My green bean (bush type) fruits are very short and curved. Soil test reveal that salts are present in high amounts. Is this the cause of the problem? Not enough water? (just re-set the dripper to provide more) What about a recent cool spell? The manure I had been using has some residual herbicide (Milestone) and the foliage does not look quite normal. But there are plenty of blossoms. The fruit just does not develop fully. Beans are VERY short (about 2 inches) and curved.
It seems you have a few issues going on and that to be successful will need to be addressed.
The salts in the soil certainly are an issue. It can be as simple as flushing the soil with water. Unconditioned water is the best to use.
Residual herbicides generally dissipate over time.