Poor Broadbeans.

Lardman not quite sure whether the damage you describe is bean / pea weevil. Pea/ beanweevil adults eat very distinct notches (half-circles) out of the leaves, the larvae eat the underground  nitrogen fixing nodules (that are found on legumes (peas and beans)) later in the year. Do you have a problem with pidgeons ? Low yield of beans in previous years might be connected to a cool summer and less pollination by bumbelebees and thus less beans. In my experience damage by bean weevil will not really influence the yield too much.

Also in reply to another post nipping out the top of growing plants helps against black fly (aphids) but has no effect on bean weevils.

Lardman not quite sure whether the damage you describe is bean / pea weevil. Pea/ beanweevil adults eat very distinct notches (half-circles) out of the leaves

It is - as you say its very distinctive.  Flying rats aren't really a problem here, too many cat 

Its the sand box Im trying to grow in, I know it is... its just too sandy to hold any moisture and the beans show that more than anything else I grow.  The dry start has retarded then and the pests are having a field day.