Bestsy Beers presenting at the 2018 WSTFA annual meeting

Betsy Beers, a Washington State University entomologist, discusses the rise of invasive pests threatening the state’s fruit industry, on Wednesday, Dec. 5, 2018, at the Washington State Tree Fruit Association annual meeting in Yakima, Washington. (Ross Courtney/Good Fruit Grower)

Two presentations by Betsy Beers, a Washington State University entomologist, highlighted Wednesday morning’s disease and pest management session on the third and final day of the Washington State Tree Fruit Association annual meeting.

Beers discussed the rise of invasive pests in the past 10 years or so, calling the trend “The New Normal” in her presentation title. Brown Marmorated Stink Bug, Spotted Wing Drosophila and Apple Clear Wing moth are just a few recent arrivals.

“Invasive species kind of took over my life and my lab in 2010,” she said.

Beers also discussed her three-year project testing the effectiveness of releasing sterilized codling moths by drone, in the hope that they breed themselves into submission. A video of the drone releases, set to Star Wars music, was a crowd pleaser.

A province-wide compulsory program releasing the sterilized pests by ATV in British Columbia, Canada, has led to drastic reduction, if not quite eradication. Beers aims to determine if Washington would get similar results with a patchwork and voluntary model. Her early results point to yes.

“Overall, very encouraging results for the first year of this project,” she said. She has two more years of trials coming up.

Another crowd pleaser was super close video footage of nematodes attacking, entering and feeding on codling moth larvae, from Diana Londono of the BASF Corporation. The company produces, sells and ships packaged nematodes. Growers just add water and apply with a sprayer, usually to trunks and soil.

New features of WSU’s online decision aid system, a grower panel on implementing pest and disease control methods and pear psylla research were among the other topics in the session.

Vigor management

In Wednesday morning’s other session, on vigor management, two grower panels focused on using water as a tool to control vigor and on the pitfalls of picking the wrong rootstock for a given planting.

Researchers often advise that picking the right rootstock at planting can save a lot of management headaches later, in terms of fighting too much or too little vigor. But that’s easier said than done, said Dave Allan of Allan Bros. Inc. and Mario Martinez of Washington Fruit and Produce Co.

“When I put together rootstock plans for a site, I feel like I am playing the lottery,” Martinez said.

While they shared stories of some bad combinations, the conversation quickly moved to how to avoid mistakes.

Understanding the soil you are going to plant on and accounting for the site variation by using different rootstocks in weak or strong areas, or training multiple leaders to split vigor in heavier soils can set the block up for success, the panel said.

Rootstocks are commonly discussed as a tool to control vigor, along with pruning choices, training systems, and use of plant growth regulators, but irrigation is also a very valuable tool that’s not to be overlooked.

“I think there is a lot of opportunity in using water to affect growth and cropping, but it’s a dangerous tool. You can make a mess with it, as anybody knows,” said panel moderator Mike Robinson of Double Diamond Fruit.

Growers on the panel discussed using strategic deficit irrigation to reduce vigorous growth associated with bitter pit development in Honeycrisp and fielded questions from the audience on soil moisture sensors and watering strategies. It’s the kind of strategy you need to carefully test out in your own block, however, and watch for signs of water stress that could tank fruit quality.

“I think 85 percent of what we do is water, so it’s important to get it right. Playing around with water has made me a better farmer,” said Chris Peters of Valley Fruit Orchards.

-by Ross Courtney and Kate Prengaman