This Blackberry System May Really Prove Useful for the Southeast Growers

The Southeast berry growers may not have a useful alternative trellis system to improve their blackberry production. The researchers compared the rotating cross-arm (RCA) trellis system with a standard T-trellis system. At the moment, it is mostly growers in colder climates who use RCA. However, some in the Southeast found that it can benefit them as well.  Extension Horticulture Crop Specialist Amanda McWhirt, a researcher from University of Arkansas System Division of Agriculture’s Fruit Research Station, is one of the people who are testing how RCA can help the region.

How it Works

Blackberry trellis of a RCA system provide an almost horizontal platform capable of rotating 180 degrees. It has a vertical post and a rotating cross-arm. Fumiomi Takeda at the ARS Appalachian Fruit Research Station in Kearneysville, WV is the one who designed it.

This Blackberry System May Really Prove Useful for the Southeast Growers

Blackberry canes are attached to the trellis. This allows the plants to receive proper rainfall and light. The primocanes grow horizontally, and are tipped when they reach the next plant. They produce lateral canes and are tied to wires on the long cross arms.

During winter, the rows can rotate, with the tips of the cross arms resting on the ground. In spring, new leaves and flowers grow upward. When the flowers open, the trellis is rotated vertically. The fruit only develops on one side, and can be positioned to protect it from direct sunlight. The system is commercially available, and is sold at different retailers.

About the Research Project

The team uses three Arkansas-developed blackberry cultivars and collect data on fruit yields, flavor, post-harvest quality, and pest and disease dangers. They also keep track of the hours needed to manage both the RCA and standard systems. Their goal is to see how blackberry cultivars perform in these two different trellising systems.

McWhirt says, “Ultimately, we hope to use this data on crop production and combine it with our logs of how many hours are spent managing the two different trellising systems to evaluate the economics of investing in a rotating trellis system.”

RCA Trellis System benefits

True data is not yet available, but McWhirt says they worked with growers who use RCA trellis system, and that they see some real potential for the South. Some growers experience increased yields.

This Blackberry System May Really Prove Useful for the Southeast Growers

Growers are primarily using the trellising system as a means to increase yields and make harvesting easier. There also is thinking that fruit quality can be improved by orienting the trellis so that berries are on the north side, where they are shaded and protected from high temperatures and direct sun. This means the picker also is in the shade.”

She also adds that the system is not that widely used in the Southeast, and she thinks that both large commercial growers and smaller pick-your-own operations could benefit from them.

“I find this interesting because these growers have very different marketing strategies and customers, but both seem to have found the trellising system to improve their production systems. The ease and speed of picking on the rotating trellis helps both growers who have paid labor and growers who are trying to create an enjoyable picking experience for their customers.”

The system also helps with both late-spring frosts and high heat, genuine problems in the Southeast. Furthermore, it prevents or reduces heat-related disorders on blackberry fruit.

“Ultimately, the thinking is that white and red drupelet disorders are the result of high temperatures and direct contact of sunlight with the berries. If we can remove or reduce these factors, this may lead to better fruit quality on the rotating trellising system,” says the expert.

The next part of the research is to look at differences in berry temperature throughout the day in both systems, to learn how much they differ when it comes to heat-related disorders and postharvest quality.