Controlling viruses
Manage viruses by preventing their introduction. Virus develops from either infected seed or via aphids.
Seed-borne viruses of concern are Cucumber Mosaic Virus (CMV) and Alfalfa Mosaic Virus (AMV). Viruses brought in by aphids include Beet Western Yellows Virus (BWYV).
- Minimise the virus source (seed, Summer weeds or pasture).
- Sow virus free seed, <0.1% seed infection in high risk areas, <0.5% seed infection in low risk areas.
- Manage the crop to minimise aphid landing sites. Avoid bare soil – aphids land in crops where there is a clearly defined contrast in colour between bare soil and green foliage.
- Ensure good establishment
- Retain standing cereal stubble
- Produce a dense canopy
- Minimise herbicide "stress" as stressed plants that are more "attractive" to aphids.
- Control in-crop weeds early.
- Choose an aphicide that is "soft" on beneficials.
- Monitor for aphid activity and early control to minimise possible virus spread.
- Control any Summer legume and weed "green bridge" and any aphid build-up on them.
Cucumber Mosaic Virus (CMV).
Beet Western Yellows Virus (BWYV).
W Hawthorne, Pulse Australia; W Hawthorne, Pulse Australia