I'm not sure what the cause is and would welcome any suggestions you all might have!
I've not had much problem with the beans. They were sown last november and have over wintered. This is the same way I grew them last year without problem. The winter this year was milder but not much with temperatures dropping to minus 10°C or about 15°F. This spring the weather has been unusually warm and dry with virtually no rain over the past two months until this week when we have had about 15mm (1/2 inch)
I had a slight problem with black fly which I treated by spraying with a white horticultural spray following a recipe given to me by Kate, mixing sunflower oil with a mild liquid detergent. The resulting solution was diluted before use by adding two tablespoons solution to 2 litres water (1/2 Gal US). I sprayed three times every third day
The photo isn't very clear but you can see the black slime inside the pod. Some beans had just one end affected whilst others had the entire bean affected. I guess about 10% of the crop was affected. The beans are planted in a different bed each year and have never yet returned to a previous site.
I look forward to reading your comments. Many Thanks