Scheduling primocane-fruiting raspberries (Rubus idaeus L.) for year-round production in greenhouses by chilling and Summer-pruning of canes

Abstract

SummaryTwo greenhouse experiments were performed to investigate the effects of Summer-pruning in the first year, and cold-storage, on primocane-fruiting raspberry (Rubus idaeus L.) cultivars. In the first year in the greenhouse, primocanes were Summer-pruned when they were 60 cm tall which delayed fruiting by approx. 1 month, but decreased yields slightly. Plants cold-stored below 7°C for 6 weeks, markedly and consistently out-yielded those that had not been cold-treated. In the second experiment, yields on the floricanes and primocanes were separated and clearly showed that floricane dormancy was broken, so that double-cropping could occur. ‘Heritage’ produced few fruits on its floricanes, which indicated that it requires a longer cold treatment than cvs. ‘Autumn Britten’, ‘Polana’ and ‘Summit’. In this system, 10 canes m–2 appeared to be the optimum number of primocanes needed to produce the highest yields. These experiments confirmed that adventitious buds will eventually break dormancy without a chilling period, as daylength increases. Also, they show that primocane-fruiting raspberries can be manipulated to fruit all-year-round in the greenhouse.