Knowledge Bank

The pawpaw (Asimina triloba) is a small fruit-bearing tree in the Annonaceae family, known for being the only tree native to the United States that bears large edible fruit (Callaway, 1990). These trees are of high cultural importance to the state of Ohio and the surrounding region for their history as a reliable and nutritious food source, an indicator of good ecological condition and, due to their clonal growth, effective erosion control. Although common in the region, fruit production is often limited, and large-scale cultivation and commercialization has not been historically successful. To determine what affects fruit production in the wild, we studied the environmental conditions of 10 different pawpaw patches in Columbus, Ohio. Five plots were located at the Olentangy River Wetland Research Park, and five at Waterman Farm, both sites managed by The Ohio State University. We assessed tree height, basal diameter, evidence of damage, and counted the number of primary branches, flowers and fruits. We also recorded woodland canopy cover and invasion by non-native woody vegetation. We monitored 377 trees in total; the mean number of flowers was 43.69 and the mean number of fruits 1.93. However both of these varied substantially at the tree level with flowering effort ranging from 0 to 274 and fruit production from 0 to 42; 265 of the 377 trees examined did not have fruit. We used a Linear-Mixed Effect Model to assess controls on tree-level flower and fruit production. Variation between plots was large but tree age, as indicated by diameter, was a tolerable predictor. Further analysis will determine the relationships between other factors, and to examine fruit production at the plot level. Our analysis provides a starting point for more research regarding how to better manage woodland pawpaw patches for fruit production. For example, understanding the influence of tree diameter on fruit production can help determine management practices for stand structure such as spacing, thinning, or burning. This information will help continue renewed interest in effective pawpaw cultivation and also create a more reliable local food source.