Disease risk and control
Risk factors for infection of a crop with rust are:
- sowing seed contaminated with infected seed
- spores produced on infected stubble from previous faba bean crops
- spores produced on volunteer bean plants in the previous year's faba bean stubble.
It is important to isolate new crops from last years faba bean stubble by at least 500 metres.
Spores produced on volunteer plants can be carried long distances by wind and will enhance the spread of the disease. Volunteers should be controlled early in the season. Where faba bean is followed by a canola crop, growers will need to use a herbicide which will kill the faba bean plants, rather than just retarding them.
Use clean seed
In areas where rust has occurred, do not use seed from paddocks in which rust was found. Sowing contaminated seed could be a method of spreading rust to new parts of Western Australia.
Know the resistance rating of your variety
Ascot, Farah, Fiesta and Fiord are all susceptible to rust. Ascochyta resistant varieties (Ascot and Farah) that are grown without routine ascochyta blight fungicide sprays are at increased risk of developing faba bean rust in favourable seasons. The ascochyta resistant variety Nura has improved resistance to rust (moderately susceptible) and has a lower risk of developing rust when grown without routine ascochyta blight fungicide sparys.
Several fungicides are registered for use against rust but they need to be applied before severe symptoms are seen. For crops with a yield potential greater than 1.5 tonnes per hectare spraying is necessary when the leaf area affected by rust exceeds 5% before the end of flowering.
Note: recommendations were current at the time this page was prepared.