MAXIMIZING EFFECTIVENESS OF HERBICIDES TO ENHANCE PRODUCTION OF HORTICULTURAL CROPS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1009313
• Project No.: MICL02438
• Project Start Date: Jun 1, 2016
• Project End Date: Sep 30, 2019

Project Director
Zandstra, B.

Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824

Performing Department
Horticulture

Non Technical Summary
Weed control is a major concern and expense in production of fruit and vegetable crops. Weeds are competitive with crop plants for sunlight, nutrients, space, and water, which results in smaller crop yields, reduced quality, and higher costs to growers. Chemical herbicides are the most common method of controlling weeds in USA crop production. Herbicides are produced and sold by commercial companies with a profit motive. Pesticides are approved and regulated by the USEPA. To obtain new pesticide registrations, herbicides need to be tested extensively in the field to assure crop safety and efficacy of use. The USEPA requires several years of data to support label language. In addition, all new pesticide uses need to undergo field testing under proposed use conditions, and then be analyzed for potential pesticide residues in the edible portion of the crop. After a determination of no or negligible residues in the raw commodity, the labeling process may proceed. Continued use of herbicides with the same mode of action has resulted in many instances of weeds developing resistance to the herbicides. This has become a serious agronomic challenge in USA agriculture, including in horticultural crops. The primary method of managing weed resistance is application of herbicides with different modes of action than the ones to which resistance has developed. Finding effective alternative herbicides and obtaining registrations so the herbicides may be used in the various crops is a major objective of this research project.Weed control experiments will be conducted in various locations around Michigan in grower fields and in research stations on all major fruit and vegetable crops. Any new herbicides will be tested on all potential use crops to determine crop safety. Persistent, resistant, and noxious weeds will be targeted to clearly identify herbicides and herbicide combinations that provide acceptable levels of control. All experiments will be replicated in location and time. Results will be shared with growers at field days, winter educational meetings, and at annual state conferences. All data is published in paper and on line. Results also are presented at regional and national professional meetings. Data to support new herbicide registrations will be shared with IR4, USEPA, and state regulatory agencies.The ultimate goal of this research is to provide more weed control tools to growers of horticultural crops so that they can produce higher yields of their crops and thus support both their families and the economy of the state of Michigan. Higher quality crops will provide improved nutrition to American children and adults.

Animal Health Component

0%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
213	0199	1140	100%

Knowledge Area
213 - Weeds Affecting Plants;

Subject Of Investigation
0199 - Soil and land, general;

Field Of Science
1140 - Weed science;

Keywords

vegetable weed control

fruit weed control

weed resistance

herbicide mode of action

yield reduction

new herbicides

minor crops

culinary herb weed control

perennial crop weed control

herbicide combinations

Goals / Objectives
1. Determine potential of new herbicides for use in vegetable crops and optimal timing and rates of application.2. Obtain field research data to support registration of new herbicides and expand registrations of labeled herbicides for use in perennial bush and tree fruit crops.3. Confirm and verify putative weed resistance to herbicides in horticultural crops.4. Develop herbicide use programs for perennial crops that include multiple modes of action and timings to improve quantity and quality of crop production and reduce potential for weed resistance.

Project Methods
1. Replicated experiments will be conducted in field and greenhouse. All experiments will be analyzed using appropriate statistical methods. Results will be presented to growers at public meetings and in published research reports.2. Growers will be queried to determine the level of adoptation of new technology. Annual acreage increases or decreases will be evaluated based on NASS statistics. Projects will be modified to meet new requirements as the project progresses.

Progress 06/01/16 to 09/30/19

Outputs
Target Audience:All research progarms were established and conducted to interact with and engage fruit and vegetable crop growers, professional crop consultants, and Extension Educators. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Meetings were held with Extension Educators and private crop consultants on specific weed control problems and crop injury situations. Emphasis was placed on diagnosing problems and proposing solutions. Participants were encouraged to collect evidence regarding potential herbicide drift or misapplication, including photos of the injury, spray records, weather data, and other relevant information. How have the results been disseminated to communities of interest?Grower meetings are held in various parts of the state to educate growers on current and new information regarding crops grown in their areas. An annual state-wide meeting is held in December in Grand Rapids, Michigan, at which all major fruit and vegetable crops are included in educational sessions. New herbicide labels are announced in articles posted to MSU News. Articles also are placed in grower newsletters and newspapers. Crop production bulletins that contain herbicide recommendations are updated annually. Information with potential wider interest is submitted for peer-reviewed publication, either in print or in digital format. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? 1. Vegetable crops were treated with registered and new herbicides to determine effective methods for use and to obtain data for registration. Bicyclopyrone and pyroxasulfone have been applied to all major vegetable crops. Bicyclopyrone will be labeled for garlic, and possibly for dry bulb onion. It also may be labeled for broccoli and other heading brassicas. Pyroxasulfone was labeled for celery and was safe on seeded dry-bulb onion and green onion and on transplanted leek. Prometryn was safe on transplanted leek. Acifluorfen was effective for weed control and did not cause crop injury when applied preemergence to basil. Pyridate has been safe when applied postemergence to mint and brassica heading vegetables. Indaziflam provided good weed control and did not injure asparagus when applied to dormant asparagus in the fall or early spring. It provided good weed control through the harvest season. Quinclorac was effective for postharvest control of field bindweed and Canada thistle in asparagus. Broccoli, cilantro, dill, and rhubarb were added to the clomazone label. 2. Research was conducted to expand herbicide labels for small fruit and tree fruit crops. Hops were added to the dimethenamid label. A new mesotrione label includes pome and stone fruit and nut trees. These labels add new modes of action for fruit crops, which will improve weed control and help to avoid herbicide resistance. 3. Herbicide resistant weeds continue to cause problems in vegetable crops. Several amaranth species have been demonstrated to be resistant to the Photo system II inhibitor herbicides. A recently-introduced amaranth species, livid amaranth, has been collected from Michigan celery fields. It appears to be resistant to PS II inhibitors, but susceptible to PPO inhibitors. 4. Indaziflam provided good long-term control of most weeds in fruit crops. Combinations of herbicides with different modes of action provided good season-long control of most weeds. Indaziflam plus saflufenacil, indaziflam plus pyroxasulfone, indaziflam plus pendimethalin, and indaziflam plus rimsulfuron provided excellent long term weed control in apples. Other effective combinations were simazine plus indaziflam, simazine plus rimsulfuron, sulfentrazone plus diuron, and sulfentrazone plus pendimethalin. Preemergence application of two residual herbicides with different modes of action plus a contact herbicide, followed by a second application of two different herbicides in mid-season resulted in a high level of weed control throughout the growing and harvest seasons.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Zandstra, B. 2019. Asparagus weed control past, present, and future. WSSA Abstracts 59:458.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Kaya-Altop, E., Jabran, K., Phillippo, C., Zandstra, B., Mennan, H. Effect of different water management strategies on competitive ability of semi-dwarf rice cultivars with E. oryzoides. Crop Protection 116:33-42.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Fruit and vegetable growers in Michigan. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Several meetings were held with Extension Educators, industry crop advisors, and interesed growers to view and discuss weed control issues. New labels and new methods were reviewed in all meetings. How have the results been disseminated to communities of interest?All new herbicide registrations and label changes are announced in print and on-line in MSU News. Articles are published in agricultural publications. New recommendations are published in annual updates to MSU crop production and pest management guides. What do you plan to do during the next reporting period to accomplish the goals?Recently-labeled herbicides will be included in 2019 experiments. Data will be collected to support additional new uses through IR-4. New labeled uses will be included in grower demonstrations.

Impacts
What was accomplished under these goals? 1. Vegetable crops were treated preemergence or postemergence with bicylopyrone to determine crop safety and effective weed control rates and timings. Bicyclopyrone applied preemergence in the fall to seeded garlic did not injure garlic or reduce yield. Tolpyralate applied postemergence to sweet corn had excellent crop safety and controlled most broadleaf and grass weeds. Saflufenacil caused crop stunting when applied preemergence or postemergence to native spearmint. Pyroxasulfone applied delayed preemergence or at the one or two leaf stage of green onion and leek on muck soil provided good control of common purslane and redroot pigweed and good crop yields. Sulfentrazone provided good preemergence control of broadleaves and grasses in basil and had good crop safety. 2. Research was conducted in blueberry and tree fruits to obtain new herbicide labels. Quinclorac was labeled for use in blueberry and caneberry. It controlled barnyardgrass, large crabgrass, yellow foxtail, Canada thistle, perennial sowthistle, morningglory, and field bindweed. Improved weed control should improve returns to growers at $2 million per year. 3. Powell amaranth and redroot pigweeds collected from asparagus fields were treated in the greenhouse with herbicides to determine level and scope of herbicide resistance. Most of the accessions were resistant to photosystem II inhibitor herbicides and ALS inhibitor herbicides. None were resistant to PPO inhibitor herbicides. In a field experiment, indaziflam provided good control of resistant pigweeds. 4. Maximum weed control was obtained in apples with combinations of residual and foliar-active herbicides. Indaziflam plus diuron plus glufosinate preemergence provided excellent season-long control of most weeds. Sulfentrazone plus oryzalin plus diuron plus paraquat, and flumioxazin plus diuron plus glyphosate also provided excellent season-long control of broadleaf weeds and grasses. Postemergence treatments of quinclorac, fluroxypyr plus clethodim, glyphosate plus pyraflufen, and saflufenacil plus pyraflufen provided good to excellent control of broadleaves and grasses. A low-volatile choline formulation of 2,4-D was effective against broadleaves and caused no crop injury in apple and cherry. Use of effective preemergence and postemergence herbicide combinations should provide 10% greater fruit yield and improve quality by reducing competition for nutrients and water and by removing habitat for pests.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Phillippo, C., Zandstra, B. 2018. Integrated vegetable weed management with bicyclopyrone. WSSA Abstracts. 58:344.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Zandstra, B., Phillippo, C. 2018. The final word in onion weed control. WSSA Abstracts 58:332.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:All research and programs were performed to support and engage the horticultural crop growers in Michigan and surrounding states. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Weed control research was conducted at research stations and in grower fields. Field days were held at several locations for public education. Extension educators were encouraged to participate in all research activities. How have the results been disseminated to communities of interest?Articles on new information about weed control were published in popular press and in refereed journals. New labels are included in weed control guides. All research data is posted on the MSU website. What do you plan to do during the next reporting period to accomplish the goals?Results of 2017 experiments will be analyzed and new discoveries included in 2018 experiments. More registration projects will be conducted with IR4. All 2017 data will be shared with growers and other interested persons.

Impacts
What was accomplished under these goals? 1. Onions on mineral and organic soils were treated with bicyclopyrone pre- and postemergence. Onions were tolerant of bicyclopyrone applied pre at 0.033 lb per acre. In combinations with bromoxynil and pendimethalin, bicyclopyrone improved control of ladysthumb. There was no adverse effect on onion yield, and weed control was improved throughout the season. Bicyclopyrone applied postemergence in onion with oxyfluorfen improved ladysthumb and redroot pigweed control throughout the season. On mineral soil, bicyclopyrone applied preemergence improved common lambsquarters and hairy nightshade control. The improved weed control with bicyclopyrone in onion will result in a $2 million increase in net income to growers. 2. Herbicide efficacy trials were conducted on several vegetable crops, apple, blueberry, grape, and hops. Twelve registration projects were conducted with IR4. New registrations will result in improved quality of fruit and vegetable crops and greater yields. Grower expenses should decrease by 10% and profit should increase by 10%. 3. Powell amaranth and redroot pigweed have putative resistance to PSII inhibitor herbicides. In experiments in asparagus, the resistant weeds were controlled by herbicides with other modes of action, including an ALS inhibitor and a PPO inhibitor. In Christmas trees, common ragweed that survived clopyralid in the field had a 10X level of resistance to clopyralid when tested in the greenhouse. 4. In apple, a premix of indaziflam plus rimsulfuron provided very broad-spectrum grass and broadleaf weed control. Addition of glufosinate or glyphosate improved control of most weeds and provided 4-5 months of acceptable weed control. Addition of pyraflufen to glyphosate improved desiccation of most broadleaf weeds. Improved weed control should reduce grower expenses and improve net returns by 10%.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Phillippo, C., Zandstra, B. 2016. Managing weeds in pepper and tomato with new herbicides. NCWSS Proceedings 71:180.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Zandstra, B., Phillippo, C. 2016. Controlling weeds in strawberry throughout the year. NCWSS Proceedings 71:179.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Phillippo, C., Zandstra, B. 2017. Bicyclopyrone in vegetable weed management. WSSA Abstracts 57:312.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Zandstra, B., Phillippo, C. 2017. Weed management in asparagus with new herbicides. WSSA Abstracts 57:311.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Herrmann, C., Goll, M., Phillippo, C., Zandstra, B. 2017. Postemergence weed control in onion with bentaon, flumioxazin, and oxyfluorfen. Weed Technology 31:279-290.

Progress 06/01/16 to 09/30/16

Outputs
Target Audience:The target audience for the weed control research is fruit, vegetable, and Christmas tree growers; Extension educators, chemical industry personnel, food processing company field persons, crop consultants, state registration managers, and federal regulators. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Extension educators, growers, and undergraduate students were included in all research projects. Several experiments were conducted in grower fields and growers were encouraged to participate in the research. How have the results been disseminated to communities of interest?Research reports for all weed control experiments are posted on the MSU website. All registration project data is sent to IR-4, which then shares it with USEPA. Information on new registrations that have been issued is posted on the MSU News website. Articles are written for popular journals. What do you plan to do during the next reporting period to accomplish the goals?All data from 2016 will be analyzed and posted on the MSU website. It also will be published in Horticulture Report 80, 2016. Greenhouse research will continue to verify herbicide resistance in common purslane, common ragweed, and horseweed. Field research and IR-4 residue and efficacy trials will be conducted during 2017. Data collected in 2016 will be presented at grower meetings during the winter months of 2016 and 2017.

Impacts
What was accomplished under these goals? 1. Pyroxasulfone provided good control of ladysthumb and redroot pigweed in onion. It was safe on onions after the two leaf stage. Pyroxasulfone was safe on celery after transplanting, and gave good control of annual bluegrass, barnyardgrass, common purslane, and redroot pigweed. Improved weed control in celery should increase gross returns to celery growers by 10%, which will result in an increase of $2 million per year to Michigan growers. Bicyclopyrone was safe on onions postemergence and provided good suppression of annual grasses, ladysthumb and hairy nightshade. Improved weed control in onion should result in a 10% yield increase, which results in a return of $1.5 million per year to the Michigan onion industry. 2. Forty four weed control efficacy, phytotoxicity, and yield trials were conducted on fruit, vegetables, hops, and Christmas trees in 2016. Sixteen residue and crop safety trials were conducted under direction of IR-4. Two trials were conducted in cooperation with Agriculture and Agri-food Canada. The data obtained in these trials will be used to support new pesticide registrations and labels for these crops. 3. Putative herbicide-resistant common purslane was treated in the field with various herbicides to determine the nature of the resistance. Common ragweed and horseweed that survived clopyralid application was collected and will be tested in greenhouse experiments. 4. Combinations of idaziflam plus glufosinate plus glyphosate, indaziflam plus rimsulfuron plus glufosinate plus glyphosate, and sulfentrazone plus carfentrazone plus diuron plus glyphosate, applied in early spring provided season-long annual weed suppression in apples.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Phillippo, C., Goll, M., Zandstra, B. 2016. Pyroxasulfone for weed control in carrot, celery, and onion on high organic soil. WSSA Abstracts 56:523.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Zandstra, B. Goll, M., Phillippo, C. 2016. Vegetable weed control with pyroxasulfone. NEWSS Abstracts 70:308.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Zandstra, B., Goll, M., Phillippo, C., 2016. Vegetable weed control with bicyclopyrone. WSSA Abstracts 45:522.