By Sarah Cato
U of A System Division of Agriculture
CLARKSVILLE, Ark. — Gov. Sarah Huckabee Sanders has proclaimed June as Arkansas Blackberry Month and the University of Arkansas System Division of Agriculture celebrated by hosting a field day to showcase its research and education efforts.
A MONTH OF BERRIES — Margaret Worthington, associate professor of horticulture for the U of A System Division of Agriculture, addresses attendees during the blackberry field day in Clarksville earlier in June. (Division of Agriculture photo.)
The 2023 Blackberry Field Day, hosted in partnership with the Arkansas Blackberry Growers Association at the Fruit Research Station, welcomed almost 90 blackberry growers from Arkansas, Missouri, Texas and Oklahoma. The research station is a part of the Arkansas Agricultural Experiment Station, the research arm of the Division of Agriculture.
The Division of Agriculture is world-renowned for its blackberry varieties, which are grown on every continent except Antarctica. In 2017, blackberry production in the U.S. was valued at $31.1 million, according to the Agricultural Marketing Resource Center.
The field day kicked off with indoor presentations on blackberry aromas and efforts to boost public interest in blackberries.
Promotion research
“We’ve partnered with the Arkansas Blackberry Growers Association to increase blackberry promotion in Arkansas,” said Lizzy Herrera, extension horticulture program associate for the Division of Agriculture. “We’ve created several promotional materials in an attempt to market blackberries as the healthy, fresh and local treat we know they are.”
With funding from the Specialty Crop Block Grant, administered by the Arkansas Department of Agriculture, Herrera said a survey was distributed last year to assess marketing habits, pricing, and what type of promotional materials growers would like to see. These answers were used to create recipe cards, stickers, road signs, and other promotional materials. Sales dollars for participating farms will be tracked over two years.
Increasing herbicide options
Matt Bertucci, assistant professor of horticulture for the Division of Agriculture, discussed his research on utilizing 2,4-D choline, a post-emergent broadleaf herbicide, in blackberry production. The chemical is not currently labeled for use in blackberries in Arkansas.
Pre-emergent herbicides, which target germinating seeds, are typically used to control broadleaf weed species. But pre-emergent herbicides can fail over time and are not effective on perennial broadleaf weed species.
“You may be wondering why we’d spray a broadleaf herbicide on a broadleaf crop,” Bertucci said. “Our goal is to apply enough chemical to kill the weed, but not enough to hurt our plants.”
Bertucci’s research aims to pin down that sweet spot of how much herbicide will effectively control broadleaf weed populations without lowering yield or fruit quality, and, hopefully, get the product labeled for use in Arkansas blackberries to give growers more options to control problematic broadleaf weed species. This research is funded by the IR-4 Project, an organization with a focus on developing data required by the U.S. Environmental Protection Agency for the registration of pest management tools for specialty crops.
Rotating Cross Arm Trellis
Amanda McWhirt, horticulture production specialist for the Division of Agriculture showed attendees the rotating cross arm trellis, or RCA, used in her current research trial looking at labor data, fruit quality, and canopy conditions compared to the traditional T-trellis. However, one major benefit to the RCA comes with the recent surge in early season freezes Arkansas fruit growers have suffered the past few years.
“We’ve had many growers implement the RCA on their operation with great success,” McWhirt said. “It creates a really attractive wall of blackberries that is great for U-Pick operations, and several have said it’s saved them from the freezes we’ve been dealing with the past several years.”
The RCA trellis allows growers to lay the plants down, closer to the ground. This, paired with a cover, keeps the buds warmer during early-season cold snaps, oftentimes saving them from significant cold damage. However, the RCA helps battle summer struggles as well.
With the RCA, plants produce fruit on one side of the trellis. During the summer, producers can rotate the trellis to keep the fruit in the shade and reduce sun exposure, which McWhirt said is a common cause of red drupe, white drupe, and sunscald. This practice also reduces temperature and lowers humidity within the canopy, making a less-favorable environment for spotted wing drosophila, a common pest of blackberries. But the environmental characteristics aren’t the only advantage when it comes to controlling spotted wing drosophila on an RCA.
“We have also seen increased coverage in our insecticide sprays targeting spotted wing on the RCA. It gives us a nice wall of berries and your sprayer will hit them dead on every time,” said Aaron Cato, horticulture IPM specialist for the Division of Agriculture. “Because of this, we think it is possible that the RCA requires less spray volume compared to our traditional T-trellis. It may not seem like much, but if you’re covering a ton of acres, reducing 10 to 20 gallons of water can save a lot of time.”
Cato said other cultural control options are a must as well. He suggests harvesting often, keeping fields clear of discarded or culled berries and moving harvested fruit into cold storage as soon as possible.
The field day had an extended tour that touched on the blackberry breeding program, summer tipping reminders, blackberry fertility, and more. Learn more about blackberry production in Arkansas at uaex.uada.edu.
To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on Twitter and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu/. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk.