Chocolate spot is a broadbean thing that typically happens at this time of year. Like rust is a celery thing, or black spot an apple thing – all crops have a thing they do when life’s not completely to their liking. And in my case it’s sprung forth in the wet, humid conditions created by the weather and my over crowded crop. My broadys are jam packed this year. Usually 20cm apart, this year they’re closer to 5. The over sow was an insurance moment, unsure as I was of the older, unlabelled seed in my stock. Turns out the seed was still viable and intentions of thinning later (if required) never came to pass.
Like most evil spots in the garden, chocolate spot is a fungus. It begins as a harmless looking reddish/ brown spot, that will, if conditions carry on, expand and turn chocolate brown then black. Leaves and flowers shrivel, and if the stem gets streaky you’re heading for plant collapse.
Alternating wet and dry periods show up as concentric circles as the fungus does a stop go, stop go dance. Should the weather dry out, the fungus can loose it’s impetus. Dry? Unlikely at my place for a good few months yet, so I’m ruthlessly cutting out infected bits, even if it means pulling a whole plant. It’s worth it to save the rest. Airborne fungi like this spread like mad.
Needless to say, I’m also (finally) thinning my crop. Infected foliage hits the bonfire as I go, burning up the raspberry and rose prunings and providing me with a lovely pile of potash which I’ll sprinkle around the remaining plants. Potash is highly mobile and the next rain (we won’t wait long!) will flush it through. Is it too late for such amendments? Probably, but in a rescue one pulls out all the stops.
The real blow is the impact on flowering which means, of course, an impact on fruiting. Luckily I have loads of flowers and thus far a whole row unscathed.
Beans impacted by the fungus will be slightly discoloured. They’re perfectly safe to eat, but no good for seed as the disease can carry over.
Cure in this case, being the bottom of the cliff. But worth a look see if it means saving a crop!