Reducing the Risks Associated with Herbicides for Growing Pumpkins in New England

Frank J. Himmelstein, Ph.D.
University of Connecticut
24 Hyde Avenue
Vernon, CT 06066
860-870-6932
860-875-0220 (fax)
fhimmels@canr.cag.uconn.edu

Executive Summary

Programs that address the weed management needs for farmers growing pumpkins in New England are desperately needed. Thousands of acres of pumpkins are grown in New England. In Connecticut alone, we have estimates that several thousand acres of pumpkins are grown. Our weed management programs in Connecticut have already helped growers throughout New England reduce the negative impact of weeds associated with growing field and sweet corn. Growers in our state have obtained knowledge primarily through field-scale applied research plots located at the University and from on-farm demonstration plots conducted throughout the State. However, education is delivered to growers throughout the New England region at grower meetings and through extension publications. The success of our programs have produced positive impacts in field and sweet corn yield and quality and play a significant role in maintaining environmental quality in the region. We would now like to take our experience with these crops and apply it to assist growers with weed management concerns in pumpkins.

Two of the major herbicides used in pumpkins, clomazone and ethalfluralin, have either the potential to injure the crop being grown or cause severe injury to non-target plants. Clomazone is sold under the trade name Command. Drift from applications of clomazone can cause severe injury to adjacent plants. Due to the likelihood of injury to non-target plants, the label recommends that this herbicide should not be applied within 1,000 feet of towns and housing developments, commercial fruit or vegetable production, and commercial greenhouses or nurseries. Ethalfluralin is sold under the trade name Curbit. Control of weeds is inconsistent with this material and use of this herbicide during cold, wet weather can result in crop injury or stunting. These pesticides are toxic to fish and aquatic invertebrates. Runoff or erosion from treated areas may be hazardous to fish in neighboring areas.

Research that eliminates or reduces the use of these herbicides on pumpkins are needed. A rye cover crop is commonly used in vegetable production to reduce soil erosion, take up excess nutrients, and add organic matter to the soil. Rye is also known to release allelopathic chemicals that are harmful to many weeds as it decays. The first goal of our proposed project is to determine the best way to manage a rye cover crop as a potential weed management option in pumpkins. The rye cover in our study will either be mowed, rolled, or killed with glyphosate prior to seeding pumpkins in a narrow tilled band in the field. Weed control will be assessed and crop yields determined. The second goal of our proposed project is to examine other herbicide alternatives that could be used in pumpkins that are not as hazardous to the environment as the currently labeled materials. The studies will be conducted at the Plant Science Research and Teaching Facility in Storrs, CT and at commercial pumpkin grower's fields. Plot tours, grower meetings, and extension facts sheets will be used to educate pumpkin growers how to reduce those herbicides in pumpkins with the potential to have negative impacts on the environment as well as non-target plants. Grower surveys will be conducted to determine if growers would be willing to change practices should our research results prove to be an effective alternative to the current commercial standards. This project will allow the necessary research, education, and outreach activities to reduce the environmental risks from herbicide use in pumpkins.

Objectives

The three major objectives of this grant proposal are:

To develop new alternative weed management programs for pumpkins that reduce the use of high risk herbicides in terms of environmental impact.
To conduct local and regional educational programs each year for growers, consultants, extension educators and industry representatives.
To deliver new weed control fact sheets for pumpkins and revise regional extension educational materials.

Justification

Programs that address the weed management needs for farmers growing pumpkins in New England are desperately needed. Thousands of acres of pumpkins are grown in New England. In Connecticut alone, we have estimates that several thousand acres of pumpkins are grown. Two of the major herbicides used in pumpkins have either the potential to injure the crop being grown or cause severe injury to non-target plants. These pesticides are also toxic to fish and aquatic invertebrates. Runoff or erosion from treated areas may be hazardous to fish in neighboring areas. Our weed management programs in Connecticut have already helped growers throughout New England reduce the negative impact of weeds associated with growing field and sweet corn. Growers in our state have obtained knowledge primarily through field-scale applied research plots located at the University and from on-farm demonstration plots conducted throughout the State. Education is delivered to growers throughout the New England region at grower meetings and through extension publications. The success of our programs have produced positive impacts in field and sweet corn yield and quality and play a significant role in maintaining environmental quality in the region. We would now like to take our experience with these crops and use it to assist growers with weed management concerns in pumpkins.

Overall Summary

Programs that address the weed management needs for farmers growing pumpkins in New England are desperately needed. Thousands of acres of pumpkins are grown in New England. It is difficult to determine the exact acreage since there are many small growers in the region. In Connecticut alone, we have estimates that several thousand acres of pumpkins are grown. Our weed management programs in Connecticut have already helped growers throughout New England reduce the negative impact of weeds associated with growing field and sweet corn. Growers in our state have obtained knowledge primarily through field-scale applied research plots located at the University and from on-farm demonstration plots conducted throughout the State. However, education is delivered to growers throughout the New England region at grower meetings and through extension publications. The success of our programs have produced positive impacts in field and sweet corn yield and quality and play a significant role in maintaining environmental quality in the region. We would now like to take our experience with these crops and use it to assist growers with weed management concerns in pumpkins.

Two of the major herbicides used in pumpkins have either the potential to injure the crop being grown or cause severe injury to non-target plants. Clomazone sold under the trade name Command is a commonly used herbicide in pumpkins. Drift from applications of clomazone can cause severe injury to adjacent plants. Since this herbicide is a bleacher, injury symptoms of foliar whitening or yellowing may occur on non-target plants. Due to the likelihood of injury to non-target plants, the label recommends that this herbicide should not be applied within 1,000 feet of towns and housing developments, commercial fruit or vegetable production, and commercial greenhouses or nurseries. Ethalfluralin sold under the trade name Curbit is another herbicide that is commonly used in pumpkins. Control of weeds is not consistent with this material unless rainfall occurs within five days of application. Use of this herbicide during cold, wet weather can result in crop injury or stunting. Currently a mixture of these two herbicides is being sold under the trade name of Strategy. These pesticides are toxic to fish and aquatic invertebrates. Runoff or erosion from treated areas may be hazardous to fish in neighboring areas.

Research that eliminates or reduces the use the these herbicides on pumpkins are needed. Projects for pumpkins will be developed to evaluate new weed management alternatives that should result in either the elimination or the reduction in use of these pumpkin herbicides with high risk in terms of environmental impact. A rye cover crop is commonly used in vegetable production to reduce soil erosion, take up excess nutrients, and add organic matter to the soil. Rye is also known to release allelopathic chemicals that are harmful to many weeds as it decays (Barnes and Putnam, 1983). The first research goal of our proposed project is to determine the best way to manage a rye cover crop as a potential weed management option in pumpkins. The rye cover in our study will either be mowed, rolled, or killed with glyphosate prior to seeding pumpkins in a narrow tilled band in the field. The second research goal of our proposed project is to examine other herbicide alternatives that could be used in pumpkins that are not as hazardous to the environment as the currently labeled materials. Weed control will be assessed and crop yields determined in both studies. The studies will be conducted at the Plant Science Research and Teaching Facility in Storrs, CT during year one and two and at a commercial pumpkin grower's field in year two. Plot tours, grower meetings, and extension facts sheets will be used to educate pumpkin growers, consultants, educators, and industry representatives how to reduce those herbicides in pumpkins with the potential to have negative impacts on the environment as well as non-target plants. Grower surveys will be conducted to determine if growers would be willing to change practices should our research results prove to be an effective alternative to the current commercial standards. Contamination from pesticides used in agricultural production is of great concern to residents throughout New England where agricultural and suburban areas are situated in close proximity to one another. The effect of pesticides on the environment will continue to be a major public issue. Alternative weed management practices which reduce the use of herbicides with possible severe impacts to the environment will reduce the potential for future contamination. IPM strategies that can provide growers with effective weed control yet reduce the amount of herbicides required to provide this control are needed. The outcome of this project will provide the basis for improved regional weed control recommendations that improves agricultural viability and protects natural resources.

Approach and Outcomes

The purpose of this grant request is to conduct research projects that will enable growers to manage weeds in pumpkins in an economical and environmentally sound manner. This project will develop and demonstrate alternative weed management programs that will reduce the use of high risk herbicides in pumpkins. Information will be delivered through plot tours, grower meetings, and extension fact sheets and publications.

Projects for pumpkins will be developed to evaluate new weed management alternatives that should result in either the elimination or the reduction in use of these pumpkin herbicides with high risk in terms of environmental impact. A rye cover crop is commonly used in vegetable production to reduce soil erosion, take up excess nutrients, and add organic matter to the soil. Rye is also known to release allelopathic chemicals that are harmful to many weeds as it decays. The first research goal of our proposed project is to determine the best way to manage a rye cover crop as a potential weed management option in pumpkins. The rye cover in our study will either be mowed, rolled, or killed with glyphosate prior to seeding pumpkins in a narrow tilled band in the field. The second research goal of our proposed project is to examine other herbicide alternatives that could be used in pumpkins that are not as hazardous to the environment as the currently labeled materials. Weed control will be assessed and crop yields determined in both studies. These studies will be conducted in 2003 and 2004. The studies will be conducted at the Plant Science Research and Teaching Facility in Storrs, CT during year one and two and at a commercial pumpkin grower's field in year two. Plot tours, grower meetings, and extension facts sheets will be used to educate pumpkin growers, consultants, educators, and industry representatives how to reduce those herbicides in pumpkins with the potential to have negative impacts on the environment as well as non-target plants.

Impact Assessment

The impact of the project on participating clientele will be measured by surveys. Grower surveys will be conducted to determine if growers would be willing to change practices should our research results prove to be an effective alternative to the current commercial standards. Participants at grower meetings will complete questionnaires to help determine the success and effectiveness of the program. Participant satisfaction with knowledge gained and effectiveness of new weed control alternatives will be assessed.

Literature Cited

Barnes, J.P., and A.R. Putnam. 1983. Rye Residues contribute weed suppression in no-tillage cropping systems. J. Chem. Ecol. 9:1045-1057.

Timetable

Demonstration and Research Sites
-site setup	May /June 2003 May /June 2004
-tours	Aug/Sept 2003 Aug/Sept 2004
Publications
-materials for producers	Nov/Dec 2002 Apr/Aug 2003 Nov/Dec 2003 Apr/Aug 2004
-trade journal articles	Apr 2003 Apr 2004
Grower Meetings	Nov/Dec 2002 Apr/Aug 2003 Nov/Dec 2003 Apr/Aug 2004
Program Evaluations
-pre program evaluation	Dec 2002
-post program evaluation	Nov 2004
Accomplishment Reports
-quarterly reports-as requested -final report-as requested

The studies will be conducted at both the University and grower sites as detailed. A tour will be conducted each year to the project sites. Fact sheets/extension publications will be written each year. Talks will be presented at local and regional meetings for growers each year.

Major Participants

Dr. Frank J. Himmelstein- Project Coordinator, University of Connecticut

Dr. Himmelstein will coordinate the research and extension efforts of the project. Dr. Himmelstein has been involved in weed control projects in field and forage crops for more than twenty years. For the last eleven years as an Extension Educator in the Cooperative Extension System of the University of Connecticut. he has developed, implemented, and evaluated a regional IPM outreach program for weed management in field corn. He is also currently developing programs in vegetables and turf. For the past five years he has also been the instructor for the Ecology and Control of Weeds course in the Plant Science Department. Resume available upon request.

Cohen Farms- Commercial pumpkin growers.

Cohen Farms located in Ellington, CT has been growing pumpkins on their farm for many years. Currently 100 acres of pumpkins are grown on this farm.

Project Budget

Project Period: Dec. 2002 - Dec. 2004

Funding Request
Funding Requested	Other Funding	Total Funding
$40,000	0	$40,000