A few of my broad beans have died off. They got to about 4" or 5" high, then brown streaks appeared on the leaves, after a while they went all brown and died off. Never seen this before, any ideas ?
Sounds like chocolate spot to me.
Treatment: Remove and destroy diseased plants and spray the rest with carbendazim.
Prevention: Apply Growmore fertiliser before sowing, and don't grow them too close together (Thanks to DG Hessayon)