Corvallis, Oregon, USA
October 2, 2026
Tubs of red, orange and yellow tomatoes lined the edge of a research plot as dozens of visitors gathered around them at Oregon State University’s Vegetable Research Farm, evidence of what the plants had produced without irrigation during the growing season.
Nearby, cosmos bloomed along a field row while melons, cucumbers, sorghum and other crops filled plots across the farm.
The annual event, presented by the Dry Farming Program in the OSU Center for Resilient Agriculture and Food Systems, highlighted research on tomatoes, drought stress, seed production and crops ranging from cucumber melons to cut flowers.
The productive-looking plants illustrated both the potential and complexity of dry farming, the focus of OSU’s Dry Farming Field Day. Researchers showed growers, gardeners and agricultural professionals how they are testing crops, varieties and production practices that rely on moisture stored in the soil rather than irrigation during Western Oregon’s dry summers.
The field day also highlighted the Water Resilience Toolkit, an online collection of resources for farmers and agricultural service providers preparing for changing water conditions.
The annual event, presented by the Dry Farming Program in the OSU Center for Resilient Agriculture and Food Systems, highlighted research on tomatoes, drought stress, seed production and crops ranging from cucumber melons to cut flowers.
But Matt Davis, a senior faculty research assistant in OSU’s Department of Horticulture in the College of Agricultural Sciences who leads the Dry Farming Program, cautioned visitors against assuming what they saw could simply be reproduced on any farm.
“There are a number of things that make this site in particular really great for dry farming,” Davis said.
Soil sets the stage
The Vegetable Research Farm sits on deep Chehalis silty clay loam, Davis said, a soil that can hold winter moisture and make it available to plants well into the dry season. That stored water is crucial because the dry farm plots receive no in-season irrigation.
OSU Extension’s guide, Dry Farming: Assessing Your Site’s Potential, helps growers evaluate whether their soil, climate and other site conditions are suitable for dry farming.
Weed control is just as important.
Davis said the OSU dry farming team uses shallow cultivation, sometimes called dust mulching, to break up surface crusting and control weeds before they can draw away scarce moisture.
Lucas Nebert, assistant professor of practice and OSU Extension Service organic seed and planting stock specialist, said the farm also terminates its overwintering cover crop as early as conditions allow.
“The longer you leave your cover crop in, the bigger the plants will get,” Nebert said. “The more moisture they will take in from the soil and from deeper layers.”
After mowing, Davis said, the field was chisel-plowed about 8 to 9 inches deep and worked with a power harrow. Growers can then use furrows, deeper transplant placement or a seed drill to put seeds and transplants closer to moisture below the dry surface.
That management helps explain the vigorous plants visitors saw growing without irrigation.
Tomatoes test tradeoffs
The tubs of harvested tomatoes offered an introduction to one of the field day’s main research efforts.
Davis is collaborating with researchers at the University of California, Santa Cruz, on a tomato variety trial linking yield and fruit quality with traits such as water-use efficiency and how conservatively plants use water.
For growers, he said, a good dry-farmed tomato needs strong flavor, adequate yield and marketable fruit with fewer defects such as blossom end rot, yellow shoulder and cracking.
Those traits also affect the economics. Dry-farmed tomatoes generally yield less than irrigated tomatoes, but the fruit can command a higher price.
“I think that dry farm tomatoes can be more profitable than irrigated tomatoes,” Davis said.
Whether they are depends on variety and whether growers can capture a price premium. Davis said about a $1-per-pound premium could make dry-farmed tomatoes more profitable despite lower yields.
More crops, more options
Farther along the tour, visitors walked through plots marked with signs identifying cucumber melons, melons from Turkey, sorghum and other trial crops.
Nebert highlighted Armenian cucumbers and other cucumber melons, syrup and grain sorghum, chayote and dry-farmed corn. Some melon material came from western Turkey, where a Mediterranean climate resembles Western Oregon’s pattern of wet winters and dry summers.
Cucumber melons illustrate why crop choice matters. Though eaten immature like cucumbers, they are botanically melons and tend to handle drought better, Nebert said. Conventional cucumbers also are more likely to become bitter under dry conditions.
Sorghum often looks better than corn under limited-water conditions, he said.
Much of Nebert’s current work focuses on another question: whether growers can obtain seed and planting stock suited to dry farming. Many varieties in the trials came through the U.S. Department of Agriculture germplasm system, and his broader goal is to preserve promising material and make it available locally.
Testing seed and flowers
Nebert also led visitors through trials focused on seed production.
As part of a collaborative Organic Seed Alliance project, farms and universities across the country are growing the same cultivars and comparing seed production under dry-farmed and irrigated conditions.
At OSU, the trial includes zucchini, direct-seeded and transplanted lettuce and transplanted tomatoes. Researchers are asking whether saving and selecting seed under dry conditions could help crops adapt over generations, while also looking for tradeoffs such as smaller seed or lower germination.
One of the day’s most colorful stops was a cut-flower trial, where pink and white cosmos bloomed densely as attendees gathered along the row.
The trial includes cosmos, strawflower, sunflower, zinnia and marigold. Researchers are comparing stem count and length to determine which crops and varieties might be practical for dry farming.
Different drought strategies
For Jim Myers, professor emeritus and retired vegetable breeder in the Department of Horticulture in the College of Agricultural Sciences, the question is why some tomatoes handle dry conditions better than others.
Myers summarized a trial grown in 2025 of 106 tomato varieties and lines, including modern and heirloom tomatoes as well as wild relatives.
The trial received about 2.4 inches of rain during the growing season, far less water than the plants lost through evaporation from the soil and water released through their leaves. Researchers took measurements in the field and used drones with special cameras to look for signs of plant stress.
The images helped researchers compare how green and vigorous the plants remained under dry conditions. They also measured the temperature of the plant canopy. Cooler plants can be a sign that they are still moving water through their leaves and experiencing less stress.
Some wild and ancestral tomato types stayed greener and cooler than others. Among cultivated varieties, ‘Large Pink’ and ‘Walter’ performed relatively well, Myers said, while ‘Taxi’ showed more signs of stress.
The plants may be using different strategies to cope with drought.
Myers suspects some large, bushy ancestral tomatoes develop deep roots that reach water farther below the surface. Other cultivated tomatoes stay smaller and put more of their energy into producing fruit.
“They grab what water they can,” Myers said. “They grow really fast. They put most of that photosynthate into fruit, not into vegetation.”
The trial also showed substantial differences in blossom end rot, even among processing tomatoes with similar shapes. Those differences could help breeders develop tomatoes that better combine drought tolerance, yield and fruit quality.
Preparing for less water
The field day made clear that dry farming is not simply a matter of turning off irrigation.
It depends on soil, crop choice, field management, planting methods, seed sources and genetics. What works in deep Chehalis silty clay loam at the Vegetable Research Farm may not translate directly to every farm, but the research is helping identify approaches growers can consider when water is limited.
For Davis, that means understanding how growers can produce high-quality crops with less irrigation. For Myers, it means identifying the plant traits and genetics that make that possible.
For Nebert, it also means thinking about the future of seed itself.
“Every time you’re saving seed, every time you’re making selections, that plant is adapting, is evolving,” Nebert said. “So, in principle, if we’re dry farming our seed, maybe we’re adapting it for climate change more readily.”
>> Photos
Topics
Species
