Abnormal growth and light green-spotted or streaked leaves on French beans are usually the signs of virus infestation.
If these phenomena occur strongly before the bush beans are in bloom, then a significant harvest can hardly be expected. The only remedy against this disease is to destroy the affected plants immediately. French beans, showing the characteristics mentioned, must not stop to collect seeds or dry beans. After the pods have been harvested, all parts of the plant must be burned completely.