Selection of Primocane Fruiting Blackberries Using Organic Practices

Study conducted by Kirk W. Pomper, Jeremy Lowe, and Sheri Crabtree

Primocane fruiting blackberries have the potential to produce a niche-market crop for Kentucky growers from late summer until frost. This type of blackberry fruits on current-season canes (primocanes).The first commercial primocane-fruiting blackberry varieties, Prime-Jim® and Prime-Jan®, were released by the University of Arkansas in 2004. All previous blackberry varieties are floricane-fruiting, thus the canes must be overwintered for fruiting the second year. 

This new type of blackberry has the potential to produce more than one “crop” per year, having the potential for the normal summer crop (floricane) and a later crop on the current season primocanes. These primocane fruiting blackberries flower and fruit from late summer until frost, depending on temperatures, plant health, and the location in which they are grown. Primocane blackberry selections can be pruned by mowing the canes down in the winter; this also provides anthracnose, cane blight and red-necked cane borer control without pesticides.

The objective of this project is to determine if advanced selections developed by the University of Arkansas Blackberry Breeding Program are superior to Prime-Jim® and Prime-Jan® in terms of flowering and yield under Kentucky growing conditions and following organic production practices.

In June 2006, the trial was established at KSU and includes both primocane and floricane fruiting selections. 

The floricane fruiting selections under evaluation are:

• Apache (thornless erect), 
• Chickasaw (thorny erect), and
• Triple Crown (thornless-trailing). 

The primocane fruiting selections are:

• Prime-Jim® (thorny erect, primocane-fruiting),
• Prime-Jan® (thorny erect, primocane-fruiting), and
• Arkansas Primocane Fruiting (APF) selections APF-27, APF-40, APF-41, APF-42, APF-46, and APF-77 (all thorny erect, primocane-fruiting) that are advanced selections from the University of Arkansas blackberry breeding program. 

Additional evaluation will be needed over the next several years before decisions are made on whether any APF selections will be released by the University of Arkansas.

Sources:

• 

  2008 Kentucky Primocane Fruiting Blackberry Results (1.5 MB pdf) - Grower presentation, 2008.
• The Kentucky Primocane Fruiting Blackberry Trial (1.5 MB pdf) - The 2007 University of Kentucky Fruit and Vegetable Crops Research Report.
• Recent PowerPoint Presentations on pawpaw, gooseberries and currants, and blackberries - KSU Pawpaw Website