The first primocane-fruiting blackberries, ‘Prime-Jan’ and ‘Prime-Jim’, were released in 2004 (Clark et al., 2005). This type of erect blackberry produces flowers and fruit on the first-year cane, the primocane, in addition to the second-year cane, the floricane. Primocane-fruiting blackberries may offer opportunities for season extension and off-season fruit production in both northern and southern hemispheres, particularly in mild climates. However, field observations have revealed that erect primocane-fruiting morphology is different from that of erect floricane-fruiting blackberry and primocane-fruiting raspberry (B. Strik, personal observation). Bloom pattern within an inflorescence and range in fruit maturity for semierect blackberries has been reported (Takeda, 1987). Fruiting lateral characteristics such as fruitfulness and node position have been described in red raspberry (Dale, 1979; Dale and Topham, 1980). Production guidelines for floricane-fruiting blackberries and primocane-fruiting raspberries are well established; however, to date, there are few reports on management guidelines for primocane-fruiting blackberries. Traditional cane management for erect, floricane-fruiting blackberries includes summer tipping of primocanes and winter pruning of floricanes. Tipping the upper portion of the primocane in early summer removes apical dominance and encourages branching. Similarly, soft-tipping (removing the upper 2 to 5 cm) primocane-fruiting types in early summer may be a feasible way to manage primocanes, to encourage branching, and to increase yield (Drake and Clark, 2003; Strik et al., 2007).
Studies are underway to determine optimal cane management practices in primocane-fruiting blackberry under mild climate conditions (Strik et al., 2007). Identifying the location of productivity within a primocane, bloom pattern among branches, and order of bloom within an inflorescence throughout the harvest season has not been done in this crop and is necessary to optimize primocane management to precisely target harvest off-season markets.
The objectives of this study were to: 1) characterize flowering location, inflorescence morphology, bloom pattern, and range of fruit maturation in primocanes of ‘Prime-Jan’ and ‘Prime-Jim’ grown in western Oregon; and 2) determine the impact of soft-tipping on flowering and fruit ripening patterns of primocanes.
Anonymous 2005–2006 U.S. Department of the Interior, Bureau of Reclamation, Boise, ID. Agrimet Weather Station web site 13 Nov. 2006<http://www.usbr.gov/pn/agrimet/wxdata.html>
Clark, J.R., Moore, J.N., Lopez-Medina, J., Finn, C. & Perkins-Veazie, P. 2005 ‘Prime-Jan’ (‘APF-8’) and ‘Prime-Jim’ (‘APF-12’) primocane-fruiting blackberries HortScience 40 852 855
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