Establishing or replanting an orchard is a money-making opportunity. The most cost-effective system to establish does not necessarily generate the highest return on investment. The focus needs to be on producing the highest quality fruit—and therefore the highest returns—in your environment, says Tom Auvil, research horticulturist with the Washington Tree Fruit Research Commission.
Below, Auvil explains how to maximize the profit potential of a new planting:
Have an ongoing review of your orchard so you know which blocks or segments are poor performers economically and need to be replaced. Select the new variety based on an understanding of the market value trends.
Make sure the variety you choose will perform well in your site or make plans to mitigate it. For example, if it’s a hot site, do you have adequate water for cooling? Is the soil able to drain the water you apply?
Some growers add a soil amendment, such as manure or compost, before planting to increase the organic matter, but in many replant sites, organic matter is not the limiting factor. Thorough ripping of the soil reduces compaction and allows easier redistribution and incorporation of organic matter from the old drive rows into the old planting row weed strips, creating a more consistent soil structure.
With adequate irrigation, most nutrients should be available to the trees in relatively balanced proportions, but you should know the nutrient status of the soils and irrigation and/or cooling water, so you can correct deficiencies.
There are key differences among rootstocks. Trees on Malling 9 tend to be 25 to 35 percent more yield efficient than trees on semidwarfing rootstocks. They produce more apples per acre, and, generally, larger fruit. Some plantings on M.9 are achieving 50 to 70 bins per acre, compared with a statewide average yield of 30 to 35 bins.
Replant tolerance is a critical trait. M.26 is a poor-performing rootstock in replant, and Budagovsky 9 is inconsistent.
EMLA 9, Nic (RN) 29, and Pajam 2 are vigorous M.9 clones, often similar to M.26 in new orchard sites. In replant sites, they often produce larger trees than M.26. Some rootstocks are more vigorous, and continue to be vigorous at maturity. Trees on Mark tend to grow vigorously until they fruit, so the canopy can be established quickly, and then grow more slowly when cropping begins. Another trait of Mark is its high percentage of bud and graft take, which is invaluable when planting bench grafts or sleeping eyes.
There are four ways an orchard can be established:
• Plant rootstocks in place and bud with the scion in late summer of the first growing season.
• Use bench grafts. These are rootstocks dug in the winter and grafted with the scion before planting out in the spring.
• Use sleeping eyes. These are rootstocks grown for one year in a commercial nursery or the orchard’s nursery block. They are budded in the fall, dug in the winter, and planted in the orchard the following spring.
• Buy full-grown nursery trees, which are grown for one or two seasons before planting in the orchard.
Don’t risk a substantial amount of money on planting sleeping eyes or bench grafts until you know you can do it successfully. Intensive monitoring and management are required. Tree performance must be assessed weekly, and if growth is inadequate in relation to the temperatures, decisions to correct the problem should be made every week.
An advantage of using bench grafts or sleeping eyes is the much shorter time lag between selecting a variety and putting it in the ground. Another benefit is that a sleeping eye or bench graft doesn’t suffer transplant shock, as a finished tree does, and the grower can manage branching and direct all the growth into a useful new canopy. With a finished tree, you’re often locked into the number of branches, their position, and their size.
However, inexperience with sleeping eyes and bench grafts can lead to a 30 to 40 percent loss of the young trees and irregular vigor, which tremendously increases management costs until the grower is able to fill in the holes and get a uniform canopy.
Replanting an orchard is an opportunity to configure it to take advantage of new technology, such as remote monitoring and robotic harvesting. Growers with old-style orchards will not be able to capitalize on cost-saving technologies, and it will become increasingly expensive to retrofit such orchards.
In a replant situation, fumigation will pay dividends. Trials in Washington State show yields are consistently 15 to 20 percent higher in fumigated plots. For a $700 per acre investment, the grower has that yield advantage for the entire life of the planting, and possibly better fruit quality and size.
Vapam (metam sodium) can be applied through the sprinkler irrigation system with enough water to settle it into the soil. It can be applied immediately after harvest, before the old trees are removed. Overirrigation may reduce the effectiveness of the fumigant by driving it too deep into the soil profile.
Telone C-17 or Telone C-35 can be applied after the old trees, trellis, and irrigation system are gone, so that the soil can be ripped thoroughly and the fumigant shanked in.
Fumigation should not be delayed in the fall, because it will not work well if the temperature is below 42 degrees. If the orchard being removed is a late-maturing variety, fumigation might have to be done in the spring instead.
Both sleeping eyes and bench grafts can desiccate or be injured by frost if planted too early. If the sleeping eyes are breaking dormancy or if the bench grafts have a quarter- to half-inch green, they will thrive better than if they are planted while fully dormant.
Sleeping eyes and bench grafts are usually planted by hand into the ripped orchard soil. Typically, workers make a slit into the soil with a hand trowel, insert the planting material, and tamp it down. There is no need to dig planting holes as would be done for a finished tree.
Whatever the planting material, it’s important to avoid scion rooting. Make sure the bud unions are four inches above the ground. Be aware of the difference between grafted and budded trees. The critical distance is from soil level to where the first piece of scion tissue is. Take into account that the trees will settle after planting and watering. Do not compromise. Scion rooting can occur in the first year of planting and negatively affect the performance of the tree forever. Having a few exposed roots is better than having scion rooting.
Examine “lineout” trees very carefully prior to planting; a high percentage of these trees will already be scion rooted.
Drip irrigation will more uniformly deliver water and nutrients to the young trees than a sprinkler system, and this is particularly important with sleeping eyes or bench grafts, which have very small root systems. Many operations have sprinklers in addition to drip so they can use them for frost control, maintaining a healthy cover crop, and evaporative cooling.
One of the greatest paradigm shifts is the idea of selectively developing branches for your training systems and discouraging or removing unwanted growth or detrimental shoots while they are very small in order to maximize development of the new bearing surface. If those unwanted limbs are retained, they will grow large and increase the caliper of the desired structure. As the desired limbs gain caliper beyond three quarters of an inch, the crop will develop further out on the limb, reducing yield efficiency. The smaller the wood, the more yield efficient the tree will be.
The growth regulator Apogee (prohexadione calcium) is a powerful tool for limiting vegetative growth.