To help meet the demand for lower-chill, machine harvestable blueberry varieties, research continues to come up with possible solutions for growers to pick from. The latest selections coming out of the UF/IFAS Blueberry Breeding Program (‘Keecrisp’ and ‘Patrecia’) aim to please.
‘Keecrisp’ resulted from a cross made between ‘Sweetcrisp’ and ‘Indigocrisp’ made in 2003, and was tested as ‘FL06-556.’ The selection was released earlier this year and a U.S. Plant Patent was applied for in March.
‘Keecrisp’ is the latest release in the series of “crisp” varieties from the UF/IFAS breeding program. This crisp fruit texture has been shown in trials conducted at the University of Florida and the University of Georgia to be important for machine harvest for fresh marketing potential of a variety.
In postharvest storage and quality trials conducted with Dr. Anne Plotto at USDA’s Horticulture Research Lab in Ft. Pierce, ‘Keecrisp’ and the similar crisp texture variety ‘Indigocrisp’ had the highest firmness ratings at harvest and after two weeks storage compared to standard texture varieties such as ‘Emerald.’
Crisp fruit texture also allows fruit to be held on the bush longer between harvests before quality degrades, which is an important management tool to make machine harvest more efficient.
‘Keecrisp’ is a vigorous, upright-growing bush with long, somewhat whippy canes when grown under the summer hedging management used in southeastern southern highbush blueberry production. The estimated chill requirement for ‘Keecrisp’ is 300 or more hours below 45°F. This is based on inconsistent cropping and vegetative budbreak in areas south of Gainesville, FL, that receive less than an average of 300 chill hours in a season. ‘Keecrisp’ does respond favorably to hydrogen cyanamide application with a condensed bloom period and earlier prolific leafing, but appears to be sensitive to rate and timing similar to its parent ‘Sweetcrisp.’
The average 50% bloom date of ‘Keecrisp’ near Gainesville, is February 14, similar to ‘Farthing’ and ‘Star,’ and approximately a week later than ‘Emerald’ and ‘Meadowlark.’ Like most southern highbush blueberries, planting additional varieties for cross pollination is recommended to achieve the best fruit set on ‘Keecrisp.’
‘Keecrisp’ ripens mid- to late-season, with an average 50% ripening date of May 5. As the majority of the harvestable crop comes after the high-value period in Florida, the greatest potential for ‘Keecrisp’ will likely be as a machine-harvestable variety that can be fresh-marketed in the more northern production areas of Florida.
‘Keecrisp’ berry size is large with a small, dry stem scar. ‘Keecrisp’ berries have high soluble solids and consistently low titratable acidity in laboratory trials that result in a mild, very sweet flavor.
Also available first in 2016 is the early-season southern highbush variety named ‘Patrecia.’ This variety was initially developed by Straughn Farms, but is being commercialized by UF/IFAS in cooperation with Straughn Farms. ‘Patrecia’ resulted from a cross between ‘Star’ and ‘Springhigh,’ and retained some of the most desirable characteristics from both parents — early season production and short bloom to ripe period. ‘Patrecia’ has a spreading growth habit, with high yields of large fruit in clusters that are quite easy to hand-harvest. ‘Patrecia’ has not been trialed in Central and South-Central Florida, so adaptation to these areas is unknown. ‘Patrecia’ has responded well to hydrogen cyanamide applications, with condensed bloom periods and rapid, prolific vegetative budbreak.
Initial budwood distribution of both ‘Keecrisp’ and ‘Patrecia’ is limited, so licensed propagators are strongly encouraged to establish a mother block that can be maintained as a source of cutting material for future propagation.
‘Keecrisp’ and ‘Patrecia are protected varieties and a license must be obtained for propagation and sale of plants. License information can be obtained from Florida Foundation Seed Producers (FFSP).