Development of optimal rose canopy management strategies for California growers: “bending ” versus “traditional ” production where are the profits?

Traditional cut-flower rose production involves growing plants in the ground and training the canopy vertically as a tall hedge (Langhans, 1987). Since the hedge gets taller as the succeeding harvests are made above the origin of the flowering shoot, the height of canopy requires periodic pruning (Durkin, 1992). In recent years rose growers have begun to replace these practices with shoot-bending where non-productive shoots (weak stem caliper, potential blinds) are bent down into the canopy or towards the aisle. The fundamental idea behind shoot-bending is that instead of removing unwanted or marginal stems by pinching or pruning, these are retained in the canopy so as to maintain foliage area and consequently produce assimilates. In traditional production, a tall hedgerow canopy assures ample foliage area to capture light. With shoot-bending, it becomes possible to maintain the low canopy height without sacrificing foliage area. It has been reported that bending of the primary shoot promotes the formation of axillary shoots by breaking apical dominance (Cline, 1991). Zieslin and Halevy (1978) found that in roses bending the stem caused growth of a strong shoot close to the bend and another strong shoot close to the distal end. Kool and Lenssen (1996) reported that timing of bending affects the vigor of renewal canes developing from the basal parts of the plant (“basal-shoots”) and tha