How to Manage Pests

UC Pest Management Guidelines

Dry Beans

Cucumber Mosaic

Pathogen: Cucumber mosaic cucumovirus (CMV)

(Reviewed 8/07, updated 8/07)

In this Guideline:


Symptoms of cucumber mosaic in common beans vary considerably and depend on the variety and strain of the virus. Severe symptoms may include dark green blisters and vein banding, interveinal yellowing and leaf distortion that may resemble damage due to the herbicide 2,4-D. Milder symptoms may include a light green to dark green mottle and some green vein banding, and can be confused with those caused by Bean yellow mosaic potyvirus and Bean common mosaic viruses.


Cucumber mosaic cucumovirus has a very wide host range and infects many crop, ornamental, and weed plants. However, only certain strains of Cucumber mosaic cucumovirus infect common beans, and these have been reported to also infect alfalfa, peas, pepper, lima bean, and blackeye. Cucumber mosaic cucumovirus can be seedborne in bean and is transmitted by aphids. It can also overwinter in perennial crops and weed hosts.


Because this disease is not very common, it does not warrant the use of control measures. The use of certified seed will help minimize the incidence of seedborne cucumber mosaic. As for Bean yellow mosaic virus, growers may want to avoid growing beans adjacent to alfalfa fields or, in the case of Cucumber mosaic cucumovirus, established pepper fields. There are no Cucumber mosaic cucumovirus resistant varieties, although some varieties are more tolerant than others.


[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Dry Beans
UC ANR Publication 3446


R. M. Davis, Plant Pathology, UC Davis
C. A. Frate, UC Cooperative Extension, Tulare County

Acknowledgment for contributions to Abiotic Disorders:
A. E. Hall, Botany and Plant Sciences, UC Riverside
Acknowledgment for contributions to Diseases/Abiotic Disorders:
S. R. Temple, Plant Sciences, UC Davis
Acknowledgment for contributions to Diseases (viruses):
R. L. Gilbertson, Plant Pathology, UC Davis

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