Answer: The problem with low fruit set may be lack of pollination. If your patch isn't visited by honeybees or wild pollinators such as bumblebees, the pollen probably isn't making it from male to female flowers. You can enhance pollination by using a bee attractant (Gardens Alive sells one called Bee-Scent; contact them at 812/537-8650 or e-mail firstname.lastname@example.org). Otherwise, you'll have to do the pollen transfer yourself, using a cotton swab or a small paintbrush. I know that parts of the south are suffering from hot, droughty weather. Dry conditions can cause blossoms to drop, too.
It's fine to prune pumpkin vines in the home garden, or they will, as you've noticed, take over the whole place! Commercial growers don't bother because it's too labor intensive - they put their time and money into other yield-enhancing practices. Gardeners who are trying to grow giant pumpkins for competition prune vines, but in a very specific manner. In your garden, trim secondary vines (that grow off the main vine) to 6-10' with a shovel and bury the cut end in soil. If the buried end starts to sprout, pinch it back. Hope this helps!
Q&A Library Searching Tips