Broad Beans

[Rosyred]

I grew some more this summer are coming into bearing pods but I have either chocolate spots or rust on the leaves.
Question is can I just carry on growing as lots of flowers on them or do I have to say good bye??

[Rosyred]

[Kepouros]

Is it possible for you to decide which you have?

Broad Bean Rust starts with yellow marks on the upper sides of the foliage and the brownish marks appear later - usually surrounded with yellowish discolouration.  Chocolate Spot starts with brown marks.  Both are fungus diseases and there is no available treatment.

Rust can, but does not always, attack stems and pods as well as leaves, but as long as the weather remains dry the spots do not enlarge very quickly, and the attack can sometimes be slowed down by removing affected leaves immediately.

Chocolate spot is much more aggressive. It almost always spreads to attack the flowers and young pods (which it ruins) and can penetrate the older pods and discolour the beans.  There is nothing you can do to slow it down.

If you can decide which you have, you will at least know what to expect.  In either case don`t give up on them yet, but wait and see how they go on.  Pick any pods as soon as they are worth picking - if it is Rust you may well get quite a few and even with Chocolate Spot you have the chance of a few.

When the crop is finished take care to remove and destroy every scrap of of plant growth either by burning or by composting.

Although both diseases are fungal, the two conditions most likely to encourage their onset are close conditions (overcrowding or inadequate airflow) and an excess of nitrogen.  Don`t sow in heavily manured ground and don`t use compound fertilizers containing nitrogen, but simply feed with potassium and phosphorous fertilizers.

[Rosyred]

Thanks very much - i'll have a closer look at the plant this week.

[micsmum]

Mine always get loads of Blackfly!

[Multiveg]

According to The Archers, beans with chocolate spot are still edible. and were sold in the organic farm shop.

[Garjan]

@ micsmum:
My neighbour allotmenteer told me to pinch off the top of the plant as soon as it has small pods. This will encourage the beans to grow and the plant loses the part that is most attractive for black fly.

[micsmum]

Tried that Garjan and they were RIDDLED! :o

[Garjan]

Hi Micsmum
Sorry to hear that. It worked fine for me three years in a row now.
How much of the top did you take off? It has to be about 10-20 centimetres, my neighbour says.

[micsmum]

Oh! Probably too little - just sort of pinched them out Garjan. Then I sprayed them but only once.....and they were beasted! They were Witkiem Manita. Last year I planted The Sutton and they fared a little better so I might go back to them coupled with Bunyards Exhibition. Will take off much more top next year. Thanks for the advice.
Helen