2019 ASHS Annual Conference
The Impact of Five Grafting Techniques on Success Rate in Pawpaw (Asimina triloba)
The Impact of Five Grafting Techniques on Success Rate in Pawpaw (Asimina triloba)
Tuesday, July 23, 2019
Cohiba 5-11 (Tropicana Las Vegas)
The pawpaw (Asimina triloba) is a fruit-bearing tree native to North America. Its increasing popularity, including among processors, retailers, and restaurants, has led to small-scale commercial production in the United States and worldwide. A large number of wild and seedling pawpaws grown by homeowners and small-scale farmers produce fruit of poor taste, quality, or size. A new advanced selection, Hi7-1, as well as recently released KSU-Chappell™ being studied at Kentucky State University (KSU) have received more favorable reviews for flavor, texture, and appearance than many commercially available varieties. KSU-Atwood™ is a trademarked cultivar developed at KSU that was released in 2009 and is available through licensed nurseries. Whip and tongue grafting and chip budding are common ways to grow desired pawpaw varieties on healthy rootstocks. Grafting can also be performed using tools such as the Topgrafter. T-budding is often used to propagate other fruit and nut species, but is commonly considered unsuccessful with pawpaw; however, this method has not been tested in a replicated study. The purpose of this study was to determine the optimal method and timing for grafting the pawpaw cultivars KSU-Atwood, KSU-Chappell, and Hi7-1. Potted two-year-old trees of each cultivar (n=4/cultivar) were grafted in May using each method (chip, whip & tongue, T-bud, and Topgrafter) at the KSU H.R. Benson Research and Demonstration Farm greenhouses. Additionally, trees were chip budded with green buds of either KSU-Atwood™ or KSU-Chappell™ (n=10) in August to determine the effectiveness of green bud grafting. At the end of the growing season, whip & tongue grafting was the most effective method with a 96% success rate and t budding was the least effective at 37%. Topgrafter and chip budding success rates were 67% and 54% respectively. Grafting success was not significant between different varieties. Survival rates after overwintering will be recorded and discussed.