()
  • Filter by:
  • Filter by fungi
  • Filter by virus
  • Filter by mite
  • Filter by bacteria
  • Filter by insect
  • Filter by deficiency

Bean Common Mosaic Virus

Bean Common Mosaic Virus

BCMV

virus

In a Nutshell

    A light and dark green mosaic pattern appears on the leaf blades (green-on-green mosaic)Parts of the leaves become raised, puckered or distortedAt later stages, leaves start to curl downward or rollPlants infected during the early growth stages may be severely stunted

Hosts: %1$s

· Bean

Symptoms

Initially, trifoliate leaves become slightly lighter in color. Gradually, a light and dark green mosaic pattern appears on the leaf blades (green-on-green mosaic). Some veins or parts of them show sign of chlorosis (yellowing). As the disease progresses, parts of the leaves might become puckered, blistered or distorted. Curled down or rolled leaves are other late symptoms. Plants which were infected during the early growth stages may be severely stunted and unproductive, with fewer pods and fewer seeds per pod. In some susceptible varieties, the virus can cause the blackening of roots, a symptom that is only observed at temperatures above 30°C.

Trigger

The primary source of inoculum are infected seeds. The secondary transmission from plant to plant occurs via infected pollen, vectors pests (mostly aphids) or through mechanical injury to the plants during field work. Symptoms and effects on yield depend on plant variety, environmental conditions (temperature and humidity) and time of infection. Runner beans seem to be immune to the virus, while pole beans and bush beans are more vulnerable. Losses of up to 100% can be found in susceptible plants grown from seeds carrying the virus (seed-borne infection). Later infections by aphids are usually less severe. At temperatures above 30°C the symptoms worsen.

Biological Control

Direct treatment of the virus is not possible. Diluted mineral oils can reduce the transmission of the virus by aphids, but in high concentrations these oils might be toxic to the plants.

Chemical Control

Always consider an integrated approach with preventive measures together with possible biological treatments. Chemical treatment of viral infections is not possible. Chemical control of the aphid vector is often ineffective.

Preventive Measures

    Use healthy seeding material from certified sourcesPlant resilient varieties whenever possiblePlant densely to prevent aphids from entering the canopyPlant early to avoid aphid peak populationsRemove infected plants when first symptoms are observedCultivate beans far from other bean production sitesRotate crops with non-host plantsPlant companion crops to block the aphids