This is true. I believe the excess nitrogen is what the problem is. A good balanced fertilizer can be used in the beginning, but once the plants begin to blossom a fertilizer with much less nitrogen than phosphate and potassium is needed. More potassium and phosphate will help your plants develop fruit. If you add a nitrogen-rich fertilizer as this time, the plant will get very large but won't produce any fruit.Some plants - tomatoes, I know - need less nitrogen or they produce too many leaves and not enough fruit.