Bean leafroll virus

Bean leafroll virus (BLRV)

Profile

Bean leafroll disease is caused by bean leafroll virus (= pea leafroll virus). Affected plants are severely altered in appearance. The virus can cause yield losses of up to 50%.

Damage symptoms

The leaves are greenish-yellow in color and are conspicuously upward at an acute angle. They are cone-shaped rolled upwards and rigid. This greatly changes the appearance of the entire plant. The flowers may also fall off.

Host plants

In addition to field bean(Vicia faba), bean leafroll virus occurs on numerous other plant species in the legume family (Fabaceae), with symptoms of damage varying by plant species:

  • Alfalfa(Medicago sativa): plants usually show no symptoms.
  • pea(Pisum sativum): chlorotic, downward curled leaves
  • White clover(Trifolium repens): yellowish, curled leaves
  • Common bean(Phaseolus vulgaris): yellowish discolored leaves
  • Chickpea(Cicer arietinum): yellowish discolored leaves
  • cowpea(Vigna unguiculata): yellowish discolored leaves
  • Lentil(Lens culinaris): yellowish discolored leaves

Distribution

Bean leafroll virus is widespread worldwide.

Propagation and transmission

The virus is transmitted by several aphid species, with the pea aphid(Acyrthosiphon pisum) as the main vector. The viruses are transmitted persistently by the aphids, i.e. these are only taken up by the vectors after a longer sucking period, remain infectious in the insect body for a long time and can only be transmitted to healthy plants after a certain period of time. These viruses are mechanically difficult or impossible to transmit. From overwintering legumes, mainly red clover, white clover and alfalfa, aphids can also transmit the virus to distant field bean stands.

Economic importance

On field beans, leafroll disease can totally alter the growth habit of the plants. Early infections can cause yield losses of up to 50%.

Prevention and control

Last updated: 17.11.2021

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