The West Michigan Research Station has been operating for more than a year, and its research projects are starting to bear fruit. Michigan State University researchers held a tree fruit field day and pear meeting Nov. 1 to demonstrate what they’ve been up to.
The station, built in 2021, includes multiple buildings and 68 acres of farmland in Hart and is the home of several asparagus and tree fruit research projects. Funded by a partnership between MSU and a group of growers and processors in West-central Michigan, the facility was long on the wish list of the region’s growers, who wanted research specifically tailored to their soils and climate.
About those trellises …
MSU apple production specialist Anna Wallis talked about a new block of apples that’s testing alternative trellis materials. The block, Aztec Fuji on Geneva 11, spaced 2.5 feet by 10 feet, has rows with fiberglass and steel posts, testing how well they hold up in high-density orchards. Growers are looking for alternative post materials due to a shortage of pine posts, she said.
The jury is still out on the fiberglass posts, which are repurposed from the oil industry. The hollow posts are very flexible and might need to be filled with another material to be strong enough for an orchard trellis, Wallis said.
The fiberglass posts were difficult to work with, too. Installation crews had a hard time pounding them into the ground because of their tendency to bend. And to keep the wires connected to the posts, they had to drill holes in them, said John Bakker, the station’s interim orchard manager.
“I’ve done a lot of building,” Bakker said. “I’ve never drilled a material that wears out a drill bit faster than fiberglass.”
Bakker also recommended wearing gloves whenever handling fiberglass posts.
“I think the final fiberglass slivers just worked their way out of my system about a month ago,” he told the field day attendees. “They were annoying me all summer long.”
The steel posts, designed by TrellX in Washington state, perform exceptionally well in orchards but are expensive. They hope to test posts made of concrete and possibly other materials in the future, Wallis said.
“There’s some good alternatives here,” Bakker said. “But more work needs to be done.”
Other research news
MSU entomology professor John Wise discussed different biopesticide application methods to control pear psylla, a major pest. West-central Michigan is home to a significant portion of the state’s pear acreage, much of it sold to local processors.
In laboratory settings, biopesticides are often just as effective as conventional pesticides, but they tend to break down more rapidly in an outdoor orchard environment. Ideally, biopesticides should be delivered in a “way that optimizes their performance, as opposed to just throwing it up in the air and walking away,” Wise said.
Wise thinks trunk injection might be a more effective way to deliver biopesticides. He’s been studying trunk injection for more than a decade and started injecting pear trees at the research station in 2021, he said.
Trunk injection involves piercing a tree’s bark and applying chemicals directly into its vascular system. The technique was developed for the ornamental and forestry markets but doesn’t yet have a commercial application in tree fruit. While it’s a very effective biopesticide delivery method, the amount of time and labor involved in injecting each tree makes it a poor fit in commercial-scale orchards — at least right now, he said.
“How to make it work for tree fruit production is a really serious challenge that has to be addressed,” Wise said.
Emily Lavely, MSU tree fruit educator for West-central Michigan, discussed the station’s high-density Bartlett pear planting. The trees are trellised, trained to the tall spindle system, and planted on Amelanchier and quince rootstocks. In the coming years, as part of a long-term research project, they’ll evaluate the trees’ fruit set, scion and rootstock compatibility, fire blight resistance and other factors, she said.
MSU research assistant Cory Outwater gave an update on the station’s cherry leaf spot trials. Cherry leaf spot is a major problem in Michigan tart cherries, including in the West-central region. In separate blocks, researchers compared the performance of fungicides Bravo and Initiate (both chlorothalonil), and captan and Kocide (copper hydroxide). Kocide, which they sprayed at 4 pounds per acre instead of the label-recommended 3.5 pounds, was the only product that provided season-long protection. Spraying Kocide at the higher rate provided greater control, though phytotoxicity did lead to some defoliation, Outwater said.
“The important thing is we are holding onto the majority of the leaf,” he said. “So, it might look really ugly early on, but it is controlling the disease.”
Outwater plans to conduct the trials again this year and collect more data, he said.
—by Matt Milkovich