Comparison of conventional and alternate-row pruning in four red raspberry cultivars

Many berry producers in Eastern Canada are reluctant to grow red raspberries because of higher labour requirements and the costs associated with pruning. Pruning (to alter cane density) also directly affects yield and fruit size through interaction of highly correlated yield components such as cane density, number of fruit per lateral and fruit size. This study was conducted to determine whether mowing canes would produce yields comparable with annual pruning. The effects of conventional (i.e. annual) and alternate-row pruning were compared at Cambridge Research Station, the University of Guelph, for three seasons using four red raspberry cultivars, while attempting to maintain cane density close to 15 canes per row. The four cultivars studied responded similarly to treatments for all traits except cane diameter. Yield per plot was not significantly different because of differences in cane density. Yield per cane was increased 28% on average by the alternate-row treatments. Yield per cane was significantly higher in the alternate-row scheme. Canes were taller in the conventional treatment for all three years. Canes in the alternate-row treatment tended to have greater cane diameters although the difference was significant only in 1980. Lateral number per cane and fruit per lateral were not significantly affected by pruning treatments. Alternate-row pruning has the potential to produce high yields per cane if the cane density control is practised. Increasing cane no. per ha by narrowing the between-row distances in the alternate-row scheme could greatly improve yields.