

Author: Howard F. Schwartz and David H. Gent

Identification and Life Cycle

Bacterial vascular necrosis, also known as Erwinia root rot, is caused by the bacterium Erwinia carotovora subsp. betavasculorum. The disease is generally confined to warmer sugarbeet growing areas, such as California, Arizona, Washington, Idaho, and Texas. Splashing water, insects, soil, and contaminated equipment may spread the pathogen. E. carotovora subsp. betavasculorum survives between sugarbeet crops in and on unharvested beets, soil, and weeds. Several races of the pathogen occur and can also attack tomato, potato, and chrysanthemum.

Plant Response and Damage

Foliar symptoms of bacterial vascular necrosis are not always apparent, but dark black streaks running up petioles can develop. Gas produced by the bacterium generate froth in the center of crowns. Root symptoms vary, ranging from soft rot to dry rot. Vascular bundles in roots become necrotic, and if cut and exposed to air turn pink to reddish. Wilt can result if roots become severely affected, but plants do not die from the disease. Roots can become hollowed-out cavities. Yield losses of up to 40% have been reported.

Biological Control

No biological control strategies have been developed for bacterial vascular necrosis.

Cultural Control

Plant resistant varieties where available. Avoid sprinkler irrigation, excess nitrogen fertilization, and low plant populations. Do not reuse irrigation tail water. Early planting when temperatures are cool can reduce losses, but may not be practical in some areas of the High Plains.

Chemical Control

No chemicals provide effective control of bacterial vascular necrosis.

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.