Method for producing tip-layered, long-cane blackberry plants using the rotating cross-arm trellis and cane training system

Authors: Takeda, Fumiomi; SORIA, JORGE - National Agricultural Research Institute(INIA)

Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/2011
Publication Date: 11/15/2011
Citation: Takeda, F., Soria, J. 2011. Method for producing tip-layered, long-cane blackberry plants using the rotating cross-arm trellis and cane training system. HortTechnology. 21(5):563-568.

Interpretive Summary: Blackberry plants have not been grown commercially in areas that lack cold winter temperatures because the plant must be exposed to cold temperatures for flowering shoots to develop normally and bloom. We used ARS-developed rotating crossarm (RCA) trellis and cane training system to produce blackberry plants that would produce fruit within 6 months of establishment in protected environment or in areas with sub-tropical conditions. As much as six times more long lateral canes can be produced on blackberry plants trained to RCA trellis than on plants trained to conventional post and wire trellis system. The long cane plants produced on plants trained to the RCA trellis system were cold-stored up to 41 days before they were transferred to a heated environment. Flowering shoots emerged from 75 percent of axillary buds of 'Siskiyou' blackberry, of which 15 percent terminated in a flower within 2 months in the greenhouse. Budbreak percentage in Triple Crown was low and none of the shoots produced a flower. As many as 60,000 long-cane plant production can be generated from 1 acre nursery site. The long-cane potted plants are suitable for off-season fruit production in the greenhouse when domestic production is non-existent and can be grown in sub tropical areas where chill hour accumulation is insufficient for blackberry production.

Technical Abstract: The rotating cross-arm trellis and a unique cane training technique was used to produce 5- to 6-ft-long tall-cane plants of semi-erect (cv. Triple Crown) and trailing (cv. Siskiyou) blackberries. The primocanes were bent to grow horizontally at 18 in height and the lateral canes that developed on the horizontal portion of the primocanes were trained to grow vertically on wires on 5-1/2-ft long rotating cross-arm. The lateral canes draped over the top most wire and then grew downward to two-liter pots on the ground. Cane tips were placed in the peat-based substrate as they approached the ground from mid August to early September. The adventitious roots developed at the tip and filled the 2-L container in 3 weeks. The tip-rooted lateral canes were cut from the mother plant at the top trellis wire in early October and maintained as follows: transplanted in 8 L (approximately 2.1 gal pot, grown in an unheated greenhouse for 1 month, stored at 44 degrees F for 29 or 41 days and then moved into an environmental (72 degrees F) chamber for growth measurements. After 4 weeks 76 percent of buds had broken in 'Siskiyou', but less than 30 percent in 'Triple Crown' blackberry. Flowering shoots developed in 15 percent of the tall canes of 'Siskiyou' plants produced fruiting laterals in January, but axillary shoots that emerged from the tall-cane 'Triple Crown' vegetative and flower buds were absent.