Issue link: http://read.dmtmag.com/i/40315
RUNDOWN ON run throughs E uropean apple and pear growers have typically planted knip trees in their high-density plantings, but a Dutch nurs- ery is producing a new type of tree called a "run through" specially designed for super spindle systems and fruiting walls. Knip trees are feathered trees produced in the nursery over two seasons. They are produced either from bench grafts or from summer-budded rootstocks that are held over in the nursery for a second year. During the winter after the first season, they are headed at between 20 and 28 inches. A single shoot is allowed to grow from the top bud, and any later- als are removed. The shoot tends to grow very vigorously and produces branches. When finished, a knip tree should have six to ten well-distributed branches, or feathers. The run-through trees produced by Verbeek Nurseries in Steenbergen, the Netherlands, start off the same way as knip trees, but instead of being headed during the winter, they are allowed to run through the second year. Strong growth is removed, resulting in a tall tree with many short generative branches that are ready to bear fruit, Henk Nooteboom explained to the International Fruit Tree Association group when they visited the company. While most Dutch growers plant trees three feet apart, some are starting to plant trees closer. Run throughs—or grow throughs (door groei), as they are named in Dutch—can be planted as close as two feet apart. This creates a hedge that can be mechanically pruned to reduce costs. Nooteboom said because the trees are not "knipped," they are less susceptible to canker, which is a concern for European growers—particularly the British—because of their relatively humid climate. —G. Warner "We're trying to prove that the Dutch intensive systems are going to yield substantially more than the traditional English system." Sainsbury's, one of the major grocery chains in the Henk Nooteboom explains the difference between knip trees and run through trees at Verbeek Nurseries in Holland. Run through trees are taller and have smaller feathers. United Kingdom, proposed the demonstration orchard because it would like to sell more U.K. fruit, Caspell said. The 12,500 tons of the pears produced annually in the United Kingdom make up only a small percentage of the total pears sold. This reliance on imports has led to concerns about the country's food security. The concept orchard, which was planted in 2009, includes four different growing systems. All the trees are Conference on the Quince C rootstock, which was devel- oped at East Malling, and are planted three feet apart with 11.5 feet between rows. Verdi is the pollinizer. Caspell said it is not a scientific study, and the block will be managed as a commercial orchard would be, with an emphasis on the bottom line. Production last year, in the second leaf, averaged 12 bins per acre for the whole block. This year, he expected to harvest 17 to 18 bins per acre, slightly less than he had hoped because of some frost damage. The systems are: English bush: This is similar to traditional English pear orchards, but with a closer spacing. The top trellis is seven feet high. The trees were root pruned on one side last spring using an angled blade. Last year, in the second leaf, this system outperformed the others. Run through: This is a taller version of the standard English system, using "run through" trees from Verbeek Nursery in Holland (see "Rundown on run through). Trees are trained to a five-wire trellis with the top wire at 10.5 feet and supported by individual bamboo poles. Quad V system: Each tree has four leaders, two trained to trellis wires on each side and supported with bamboo canes. This is the easiest to prune. All but the four branches are removed, and any branches on the leaders that grow to more than a third of the diameter of the leader are cut back to a stump to allow regrowth. The trellis is 10.5 feet tall. Double head:Each tree has just two leaders trained to a V trellis. Caspell said he thought this would be the better system. Though it might not be the most productive, it should be the easiest to manage, and it lends itself to mechanical pruning, which the quad V does not. All the trees and trellis wire came from the Netherlands and the concrete posts from Italy. Caspell said nursery trees with two or four leaders don't cost any more than central leader trees. Not easy Caspell said it won't be easy to convince the British growers who stopped growing pears because they weren't making money on them to give it another try. "It's going to take a lot to get them back into it," he said. English supermarkets, like Sainsbury's, want to sell English-grown fruit, but for many consumers, price is more important, he said. "They don't care if it's English or from Outer Mongolia, as long as it's cheap." Supermarkets might pay a premium of one or two pence a kilo for English fruit, he said, but the Dutch can produce better crops, and transport across the English Channel is not very expensive. The concept orchard is a joint project of Sainsbury's, the fruit marketer Chingford Fruit Limited, and East Malling Research. • 16 SEPTEMBER 2011 GOOD FRUIT GROWER www.goodfruit.com geraldine warner