Response of Potted Red Raspberry Cultivars to Double-cropping under High Tunnels

Abstract

Red raspberry cultivars that produce fruit on current-season canes (primocanes) can produce additional fruit the following year as second-year floricanes, termed double-cropping. The purpose of this study was to compare raspberry cultivars for double-cropping potential in a potted growing system under high tunnels in southwest Michigan. The cultivars Encore (floricane fruiting only), Imara, Josephine, Kwanza, Kweli, Nantahala, Nova, and Prelude were grown for 3 years in 11-L pots under a high tunnel. ‘Imara’, ‘Kweli’, and ‘Prelude’ produced the greatest total yields, averaging 2.7 kg/plant during the last 2 years. ‘Imara’ and ‘Kweli’ also produced large fruit that retained high fruit quality after storage. ‘Prelude’ was the earliest to ripen floricane fruit, and ‘Encore’, ‘Josephine’, and ‘Nanatahala’ were the latest. The start of primocane fruit harvest varied by year, but ‘Prelude’ was consistently one of the earliest. Overall, maintaining potted plants for multiple years reduced the cost of annual replacement, but older plants managed for floricane and primocane fruit production required additional pruning and training to control vigor.