Growing Magazine - May, 2013

COLUMNS

Orchard Management: Planning for a Tall Spindle Orchard

By Sally Colby

If you think it's too late in the season to start planning a tall spindle (TS) orchard, Dr. Mario Sazo would disagree. Sazo, a Cornell Cooperative Extension associate for tree fruits and berries, said it takes at least two years to plan an intensive orchard production system.



Remote-controlled GPS equipment can be used in tall spindle orchards because trees are planted at precise intervals.
Photos by Sally Colby.

"There isn't one recipe for establishing a tall spindle system," said Sazo, who has heard a litany of reasons for not starting a TS orchard from growers who balk at the expense and initial labor involved. Those reasons include too much work, insufficient help and not owning the equipment necessary for working in narrow alleys. Sazo agreed that the expense involved in starting up a TS planting is significant, and in some cases the grower who does the initial work won't be the one who sees the profits.

"The challenge when considering a TS planting is figuring out how to balance efficiency with resources such as time, water, soil and light," Sazo remarked. "But flexibility is also important."

Inadequate soil and drainage preparation, late planting and using homegrown nursery stock are common mistakes made by first-time TS growers. Shortcuts that lead to a poor outcome include trying to establish a TS orchard with short posts, not irrigating, and installing the tree support system too late, which results in minimal leader growth.

Although the tall, strong trellises necessary for supporting a TS orchard are costly, they should be viewed as an investment. Twelve-foot posts ensure that trees are adequately supported as they approach the top trellis wire. Trees should reach the top wire, which is placed at a 10-foot height, by the end of the second or third year. Adequate support allows fruit production in the early years while preserving the vertical trunk and canopy.

Sazo said that although some TS orchards are successfully established in spring, fall is more ideal. "Plant trees in early fall to allow roots to become established. Irrigate soon after planting to get optimum growth in the first two or three years," he advised.



Harvest-assist equipment, including platforms, is a worthwhile investment for tall spindle orchards.

If apical dominance has been interrupted in the nursery, the growth stimulated in the orchard will become the main leader. At some point there will be long feathers, but the goal is short feathers. Sazo said the ideal tree has a 5/6-inch caliper and eight to 10 short feathers. Each feather should be 10 to 16 inches long, and the first feather should be about 24 to 26 inches aboveground. Feathers should be well-distributed on the tree.

With GPS technology, TS plantings can be established to maximize future mechanization. Precisely spacing trees the same distance apart leads to optimum branch development with uniform light availability and distribution. If branches begin to cross due to uneven planting distance, the grower may eventually see higher labor costs for pruning and correction.

Leader growth is key to achieving optimal height in a relatively short amount of time. Ideally, trees will add 2 or more feet of growth annually, but 16 to 19 inches is good. "This is critical because the lack of leaders in a cultivar like Honeycrisp limits future yield," said Sazo, noting that it's a lot more difficult to manage low-vigor cultivars than high-vigor cultivars like Gala, Fuji or McIntosh. "You can make a lot more money early in the life of the orchard if you fill the structure of the tree."

Weak cultivars, such as Honeycrisp, should be planted closely, at 3 feet or less, with vigorous M.9 clones (Pajam 2, Nic 29) or G.41, which is comparable to large M.9 clones and resistant to fire blight. "The main goal for the first season is to keep the leader growing and achieve 18 to 24 inches of shoot growth through late July through intensive water and nitrogen management," Sazo said.

He noted that trees coming from the nursery have a limited root system and are subject to transplant shock. These young trees have less ability to take up nutrients until roots become more developed. Trees with a lot of feathering often experience water stress in late May and June due to limited root systems and expanding leaf area.

Trickle irrigation has the largest impact in the first few years and should be installed within two weeks of planting. New plants should be irrigated two to three times a week, unless there is at least 1 inch of rain that week. Each irrigation should be low-volume, about 2 to 3 gallons per tree. Fertigation with liquid nitrogen fertilizer is an ideal means of delivering adequate nutrition to the tree and will encourage leader growth.

Through extensive research in establishing TS orchards, Sazo and his colleagues have found that a three-wire trellising system with accompanying vertical support, such as pipe, bamboo or wire stabilizer, works well. If no vertical support is used, growers should plan to use four or five trellis wires. Leaders should be secured to the trellis with a band or plastic loop as soon as they reach the next wire.

Sazo said the impact of grower mistakes is higher in high-density plantings than in low-density plantings. He emphasized the importance of not heading the leader and using a bevel cut to remove feathers that measure more than two-thirds of the diameter of the leader. If trees have fewer than three feathers, remove them all with a bevel cut, then treat the tree as a whip and use MaxCel 15 to 20 days after bud break to promote branching.

Establishing a TS orchard is a matter of determining whether the production model is right for each operation, and realizing that there is a significant financial cost and labor requirement until the planting is established.

"You don't have to continue doing what you've been doing for 20 to 25 years," said Sazo. "Think outside the box to see the opportunities to make money. But don't do it if you aren't ready - do it right from the get-go."

The author is a frequent contributor and freelance writer who farms and raises Great Pyrenees in south-central Pennsylvania. Comment or question? Visit www.farmingforumsite.com and join in the discussions.