I never have much luck when it comes to any form of bean growing in my vegetable garden. The fungal diseases such as rust seem to get them every time. So my poor Broad Bean crop has copped the latest rust fungal infection.
What causes fungal rust?
A combination of factors. It can be due to slackness in proper crop rotation, an over heavy feeding of manure (high nitrogen levels) into the soil prior to planting, and planting of plants too close together so that the air flow is restricted.
What should be done to prevent rust?
Ideally, crops that you expect may suffer from rust should be planted where they get good morning sun with good air flow. Water the crop in the morning rather than in the evening. Check your soil's drainage as overly damp soil can encourage fungal issues.
It is better to feed broad beans potash as it hardens the plant and makes them less susceptible to disease. Try combining with a seaweed solution.
Rust can be difficult to treat as it can go into a dormant stage. Often omitting crops that are susceptible for around 2-3 years to help control the problem.
Yates Fungus Fighter or Leaf Curl Copper Spray are often recommended for fungal infections, however, they are only effective if you catch the very first sign of the fungus.
Chemically treating infected plants is not an effective method to contain the disease.
Using any form of a copper sulfate spray is actually not recommended for food crops as the chemical actually is absorbed by the fruit, so the plant that is sprayed should in fact not be consumed from for up to the next 18 months! Apricot tree owners, be warned.
Removing the diseased plants
If you catch the first signs of rust on your plants, simply remove the infected leaf matter immediately, placing them into a plastic bag and placing it into the general rubbish - never the compost or greens recycling.
When removing all the plants, they must be disposed of in a garbage bag and placed likewise into general rubbish also, to contain the outbreak. Remember to dig out the roots, too.
Can we eat the Broad Beans?
Some will eat their broad beans, some won't. It's up to the individual.
If the pods show signs of a fungus, do not consume.
Or if the crop is heavily affected, then it's time to be brave and pull them out entirely without a harvest.