Spring application of winter rye grain for weed control in summer vegetables

2012 Annual Report for ONE12-171

Project Type: Partnership
Funds awarded in 2012: $14,973.00
Projected End Date: 12/31/2012
Region: Northeast
State: New York
Project Leader:
Judson Reid
Cornell Vegetable Program

Spring application of winter rye grain for weed control in summer vegetables


In 2012 the Cornell Vegetable Program was awarded a NESARE grant to evaluate a new use of cover crops, by sowing winter rye between plastic-mulched beds of tomatoes and onions on two cooperating farms. Both farms provided cultivation and herbicide treatments to enable us to compare weed control, yield and pest and disease impacts. Although we documented weed control comparable to herbicides or cultivation, we also came across some unanticipated challenges, which may have been specific to 2012’s abnormal growing season.

We worked with cooperating growers on two farms, one growing onions and the other tomatoes. After fitting the soil and laying plastic, but before transplanting, both farms sowed winter rye at 3 bushels per acre between plastic as well as establishing herbicide and cultivation plots. Conventional fertilization and drip irrigation was carried out per each grower’s standards. We then collected data on plant height, weed biomass, insects, disease and yield. A detailed version of our Materials and Methods is available on the Cornell Vegetable Program’s webpage <cvp.cce.cornell.edu>; more specifically at:


Our work was shared with close to 250 growers at 2 field meetings and 1 formal presentation to date. Articles were published in the Veg Edge Newsletter, as well as posted on the Cornell Vegetable Program webpage.

Objectives/Performance Targets

Objectives from original proposal with updates below each bullet

•One of the two cooperating farmers will share their experience with at least 30 other farmers and researchers at a field meeting in the summer of 2012.

Our cooperating onion farm hosted a twilight meeting on August 3, 2012 with over 40 growers observing the trial first-hand. On August 10, another farm hosted nearly 100 people who learned of the project’s results and observed smaller test plots.

• The project leader will complete at least 50 farm visits to interested vegetable farmers to share research findings.

Over 100 farm visits were made in support of the project by the project leader and team technicians in the growing season of 2012.

• Winter presentations at the statewide Empire Fruit and Vegetable Expo, Produce Auction Growers Meeting and others will share the findings with an additional 300 farmers

Sessions are scheduled for the 2013 Finger Lakes Produce Auction annual meeting, Catskill Regional Agriculture Conference, and Empire State Producers Expo. A December 4 meeting for the Mohawk Valley Produce Auction shared the project with 40 growers.

• A reader-friendly summary of the project’s findings will be printed in VegEdge, a newsletter of the Cornell Vegetable Program that reaches over 850 people in 28 NY counties as well as the states of MA, MI, NJ, and PA.

A grower-oriented article was published in VegEdge on June 30, 2012.

• A newspaper version of our story, with color photos, will be submitted for print to the Finger Lakes Times, Country Folks and Lancaster Farming in the winter of 2012-13.

To be completed in 2013.

• An article will be submitted to American Vegetable Grower, with photos and project highlights.

To be completed in 2013.

• Biweekly updates of the project’s progress, including pictures, from 2 cooperating farms will be posted to the Cornell Vegetable Program’s webpage, with social media leads from the program team’s Facebook and Twitter accounts.

A mid-season report was posted on June 30, however the webpage has not adopted social media feeds to date.

• A full Technical Report of the project will be posted to the CVP Webpage

Submitted for posting on December 10.

• A non-technical, farmer oriented summary will also be posted to the CVP webpage with yield, disease, EIQ and labor inputs.

Submitted for posting on December 10.

• A link to these results will be posted to the Cornell University Guidelines for Commercial Vegetable Production within the Weed Management, Tomato and Onion pages.

To be completed in 2013.


Two small-plot, on-farm trials were conducted in Penn Yan, NY on two different farms, one growing onions and one growing tomatoes. Both farms provided cultivation and herbicide treatments to enable us to compare weed control, yield and pest and disease impacts.

Plant height was recorded 4 times for onions and three times for tomatoes. Disease and insect pressure was recored for both throughout the season. Leaf samples were collected for foliar nutrient level analysis, twice for onions, thrice for tomatoes. Weeds were collected from 4 random 1 square foot sections of row middles per treatment, three times each for tomato and onion trials.

Onions were harvested on August 16. All bulbs in 10 feet of bed per block were pulled, topped to 1 inch necks, weighed and sized. Bulb size distribution included colossal (>4”), jumbo (3-4”), medium (2-3”), small (<2”), culls due to rot and culls due to undersize or other. Tomatoes were harvested as they matured from July 19 to Sept 25. All marketable fruit was counted and weighed in pounds.

Statistical differences among treatments was determined by General Analysis of Variance (ANOVA) with mean separation by an LSD test with a p < 0.05

Impacts and Contributions/Outcomes

Rye as an inter-row cover crop presented challenges in this project. The primary effect observed was loss of yield, as measured by fresh weight of product. In tomatoes we lost over 8.5 pounds of marketable fruit per plant, a value of nearly $13/plant, assuming an average price of $1.50/lb, compared to the herbicide treatment. In onions the loss was over 18 lbs per 10 linear feet of row when compared to cultivation, the highest yielding treatment.

What is causing this yield loss is not completely understood. Mid-summer rainfall at both farms was scarce, and thus water competition is a possibility. Nutrient competition is also possible, with nitrogen and potassium at times lower in the rye plots, although trends are not clear. Allelopathy from the rye has also been suggested, even though rye roots did not extend underneath the plastic mulch when examined. Pest pressure in the tomato crop did negatively affect yield as common armyworm and slug feeding lead to many unmarketable fruit. The armyworm infestation was a regional phenomenon at abnormally high levels in 2012

On a positive note, rye successfully reduced the environmental impact of vegetable farming in this study by reducing erosion and replacing herbicides. On the cooperating onion farm eliminating a single herbicide application reduces the field Environmental Impact Quotient (EIQ) by 33.9 points per acre. At our tomato farm the replacement of 4 herbicides resulted in an EIQ reduction of 90 points/acre.

Rye also provided very good weed control at both farms. At our onion site it performed as well or better than herbicides and cultivation until harvest. At our tomato site late season weed pressure increased in the rye plots. There was an unexpected disease in the rye, leaf rust, which may have diminished it’s weed control at the tomato site. Labor associated with managing rye vigor was minimal as both cooperators reported mowing 1 time mid-season.

The Cornell Vegetable Program is not yet promoting this system, but rather researching it. We hope to refine our methods to develop a system that will be ready for adoption at a later date. Although the weed control of winter rye is very promising, the yield loss, particularly as caused by pest feeding in tomatoes, prevents promotion of the system at this time. Given the unique pest population in 2012, and dry growing season, these may be less in future seasons. We hope to look at other living mulches such as wheat and barley in the coming years, to work out the yield loss. A detailed version of this report is available online at <cvp.cce.cornell.edu>. More specifically at the page:

The authors express their gratitude to the cooperating farmers and NE SARE for their support.


Kathryn Klotzbach

Program Aide
Cornell Vegetable Program
12690 Rte. 31
Albion, NY 14411
Office Phone: 5798426585