I have a lot of tops on my potato plant but a very poor yield in potatoes I think that I have too much nitrogen in my soil. Could this be my problem and if so how can I remove it ? Pierre
Yes, excessive nitrogen or fertilizer application at the wrong time could be a cause, but there are other possibilities. This article discusses nutrient imbalance in potatoes:
High temperatures in the soil (such as when growing in containers or with black mulch) can also inhibit potato production, and very hard soil or drought can cause the potatoes to be too small (since they have trouble expanding).
Here are some other potato articles which might help: