Driving tree performance
Del Feigal counts on a crop of at least 70 bins per acre in the fourth leaf.
At Auvil Fruit Company, trees are planted as bench grafts with the union 6 to 8 inches above the ground to avoid scion rooting. Soil is mounded around weak trees to encourage scion rooting.
When Del Feigal replants an orchard block, he leaves nothing to chance. His strategy is to drive tree performance, rather than accept fate.
Feigal, manager at Auvil Fruit Company in Vantage, Washington, aims to produce 80 bins of apples per acre from the fourth leaf on, and he knows precisely how to get there.
It starts with land preparation. In a block he replanted last spring, he fumigated with Vapam (metam sodium) immediately after the 2005 harvest, spraying on the fumigant and irrigating it in. He then removed the old trees and ripped the soil three to four times in different directions.
“I feel strongly about taking the organic matter in the drive rows and mixing it up so we don’t have rich organic matter in one spot and not in another,” he said last fall during a field day about orchard establishment presented by Washington State University Extension and the Washington Tree Fruit Research Commission.
In January 2006, he installed the bottom four wires and the top wire for the 13-foot, eight-wire V-trellis system. The materials for this trellis cost about $3,000, plus $800 to $1,200 for the labor, but trellis costs have been increasing with the price of steel.
The trees were Mark rootstocks bench grafted in February with Fuji as the scion. They were planted out by hand, since the trellis system was already installed, at a density of 2,400 per acre. The benchgrafts were planted with the bud union six to eight inches out of the ground to avoid scion rooting. If a tree is weak, Feigal later mounds up the soil to promote more vigorous growth.
The Mark rootstock has outperformed all other rootstocks for bench grafts planted in place at that location, Feigal said. It tends to do well in most soil types. Nursery trees on Mark will outgrow trees on Malling 9 and are more precocious, he said. When they come into production, trees on Mark produce a lot of fruit and do not bear biennially.
Feigal uses a drip irrigation system so that he can deliver water to the trees every day. He thinks drip applies water more uniformly than a sprinkler system, because in a high-density system the tree trunks often block the path of the sprinklers. Another advantage of drip is it allows him to deliver nutrients directly to the tree.
Each tree has two side limbs trained flat to each wire of the trellis, and he applies Promalin (gibberellic acid and benzyladenine) from a spray bottle to get the branches to grow at the right places on the leader. Extra branches are nipped off. So, each tree has exactly 16 branches, plus short fruiting spurs on the leader.
The branches are taped to the wires when they are just four to five inches long—as soon as that can be done without damaging or breaking them. Workers go through the orchard every other week to train the trees and tape down the branches. Most branches will be permanent for the life of the system.
Feigal considers the first two years of the planting to be the nursery phase. During that time, he removes the crop to make sure that the trees grow enough to fill the space.
In year three, the trees enter their productive phase and should produce 40 bins per acre that year. By the fourth leaf, they should be producing 70 to 80 bins per acre.
When mature, each branch will be allowed to bear just two apples, and two more apples will grow on the short fruiting units off the leader between the wires. That’s exactly the number of size-64 apples needed to produce 80 bins per acre for the rest of the life of the planting, Feigal calculates.
Feigal said he likes to have four or five fruiting units on a branch so that he can choose the best positions to grow the two apples. Blossom thinning is done by hand to optimize fruit size and return bloom.
To control vegetative growth, he makes two applications of Apogee (prohexadione calcium) each season, the first at the pink stage of bloom, and the second about two to three weeks later, after thinning. In Granny Smiths, he does not treat the tops, to allow more vigorous shoot growth that will protect the fruit from sunburn.
Discussing the economics of the system, Feigal said returns in the third leaf should at least cover the costs for that year. With 70 bins an acre in the fourth leaf, returns that year should repay some of the debt as well as the growing costs.
“By the sixth leaf, it’s paid off its debt, and hopefully, it’s the right variety and productive for another six years before you have to pull it out,” he said.