Plantings at Yakima Valley Orchards are irrigated with drip. Travis Allan checks on a Honeycrisp block planted in 2007 where overhead sprinklers are being installed for frost protection.
An increasing number of orchardists are using drip irrigation systems to get their new orchard blocks off to a good start.
Tom Auvil, research horticulturist with the Washington Tree Fruit Research Commission, said drip is becoming standard for newly planted orchards because it can be rolled out quickly, applies water uniformly, and can be used for fertigation. “I think it’s a tool people are going to use more and more,” he said.
The most critical part of planting a new orchard is to get water to the trees without delay, Auvil stressed. The larger the planting material and the higher the temperature, the more critical it is to apply water immediately after the trees are in the ground.
Dan Plath, orchard manager at Washington Fruit and Produce Company, Yakima, Washington, said he uses drip in new orchards because he feels he can grow a better tree. In the first few years, the tree roots haven’t yet spread out into the alley, so there is no need to broadcast the water over the entire orchard. As well as saving water, this cuts fertilizer costs because nutrients can be applied through fertigation rather than broadcast.
Plath finds that short, but frequent, irrigation sets promote tree growth. In the height of the summer, he might irrigate a young orchard for 3.5 hours a day, seven days a week. As well as applying water, he’s applying fertilizer, which results in a better tree, he said.
In most cases, Plath takes out the flexible drip tape and installs undertree microsprinklers after three years, which allows for frost control. An overhead sprinkler system is installed at planting. For red apple varieties, such as Fuji, Braeburn, or Honeycrisp, this will serve for cooling the fruit. The overhead sprinklers are also used to irrigate the cover crop, which is planted in the fall of the first year to keep down the dust.
Travis Allan at Yakima Valley Orchards uses drip as a permanent irrigation system and installs drip tube that lasts the life of the orchard. When the trees come into production, he installs an overhead sprinkler system for cooling and undertree sprinklers for frost protection, but continues to rely on drip for irrigation.
Allan said he believes that newly planted trees perform better with drip irrigation than with sprinklers, and with the system he uses he wants to keep the canopy small as the trees mature. He feels that drip irrigation helps limit the root zone and stops the trees from becoming too vigorous.
A drip system also helps conserve water, which is more of a consideration in areas where water supplies might be limited.
Roger Wilson, owner of Wilson Irrigation and Orchard Supplies in Yakima, said another advantage of drip irrigation is that the application rate is lower so more of the orchard can be covered at one time.
Wilson said some growers use the durable kind of drip tube for the first three years, then take it out to install sprinklers for irrigation and frost protection. They can reuse the tube in new blocks.
Most orchardists use minisprinklers, rather than microsprinklers, Wilson said, because the larger sprinklers have bigger nozzles that are less likely to get plugged.
Instead of installing two separate sprinkler systems for frost control and cooling, some growers use one system for both. The sprinkler heads are moved up the trellis for cooling and moved down for frost protection. Though installing just one system is less expensive initially, Wilson said a drawback is the high cost of labor for raising or lowering the sprinklers. It’s cheaper in the long run to have two systems.