`Prime-Jan' (`APF-8') and `Prime-Jim' (`APF-12') Primocane-fruiting Blackberries

Prime-Jan (APF-8) and Prime-Jim (APF-12) are the first commercial cultivars of primocane-fruiting blackberry (Rubus subgenus Rubus). Prime-Jan resulted from a cross of Ark. 1836 × Arapaho, whereas Prime-Jim was obtained from Arapaho × Ark. 830, and both were developed in Arkansas, USA. This unique type of blackberry fruit on current-season canes (primocanes) and second-season canes (floricanes). All other existing blackberry cultivars fruit only on floricanes, requiring canes to be overwintered to produce a crop. This new type of fruiting habit has the potential to revolutionize blackberry production much like that occurring in primocane-fruiting red raspberries (R. ideaus). These first primocane-fruiting cultivars are intended primarily for home-garden production, and for limited commercial trial evaluations.