A few inches above the graft union on these Gala knipboom trees, you can see the heading cut made at 24 to 27 inches where the central leader then grew out.
Five years ago, Charles "Chip" Bailey came back from an international tree fruit tour of Bolzano, Italy, excited about the tall spindle orchards he saw using knip-boom trees. But though he wanted to try planting a block, he couldn’t find any U.S. nurseries selling them.
Knip-boom or knip trees, popular with growers in Italy and France, come into production quickly because their roots are two years old and trees are well feathered when they are planted.
"After we decided that we wanted to plant a block of knips, the biggest problem was finding a nursery to partner with," said Bailey, who with his wife, Karla, owns KC Bailey Fruit Farms, growing fresh-market and processed apples in Williamson, New York.
Willow Drive Nursery in Ephrata, Washington, agreed to grow the Gala, McIntosh, and Honeycrisp knip trees the Baileys wanted. The knip trees, which had to be ordered two years in advance, were planted in spring 2007. The 2.5-acre block is trained to a tall spindle system and located next to a vertical axis block that will serve as a comparison control.
Chip had to design a trellis that would work with the tall spindle and support the trees that had such a "huge" top. "It’s been quite a learning experience because I was starting from scratch. Nobody is growing this system, so there was nobody to copy," he said, adding that he visited orchards at the New York Agricultural Experiment Station in Geneva to look at spacing of a vertical axis orchard being converted to a tall spindle.
Though the system is patterned after orchards Chip saw in Italy, he clarifies that what he has planted is a "translation" of Bolzano systems. "Sometimes, there are a few things lost in translation," he said, explaining that his trial is not identical to Italian orchards because he had to work with different trellis materials to make the system work. "But the concept is the same."
His knip trees are spaced 3 feet by 11 feet, with 1,320 trees per acre. Trellis wires keep the heavy-topped, feathered trees upright, and drip irrigation lines are clipped to the bottom trellis wire.
"After planting, Karla remarked to me that it was like an ‘instant orchard,’" Chip said. In 2008—the second leaf of the orchard—production was 200 to 300 bushels per acre of high-quality fruit.
"The first year was a challenge in getting enough water to the trees because they have such a huge top," he said. Water management is critical in getting trees established.
He notes that the biggest expense was for tying down limbs in the first year. The caliper of his branches was thicker than those he saw on Italian knip trees, which made training more difficult. But in the second year, the block needed little pruning.
From the start, he treated the trees just as he would a bearing orchard, following the same pest management and thinning programs that he does in mature orchards.
Chip has already learned that not all knip trees are the same. Honeycrisp knip trees are weaker and brittle compared to Gala and McIntosh. He was surprised that the weak fruiting spurs at the top of the McIntosh trees were helping to keep the trees "calm" and more manageable for the cone shape of the tall spindle.
The Baileys are interested in the tall spindle system as a way to maintain trees without extensive pruning. "You do more training up front, but after that, there’s a lot less pruning," he said.
He also wants to shorten the time to fruiting and bring down the age of the fruiting wood. "With the trend towards managed varieties, it’s even more important to shorten the age to fruiting," he said. "I’m trying to grow more fruit than firewood."
Initially, Chip was concerned about fruit size on the tall spindle trees. Much of the fruit grown in Italy is smaller than fruit in the United States to meet the smaller size requirements of the European market. But he found that if leaf-to-fruit ratios are in order, size isn’t a problem.
"It would be easy to overcrop these trees, whether they’re on Malling 9 or M.111 rootstock," he said. "If fruit is too close together, it’s too close together, and it doesn’t matter what rootstock or system you have them on."
Thus far, the Baileys are excited about the tall spindle block. Production was good in the second leaf, and the system seems to be working.
Cornell University’s Dr. Terence Robinson has a test block of the tall spindle system in New York’s Hudson Valley. Chip’s tall spindle block has been the site of several orchard tours, and he has received several inquiries from growers interested in the system.
"It’s a great thing when you get more people involved because then you get more great ideas flowing," Chip said. "From time to time, we need to challenge ourselves and our way and thinking. Instead of asking ‘why,’ we need to ask ‘why not?’"