Fava disease

[Gio]

I have a question about the fava beans in my garden. About 10% of the plants are developing a...thing. It causes the new growth to wilt and top leaves to shrivel and turn black, and the flat parts of the stems become black (this is pronounced and I think will be the determining symptom). I don't think it is fusarium wilt given the black stem margins. I'm attaching a few pics. Chocolate spot? I'm seeing leaf pictures of chocolate spot, but never stem photos like mine.

Any idea?

I don't see any aphids. Most of the plants look perfect and very vigorous and flowery. I planted these from dry fava beans I bought for eating.

Whatcha think?

I have never planted favas in this particular place before (although not far away last year), and the plants that become sick are kind of randomly distributed around the patch.

Thanks!

[imafan26]

This looks like chocolate spot, caused by botritis. Usually, the plants should be pulled to keep the spores from spreading.

https://goldengategarden.typepad.com/go ... fraid.html
https://saskpulse.com/resources/chocola ... aba-beans/

[applestar]

Ah ha! I don’t grow fava beans often but had something like this infection on them one year. I didn’t know what it was though.

Since they looked obviously sick, I ended up pulling them up as the tips and potential flowering buds wilted.

The ones that survived were then demolished by subsequent mass infestation by black aphids.

Hope there’s a way to get them through this and strengthen their health so they would be less vulnerable to any pests. Good luck.