Comparative Analysis of Pawpaw Production Data from 2005-2012 A thesis presented to the faculty of the College of Health Sciences and Professions of Ohio University In partial fulfillment of the requirements for the degree Master of Science Laine M. Greenawalt August 2016 © 2016 Laine M. Greenawalt. All Rights Reserved. 2 This thesis titled Comparative Analysis of Pawpaw Production Data from 2005-2012 by LAINE M. GREENAWALT has been approved for the School of Applied Health Sciences and Wellness and the College of Health Sciences and Professions by Robert G. Brannan Associate Professor of Applied Health Sciences and Wellness Randy Leite Dean, College of Health Sciences and Professions 3 Abstract GREENAWALT, LAINE M., M.S., August 2016, Food and Nutrition Sciences Comparative Analysis of Pawpaw Production Data from 2005-2012 Director of Thesis: Robert G. Brannan Introduction: This study examined fruit production characteristics of different varieties of pawpaw (Asimina triloba) over a period of 8 years. Methods: Plants of 52 varieties of pawpaw (n = 359) were planted at three locations in southwest Ohio from 2001-2006. Fruit were collected and weighed spring 2005-fall 2012. For further analysis, the 52 varieties were divided into two data categories (varieties not belonging to a genetic group and those assigned a genetic group) based on previous research. Differences in average fruit weight (g), yield (g), and harvest length (days) were analyzed among varieties and genetic groups. Pearson’s r was used to identify any correlation between average fruit weight and total number of fruit produced. Results: Significant differences in average fruit weight were found between genetic groups and individual varieties. Differences in yield and fruit onset were also identified between individual varieties. Significant differences in average fruit weight and yield were seen between growing locations. Comparison of average fruit weight and total fruit number resulted in a significant negative correlation. Discussion: Results indicate that some pawpaw varieties, or groups, generate significantly larger fruit. Results also indicate that planting location makes a difference in fruit production, although future research is needed to identify specific growing factors. A weak negative correlation between average fruit weight and total fruit number indicates that large fruit sets can lead to decreased fruit size. In order to 4 improve fruit quality and tree productivity, potential pawpaw growers must consider many preharvest factors. These findings add to the limited body of evidence about pawpaw fruit in general and indicate that variety and growing location can significantly affect the ultimate commercial potential of pawpaw fruit. 5 Preface The manuscript has been formatted to meet the guidelines set forth by the Thesis and Dissertation Services at Ohio University. Chapter 3 contained within this APA- formatted thesis document serves as a prepublication manuscript which follows the structure of the International Journal of Fruit Science. 6 Dedication This work is dedicated to my friends and family, who have supported me throughout the writing process. 7 Acknowledgments I would like to acknowledge Dr. Ron Powell, for providing me with the data that made this project possible, and my committee–Dr. Robert Brannan, Dr. Janet Simon, and Dr. Art Trese, for their continuing support and guidance. 8 Table of Contents Page Abstract ............................................................................................................................... 3 Preface................................................................................................................................. 5 Dedication ........................................................................................................................... 6 Acknowledgments............................................................................................................... 7 List of Tables .................................................................................................................... 10 List of Figures ................................................................................................................... 11 Chapter 1: Introduction ..................................................................................................... 12 Overview and Background ........................................................................................... 12 Statement of Problem .................................................................................................... 14 Significance .................................................................................................................. 14 Limitations and Delimitations ...................................................................................... 15 Glossary ........................................................................................................................ 16 Chapter 2: Review of Literature ....................................................................................... 18 Introduction ................................................................................................................... 18 Background ................................................................................................................... 18 Morphology .................................................................................................................. 21 Fruit Characteristics ...................................................................................................... 27 Development of the Pawpaw Industry .......................................................................... 32 Commercialization ........................................................................................................ 36 Chapter 3: Comparative Analysis of Pawpaw Production Data from 2005-2012 ............ 40 9 Abstract ......................................................................................................................... 40 Introduction ................................................................................................................... 41 Materials and Methods .................................................................................................. 43 Results ........................................................................................................................... 46 Discussion ..................................................................................................................... 58 Conclusion .................................................................................................................... 62 Literature Cited ............................................................................................................. 65 Chapter 4: Summary and Conclusion ............................................................................... 69 References ......................................................................................................................... 72 Appendix A: Descriptions of Pawpaw Cultivars Used in this Study................................ 83 Appendix B: Sample Data Collection Sheet ..................................................................... 91 Appendix C: 8 Varieties of Pawpaw Excluded from All Data Analysis .......................... 92 Appendix D: Means ± SDs for 52 Individual Varieties Included in Data Analysis ......... 93 Appendix E: Pictures of Planting Locations ..................................................................... 95 Appendix F: Original Data Recorded by Ron Powell ..................................................... 95 10 List of Tables Page Table 1: Research Questions and Hypotheses ................................................................14 Table 2: Proximate Analysis of Common Fruits ............................................................31 Table 3: Genetic Grouping of Pawpaw Varieties ...........................................................34 Table 4: Mean Average Fruit Weight, Yield, and Harvest Length (Means ± SDs) for 52 Pawpaw Varieties by Year ..................................................................................51 Table 5: Mean Average Fruit Weight, Yield, and Harvest Length (Means ± SDs) for Three Data Categories: 52 Pawpaw Varieties, Varieties Not Belonging to a Genetic Group, and Those Varieties Belonging to a Genetic Group ..................52 Table 6: Mean Average Fruit Weight, Yield, and Harvest Length (Means ± SDs) for Pawpaw Genetic Groups .....................................................................................52 Table 7: Mean Average Fruit Weight, Yield, and Harvest Length (Means ± SDs) for Pawpaw Varieties Not Belonging to a Genetic Group by Year..........................54 Table 8: Mean Average Fruit Weight, Yield, and Harvest Length (Means ± SDs) for Pawpaw Varieties Belonging to a Genetic Group by Year .................................55 11 List of Figures Page Figure 1: North American pawpaw’s native growing range ...........................................19 Figure 2: USDA plant hardiness map .............................................................................20 Figure 3: Pawpaw flower ................................................................................................23 Figure 4: Pawpaw fruit....................................................................................................25 Figure 5: Pawpaw