Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2003
Publication Date: 6/1/2003
Citation: TAKEDA, F., HUMMELL, A.K., PETERSON, D.L. THE EFFECTS OF CANE NUMBER ON YIELD IN 'CHESTER THORNLESS' BLACKBERRY ON THE ROTATABLE CROSS-ARM TRELLIS. HORTSCIENCE. 2003. 38(3):377-380 Interpretive Summary: There is increased interest in growing blackberries in the United States for fresh market. We developed an unique trellis system to improve fruit harvestability. In this study we determined the effect of different numbers of primocanes on vegetative and fruiting capacity of 'Chester Thornless' blackberry. The results of our studies suggested it is the number of lateral branches, not the primocane numbers, that is more important determinant of plant performance and productivity. Limiting cane training to two or three canes that developed early in the season reduced labor for plant maintenance and meant that summer cane training can be completed prior to labor-intensive fruit harvesting. Management strategies that will not conflict with harvest operations or mitigate labor costs or scarcity of labor will improve the economic viability of eastern thornless blackberry.
Technical Abstract: We used mature 'Chester Thornless' blackberry plants trained to the rotatable cross-arm (RCA) trellis to determine the effect on retaining two, four, and six primocanes on plant productivity. Retention of only the two oldest primocanes and generally the most vigorous primocanes per plant yielded 14.1 kg of fruit compared to 17.1 kg per plant in which as many as six primocanes were retained. Increasing the number of canes retained did not result in yield increase (p = 0.09) because the primocanes trained in late-June and July produced only a few, and, in some cases, no lateral branches. Thus, limiting the number of canes for training to those that become trainable early in the season decreased labor inputs and allowed primocane training to be completed prior to the onset of harvest. As a result, the effort to train and retain only those primocanes that reach the trainable height before mid-June may be advantageous to minimize labor costs. However, profit potential is higher when more canes are left.