How To Simplify the Pruning of High-Wire Tomato Crops

Chieri Kubota, Ph.D., Director of the Ohio Controlled Environment Agriculture Center (OHCEAC) at Ohio State University (OSU), is leading a study that aims to make growing high-wire tomato crops less labor-intensive.

The study places light sensors at the base of the tomato plants, which measure how much light is penetrating the canopy of leaves above. If the light measurements dip to a certain threshold (30-40 micromoles per square meter per second for this study), it suggests that lower leaves on the plant aren’t getting enough light to be productive—and can therefore be pruned.

“Conventional growers usually prune on a weekly or biweekly basis,” Dr. Kubota says. “It’s a very consistent interval when they send workers out to remove lower leaves.” By allowing the light levels to dictate pruning schedules on an as-needed basis, she explains, growers can potentially reduce labor hours.

The sensors can be integrated into an advanced greenhouse control tool; OHCEAC is using Koidra’s artificial intelligence (AI) system, which sends growers an email or text message when it’s time to prune.

“With this approach, growers can go without pruning for days or even weeks,” she says. “The time to prune is determined by how much light the plants are getting.”

Two postdoctoral research fellows have contributed to the research, along with several undergraduate students who work on the1,000-plus high-wire tomato plants in OHCEAC’s greenhouses.

“This experiment would be very hard to do on a small scale because the light isn’t always coming from the top of the plants. It comes at an angle, too, depending on the time of day,” Dr. Kubota says. “You have to have a certain size for this kind of research.”

This article is a part of CEAg World’s Industry Report: Greenhouse Produce. Download the full report here.