Support systems can be used to advantage with brambles to minimize loss of crop due to wind damage and to facilitate harvest and other cultural practices. Thornless blackberries will have higher yields when supported.
A wire trellising system is most practical where the hedgerow type of culture is used. The crossarm, two-wire system is common. Posts are set about every 20 feet with 3-1/2 to 5 feet remaining above the ground. Near the top of each post is nailed a crosspiece about 18 inches long. A wire is attached to the end of the crosspiece and run along each side of the row. The canes are trained between the wires or tied to them. Wire clips, used between the posts, will keep the wires from spreading.
A two-wire (one above the other) trellis may also be used. It is most useful with red raspberries and trailing blackberries. Posts are set the same manner as for the cross-arm trellis, but no crosspieces are used. One, two, or three single wires are strung between the posts. The individual canes are tied to these wires following dormant pruning.
A systems approach infers a specific cultural system that can be for a particular market. A description of several types of cultural systems follows.
There are similar results for summer red or purple raspberry systems as described previously. Tall and vigorous red or purple cultivars will require a trellis for support as they may reach six to seven feet in height.
Alternate-Year or Alternate-Row Mowing
In New York, when 'Titan' red raspberries were mowed, they were 89% as productive,
and when 'Royalty' purple raspberries were mowed, they were 67% as productive
as hand-pruned systems over a two-year period. Where a trellis is used, the
posts and string are removed and replaced after mowing.
In most cases, the fall raspberry system is harvested in August/September in Ohio. We recommend applying a lime sulfur spray in mid-March and mowing the plants within several days of the spray. Prior to mowing, posts and string are removed and then replaced after mowing. Mowing close to the ground is recommended. This system can be used for pick-your-own, hand, or mechanical harvest. Marketing raspberries in August/September can be difficult because customers may not be aware of the availability of berries, and customers are unavailable for harvest due to the beginning of primary and secondary school and vacation time during Labor Day.
5. Single trellis (two or three vertical wires).
Thornless blackberries are vigorous and require a trellis. Primocanes are tied to two or three wires in March. Wires are fastened to treated posts at three feet and at five feet. The vigorous main shoot may be allowed to grow along the top wire either to the next plant or past the next plant.6. Single- or double-T trellis (three to four horizontal wires).
A single-T trellis has two horizontal wires at five to six feet from the ground. A double-T trellis has one set of two horizontal wires at four feet and another at six feet from the ground. The wires are generally three to four feet apart on both Ts. Canes are headed at six feet in the summer, and these top laterals may not be pruned but are trained on the double T. Canes are generally not tied, whereas unpruned laterals are tied to wire.