WEED IPM ALTERNATIVES TO ATRAZINE IN SWEET CORN

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SPECIAL GRANT
• Reporting Frequency: Annual
• Accession No.: 0230991
• Grant No.: 2012-34381-20211
• Cumulative Award Amt.: $199,928.00
• Proposal No.: 2012-03266
• Project Start Date: Sep 1, 2012
• Project End Date: Aug 31, 2015
• Grant Year: 2012
• Program Code: [MX]- Pest Management Alternatives

Recipient Organization
AGRICULTURAL RESEARCH SERVICE
1815 N University
Peoria,IL 61604

Performing Department
(N/A)

Non Technical Summary
Sweet corn is one of the most popular vegetable crops in North America. Globally, the U.S. dominates production of sweet corn and sweet corn seed. Weed interference is a major, ongoing pest problem in sweet corn and a diverse community of weeds persists until harvest in most fields. Recent field surveys revealed that 57% of fields suffered yield loss due to weed interference, with 11% of fields subjected to losses averaging $135/ha. These losses occur despite growers' spending $123/ha on average on weed management. The main reason weed management costs are not even higher than present is because of heavy reliance on atrazine, an inexpensive broad-spectrum herbicide that controls a number of weeds that threaten production of all types of corn. Although atrazine has been an important herbicide to corn production for over 50 years in North America, its utility is drawing to an end. We propose to test different weed IPM alternatives utilizing combinations of competitive cultivars, mechanical weed control, alternative herbicide modes of action, and multiple application timings of mechanical and chemical tactics, and compare to standard, single- or double-pass atrazine-containing approaches. Experiments will be conducted for two years in each state, located within the primary production areas of sweet corn grown for processing. Therefore, results will be applicable to the key agronomic issues of each production area (e.g. dominant weeds, soils types, crop rotations). Results of an economic analysis will enable both growers and processors to see how their gross profit margins of standard and weed IPM alternatives to atrazine compare. Industry-identified commercial processing hybrids will be scored for relative competitive ability in additional field research. These data will be used to rank hybrids for their relative ability to tolerate competition. Growers and processors will then have a benchmark for predicting how the weed IPM alternatives they wish to adopt could perform using other industry-identified hybrids which they might choose to utilize. The distribution of weed IPM alternatives experiments is also a part of our technology transfer plan, serving as demonstration trials and enabling end users to learn about the project at their location and see results that are applicable to their respective production systems. Cumulatively, the involvement of stakeholders early in the development of this project, presentation of the work at field day events and winter meetings, publication of research results in a variety of formats, and engagement with the vegetable processing industry, we expect to influence weed management decisions made for nearly all of the sweet corn grown for processing in the Midwest.

Animal Health Component

70%

Research Effort Categories

Basic

(N/A)

Applied

70%

Developmental

30%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
216	1480	1140	100%

Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
1480 - Sweetcorn;

Field Of Science
1140 - Weed science;

Keywords

sweet corn

atrazine

weed management

weed interference

yield loss

crop competitiveness

stress tolerance

herbicide resistance

vegetable production

regulatory

Goals / Objectives
The goal of this work is to reduce growers' reliance on atrazine for weed management in sweet corn by identifying and demonstrating the most viable alternatives to atrazine. Objective and Sub-objectives: Demonstrate effective, economically viable weed IPM alternatives to atrazine. a. Test and compare weed IPM alternatives that integrate competitive cultivars, mechanical weed control, and judicious use of modern herbicides. b. Conduct an economic analysis of current atrazine-containing standards versus weed IPM alternatives to atrazine. c. Rank commercial hybrids for their relative competitive ability. Field experiments will be conducted in the primary production regions where sweet corn is grown for processing. These multiple sites will be representative of the unique weed issues and crop production practices of each area, and enable local stakeholders to see results of the project in the context of their respective production systems. In addition, project results will be presented at the MWFPA's Processing Crops Conference and at multiple field days. Publications in both the peer-reviewed literature and public media will increase distribution of the knowledge gained from the project.

Project Methods
We propose to test different weed IPM alternatives utilizing combinations of competitive cultivars, mechanical weed control, alternative herbicide modes of action, and multiple application timings of mechanical and chemical tactics, and compare to standard, single- or double-pass atrazine-containing approaches. Experiments will be conducted for two years in each state, located within the primary production areas of sweet corn grown for processing. Therefore, results will be applicable to the key agronomic issues of each production area (e.g. dominant weeds, soils types, crop rotations). Results of an economic analysis will enable both growers and processors to see how their gross profit margins of standard and weed IPM alternatives to atrazine compare. While only two commercial hybrids can best tested in the field trials of weed IPM alternatives, other major, industry-identified commercial processing hybrids will be scored for relative competitive ability in additional field research. These data will be used to rank hybrids for their relative ability to tolerate competition.

Progress 09/01/12 to 08/31/15

Outputs
Target Audience:Target audience of this project includes sweet corn growers and the vegetable processing industry, including company directors, field superintendents, and field supervisors. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project resulted in the training ofone agricultural sciences technician (GS-8), two graduate research assistants, and two undergraduates students in several facets of crop sciences, including field experimental design, multi-location study, horticulture, and weed science. In addition, one visiting PhDscientist (Arslan) used this project to hone her skills in English, scientific writing, and public speaking. How have the results been disseminated to communities of interest?Tworesearch presentations were made in 2015; oneat the University of Illinois and another atthe Weed Science Society of America meetings. One peer-reviewed manuscript was published, and a second manuscript is currently under internal reveiw. Results have been disseminatedwith oral presentationsat the International Sweet Corn Development Association meetings, Weed Science Society of America meetings, Pacific Northwest Vegetable Association meetings, and Central IllinoisIrrigated Growers Association meetings. A final presentation to stakeholders is planned in December 2015 at the Midwest Food Processors Association meetings. . What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The PI led a team of faculty and industry researchers, located throughout major processing sweet corn production regions, to identify viable alternatives to atrazine in sweet corn. Specific preemergence and postemergence herbicides, timely use of interrow cultivation, and adoption of competitive cultivars enables growers to eliminate the use of atrazine in sweet corn production without compromising weed control, crop yield, or profit. The U.S. not only leads global production of sweet corn, with a farmgate value >$1.1 billion, but also develops high-quality germplasm for much of the world.This research proactively involved the U.S. sweet corn industry in developing a contingency plan as ability to use atrazine declines. The team's efforts are being adopted by the processing sweet corn industry, safe-guarding production of America's most popular vegetable.

Publications

• Type: Journal Articles Status: Other Year Published: 2016 Citation: Arslan, Z.F., M.M. Williams II, R. Becker, V.A. Fritz, R.E. Peachey, and T.L. Rabaey. Weed management systems without atrazine in North American processing sweet corn. Prepared for submission to Field Crops Research (under internal review).
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Arslan, Z.F., R. Becker, V.A. Fritz, R.E. Peachey, T.L. Rabaey, and M.M. Williams II. Performance of weed management systems without atrazine in North American processing sweet corn. WSSA Abstracts. Available online:http://wssaabstracts.com/public/30/abstract-129.html
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Williams, M.M. II. 2015. Identifying crowding stress-tolerant hybrids in processing sweet corn. Agron. J. 107:1782-1788.?

Progress 09/01/13 to 08/31/14

Outputs
Target Audience: Target audience of this project includes sweet corn growers andthe vegetable processing industry, including company directors, field superintendents, and field supervisors. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Through hard-copy reports and oral presentations, preliminary results have been disseminated to sweet corn growers, vegetable processors, seed industry, herbicide manufacturers, and weed scientists. What do you plan to do during the next reporting period to accomplish the goals? Field experiments will be completed at the end of the 2014 growing season. Crop performance and weed data will be compiled across all site years, verified, and analyzed. Findings and conclusions will be drawn from the completed analysis, and specific weed management recommendations will be developed. Research presentations will be made to the Midwest Food Processors Association, International Sweet Corn Development Association, the Weed Science Society of America, as well asa university field day event. A manuscript will be prepared and submitted to Weed Science.

Impacts
What was accomplished under these goals? Since the project is not complete and experiments continue, the full impact of this project has yet to be realized. Currently, year 1 experiments have been completed. Since the goal of the project is to reduce reliance on atrazine for weed management in sweet corn, experiments must be conducted in a range of growing environments. Field experiments in 2013 were conducted at seven sites in 4 states, including Illinois, Minnesota, Wisconsin, and Oregon. These locations were chosen because they represent the diversity in weed populations and cropping practices where the majority of the nation's sweet corn is grown for processing. Preliminary results indicate that many of the weed management system alternatives to atrazine may not perform as well as systems that include atrazine. Specifically, weed control 14 days after treatment was >10% poorer compared to standard atrazine-containing systems. Single-year yield data suggest sweet corn was able to tolerate, to a certain degree, the additional interference; however, accounting forthe long-term cost of seed production from escaped plants is necessary. Field experiments for 2014 are underway. Once complete, these data will enable us to fully evaluate weed management systems in processing sweet cornanddetermine recommendations for the sweet corn industry. We anticipate the knowledge gained from this project will be critical in maintaining sweet corn production inareas subject to further restrictions on atrazine use.

Publications

• Type: Other Status: Other Year Published: 2013 Citation: Williams, M.M. II. 2013. 2013 report to the International Sweet Corn Development Association. ISCDA Annual Meeting, Chicago, IL Dec. 9-10, 2013.

Progress 09/01/12 to 08/31/13

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? The research is heavily dependent on field trials, which have only recently been planted. As such, the project is in its initial stages. What do you plan to do during the next reporting period to accomplish the goals? Year 1 trials will be completed within the next two months. These preliminary results will be shared with the sweet corn industry, including a presenation at the Midwest Food Processors Association winter meeting.

Impacts
What was accomplished under these goals? Field trials are testing and comparing weed IPM alternatives to atrazine in sweet corn. Trials are being conducted in five locations, throughout Illinois, Minnesota, and Wisconsin. In addition, relative competitive ability of 24 processing sweet corn hybrids are being quantified at Urbana, IL. Trials are currently underway, and progressing as planned.

Publications