Symptoms

• Mosaic viruses in which the leaves show sharply defined patches of unusual coloration may occur in beans.
• The causal agents of these symptoms may be nutrient imbalance or herbicide injury or result from infection by one of several viruses. Southern peas can be infected by Cowpea aphid-borne mosaic virus,Bean common mosaic virus and several others.
• It is not possible to distinguish between the viruses based on symptoms alone.
• Laboratory tests (ELISA) are required to identify the viruses and confirm that they may be responsible for the mosaic symptoms.

Management

• There are no recommended chemical controls for these problems.
• Many of these viruses are transmitted by aphids and are also transmitted through seed. For this reason it is unwise to save seeds from year to year.