Yields up - dust down for Stanislaus County almond grower

Yields up - dust down for Stanislaus County almond grower

Dirkse credits the effective and consistent removal of mummies which can provide a haven for over-wintering Navel orangeworm (NOW) larvae, and the control of protein-eating ants that chew on nuts on the ground awaiting pickup after shaking from the trees.

After starting this year’s harvest on Aug. 3 - nearly two weeks sooner than usual, Stanislaus County grower Chuck Dirkse expects to have all of his almonds out of the field by mid-September.

Nonpareil accounts for about a third of Dirkse’s 310-acre La Mancha Orchards almond operation, which is spread over two ranches near Denair, Calif. The pollinator varieties include Avalon, Carmel, Fritz, Monterey, and Wood Colony.

About half way through the harvest, Nonpareil field weights and truckload numbers suggests yield could be 10 percent higher than last year, he believes.

“It’s certainly a better crop weigh wise and since it’s cleaner we should get a little bit better turn-out,” Dirkse says. “The pollinator yields appear a little higher than the Nonpariels.”

Statewide, the USDA 2016 almond objective forecast, released in early July, predicted a 7.9 percent increase in the size of this year’s California crop, compared to 2015.

Assuming his typically low inedible losses of about one-half percent from insect or bird damage or gumming continue, the quality of his 2016 crop should also be high, he notes.

Dirkse credits the effective and consistent removal of mummies which can provide a haven for over-wintering Navel orangeworm (NOW) larvae, and the control of protein-eating ants that chew on nuts on the ground awaiting pickup after shaking from the trees.

“Shaking or poling the trees in the winter to remove the mummies is one of the best forms of Navel orangeworm control since it takes away their nursery and removes over-wintering worms,” Dirkse says.

He’s also improved NOW pest control by dividing his hull split spray into two separate applications. Now, he treats field borders where more sun exposure can cause hull split first before applying his insecticide to the rest of the orchard once the nuts reach hull split stage.

“Before I started doing this when pulling off nuts as I walked along the outside rows, I could find a considerable number of worms,” Dirkse says. “This year, after spraying the borders first I hardly found any worms.”

His main ant threat is the fire ant. The loose seal of Nonpareil shells are especially vulnerable to ant damage.

To reduce damage, Dirkse uses an ATV-mounted unit to broadcast insecticide-laced bait in the orchards at a rate of 1 to 1½ pounds per acre. He does this once in May and then three-to-four weeks prior to harvest. To reduce the chance of insecticide resistance, he changes product chemistries.

“These baits definitely make a difference,” Dirkse says.

“For the first few years after planting the orchard, I didn’t apply a bait and ant damage to the nuts ran as high as 2.5 percent.”

Since starting bait treatments, he says ant damage is just a fraction of that.

“Considering the relatively low cost, I can’t understand why any grower wouldn’t use ant bait.”

At one time, Dirkse used sonic blasts from a propane gun to frighten away crows, pests that would damage his crop by pecking at the still soft nuts. However, once the crows ignored the sounds, he scare off the flock with the sound of a shotgun which he fired as he drove down the tree rows, chasing the flock as it moves around the orchard.

“After four or five days of shotgun sounds, the crows tend to move on and stay away,” Dirkse says.

This year he made two changes in his harvesting operation to improve air quality. As a result, he’s sending a cleaner crop to his huller-sheller.

“I’ve probably cut the dust output by about a third,” he says.

The first changes were adjustments to the sweeper head so only the rubber fingers touched the ground while the metal tines remained above the soil surface. As a result, less dirt went through the harvester, resulting in cleaner loads of nuts.

In addition, Dirkse replaced his well-worn harvester with a new model.

“This latest-generation machine is designed to allow more dirt to drop rather than blow out when picking up the nuts,” he says. “Also, instead of the fan blowing on the ground, it’s been redesigned to blow in a more horizontal direction. There’s no big blast of air stirring up dust from the ground."

On the irrigation side, Dirkse participated in a pilot project in April to test a new online program designed to simplify irrigation decision making.

Released shortly afterwards by the Almond Board of California, the free program allows growers to schedule their irrigations in response to local growing conditions, including the weather, orchard and soil conditions, and the type and efficiency of the irrigation system.

It’s available through the California Almond Sustainability Program website at www.SustainableAlmondGrowing.org.

Dirkse noted, “A program I’ve developed over the years to determine how much to irrigate has worked well for me but it requires a lot of my time to set up each year and use. This new online calculator is much easier – it’s a nice tool.”

In addition to this new technology, Dirkse has his eye on another way to save time in irrigation management.

Up to now, he downloaded and entered data from soil moisture monitors into his computer irrigation management program by hand. However, he’s considering an update to an internet-based service that does this automatically.

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