This article originally ran in the fall 2017 issue of New Farm Magazine, the magazine of Organic Farmers Association. All OFA members receive a complimentary issue of New Farm twice per year. Click here to sign up!
Farm Bulletins: Research You Can Use
edited by Scott Meyer
Inherited Weed Tolerance
Since 2015, scientists at Rodale Institute have been conducting research to ascertain whether crops can be bred to tolerate weeds. A recent study at the University of Wyoming found that weed tolerance can become an inherited trait in sugar beets. Now researchers at Rodale Institute, in collaboration with Andrew Kniss, Ph.D., an associate professor of plant sciences at the University of Wyoming, are assessing whether exposing wheat and oat plants to weed pressure can improve the ability of the next generation to adapt to the challenge.
When young plants receive less red-spectrum light as a result of being shaded by weeds, they exhibit a variety of responses that may allow them to better compete for the critical resource; among them are upright growth, reduced branching, an increase in the stem elongation rate, and changes in the tim- ing of seedhead emergence, says Emmanuel Omondi, Ph.D., research director for the Farming Systems Trial at Rodale Institute. “What we are trying to do in collaboration with Dr. Kniss is to determine if this response to ‘unwanted neighbors’ can be inherited and if the progeny performance can be superior to parental performance,” Omondi says. That is, can the second generation be already adapted to expected “unwanted neighbors,” and respond more strongly to those neigh- bors than the first generation did, without having to sacrifice yield potential.
“Studies have confirmed that progeny of plants exposed to pathogens responded more strongly against those pathogens than their parents did,” Omondi adds. “We are hoping to show the same response with weeds.”
Kniss collected and analyzed data on second-generation wheat exposed to weeds. “The data strongly suggest that the heading date in second-generation wheat was influenced more by the previous generation’s growing environment than the current grow- ing environment,” Omondi reports.
Cover Crop Disease Control
Research has shown that hairy vetch (Vicia villosa) can not only suppress soilborne diseases of cucurbit crops when it’s incorporated as a green manure but also inhibit foliar diseases when residue remains on the soil surface for no-till vegetable production, according to Andrew Smith, Ph.D., research director of the Vegetable Systems Trial at Rodale Institute. He’s now conducting a study that is “evaluating hairy vetch as part of an integrated strategy intended to reduce disease and disease-management costs and increase cucurbit production and farm income.”
METHOD Vegetable growers at Blooming Glen Farm in Perkasie, Pennsylvania, are collaborating on this project with Rodale Institute researchers. Plots of winter squash at each site have been planted with a cover crop of hairy vetch. Rodale Institute is com- paring two conventional and two organic management strategies, while Blooming Glen is testing only the organic systems.
• Organic no-till (at both sites): The cover crop is terminated in the spring with a roller-crimper.
• Organic tilled, with plastic mulch (at both sites): The cover crop is terminated in the spring using a flail mower, tilled
in with a moldboard plow and a single pass of the disc, and covered with black plastic mulch.
• Conventional no-till (at Rodale Institute only): The cover crop is terminated in the spring with herbicide sprays and rolled down using a packer.
• Conventional tilled, with plastic mulch (at Rodale Institute only): The cover crop is terminated in the spring using a flail mower, tilled in with a moldboard plow and a single pass of the disc, and covered with black plastic mulch.
The study will also compare the use of organic and conventional herbicides on powdery mildew.
RESULTS Researchers are hoping the two-year study will demonstrate the competitiveness of organic specialty crop production by reducing the use of nitro- gen fertilizer and chemical and mineral fungicides and increasing plants’ disease resistance.
Squash System Comparison
No-till, low-input technology has the potential to conserve soil health and support robust vegetable production for small-scale and low-capital organic vegetable growers, reports Gladis Zinati, Ph.D., associate research scientist at Rodale Institute. She is evaluating three management systems for growing winter squash in a demonstration trial at two farms. The preliminary results indicate that the no-till, low-input system can be cost effective, reduce labor, and increase long-term profitability and sustainability.
METHOD Research and demonstration trials have been established at two Kutztown, Pennsylvania, locations: Rodale Institute and Quiet Creek Farm. Three strategies are employed at the Rodale Institute site: The first is a low-input-technology system in which cover crops are rolled and crimped using a walk-behind BCS tractor with a 2-foot roller-crimper attachment. The second is a high- input-technology system where cover crops are rolled using a 10-foot roller-crimper mounted on a tractor. The third is a standard plastic-mulch system: Cover crops are plowed under, and the soil is covered with black plastic mulch. The test plots are arranged in a randomized complete block design with four replications. At the Quiet Creek Farm site, the first two strategies are being compared to a bare-ground system (Quiet Creek’s standard). ‘Waltham Butternut’ winter squash was planted at both sites.
RESULTS This project, supported by a Northeast SARE (Sus- tainable Agriculture Research and Education) Partnership Grant, will generate data that can guide small-scale organic farmers seeking viable low-input options for using a no-till system to raise vegetable crops. Final results will be tabu- lated in winter 2018 and made public in spring 2018.