I have many paw paw trees growing in my back yard in northern Indiana. Of all the trees only one is bearing fruit. Is there anything I can do to help the others to bear fruit?
The Wikipedia article here says the most common cause of poor fruiting is
Pawpaw flowers are insect-pollinated, but fruit production is sometimes limited as few if any pollinators are attracted to the flower's faint, or sometimes non-existent scent. The flowers produce an odor similar to that of rotting meat to attract blowflies or carrion beetles for cross pollination. Other insects that are attracted to pawpaw flowers include scavenging fruit flies, carrion flies and beetles. Because of irregular fruit production, some believe pawpaw plants are self-incompatible, requiring cross-pollination between trees of different clones (patches).
It then goes on to indicate that dedicated growers
often resort to hand pollination or to use of pollinator attractants such as spraying fish emulsion or hanging chicken necks or other meat near the open flowers to attract pollinators.
Despite the good taste and yield of the fruit members of my house would not stand for hanging meat in trees so I wish you luck!
Consulting with your local gardening society or extension service will provide you with local information.