Articles
Chilling requirements for flowering of the North American pawpaw (Asimina triloba)
Article number
1460_17
Pages
141 – 146
Language
English
Abstract
The North American pawpaw (Asimina triloba [L.] Dunal), the only temperate member of the tropical Annonaceae family, is a native fruit tree with a natural range extending from the midwestern to southeastern United States (USDA Zones 5-8). As cultivation expands beyond its native range into Europe and Asia, understanding bud dormancy and chilling requirements becomes increasingly important for successful production.
Bud dormancy progression during winter plays a critical role in determining the timing and quality of budbreak, flowering, and fruit set in temperate fruit species.
An initial two-year study using the cultivars ‘Sunflower’ and ‘Susquehanna’ estimated chilling requirements for 30% flower budbreak using the chill hour and Utah models, revealing similar needs of 802 and 861 chilling units, respectively.
A subsequent evaluation of 12 additional pawpaw cultivars from across the northern and southern portions of the species’ native range showed relatively consistent chilling requirements for flowering, ranging from 648 to 749 chilling units to achieve 25% flowering.
All cultivars examined required between 648 and 861 chilling units to flower.
This narrow range of chilling requirements across geographically diverse cultivars suggests a relatively uniform dormancy response within the species.
Further research is needed to better understand the dormancy mechanisms of pawpaw, particularly in the context of climate variability and geographic expansion of cultivation.
Bud dormancy progression during winter plays a critical role in determining the timing and quality of budbreak, flowering, and fruit set in temperate fruit species.
An initial two-year study using the cultivars ‘Sunflower’ and ‘Susquehanna’ estimated chilling requirements for 30% flower budbreak using the chill hour and Utah models, revealing similar needs of 802 and 861 chilling units, respectively.
A subsequent evaluation of 12 additional pawpaw cultivars from across the northern and southern portions of the species’ native range showed relatively consistent chilling requirements for flowering, ranging from 648 to 749 chilling units to achieve 25% flowering.
All cultivars examined required between 648 and 861 chilling units to flower.
This narrow range of chilling requirements across geographically diverse cultivars suggests a relatively uniform dormancy response within the species.
Further research is needed to better understand the dormancy mechanisms of pawpaw, particularly in the context of climate variability and geographic expansion of cultivation.
Authors
K.W. Pomper, A. Chaudhary, J. Vincent, J.D. Lowe, S.B. Crabtree
Keywords
chilling units, tree fruit, flowering, Annonaceae, Utah model
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