INTEGRATED WEED MANAGEMENT IN HEMP: A MULTISTATE EFFORT TO EVALUATE PRACTICES AND DEVELOP RECOMMENDATIONS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: NEW
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 1026958
• Grant No.: 2021-70006-35311
• Project No.: NYG-632533
• Proposal No.: 2021-04894
• Program Code: ARDP
• Project Start Date: Sep 1, 2021
• Project End Date: Aug 31, 2024
• Grant Year: 2021

Project Director
Sosnoskie, L. M.

Recipient Organization
N Y AGRICULTURAL EXPT STATION
(N/A)
GENEVA,NY 14456

Performing Department
School of Integrative Plant Sci

Non Technical Summary
This is a multi-state/multi-regional, applied (single-function) research-led proposal addressing the Plant Protection Tactics and Tools CPPM focus area. There is a growing demand for hemp-derived products in the United States (US). Recent estimates suggest that hemp product sales in the US are valued at $700 million. Because of the crop's previous designation as a Schedule 1 Substance and history of criminalization, there is limited University-produced information describing best production practices, which includes integrated weed management (IWM). Our goals are 1) describe the competitiveness of grain, fiber, and floral hemp with weeds, 2) evaluate the efficacy and safety of integrated weed management practices in this emerging crop, and 3) develop and disseminate extension materials. Specifically, we propose studies, which will be conducted in NY, VA, SC, IL, and ND, to define the critical timing of weed management operations against common and troublesome weeds and describe the impacts of chemical, physical, and cultural practices on the suppression of unwanted vegetation. Results from robust and replicated studies will be shared with local, regional, and national stakeholders to reduce the knowledge gap that currently exists for this ancient, yet emerging, commodity. Ultimate outcomes of this work include increased grower knowledge regarding IWM in hemp, altered production practices, and enhanced agricultural productivity. This project supports the CPPM goal of sustainable food security through the improvement of IWM practices that increases IPM adoption and reduces environmental and human health risks while supporting farmer profitability.

Animal Health Component

0%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
213	2300	1140	100%

Knowledge Area
213 - Weeds Affecting Plants;

Subject Of Investigation
2300 - Weeds;

Field Of Science
1140 - Weed science;

Keywords

hemp

integrated weed management

multi-state

sustainable

weed control

Goals / Objectives
The demand for hemp (Cannabis sativa L.)-derived products, which includes textiles and fibers, food and feed, personal hygiene and nutraceutical/pharmaceutical products, and more, has created an economic opportunity for United States (US) growers. A recent congressional report estimated US hemp product sales at $700 million, with opportunity for growth predicted. Results from a survey supported by a US Department of Agriculture National Institute of Food and Agriculture (USDA NIFA) Supplemental and Alternative Crops (SAC) grant identified stakeholder (e.g. growers and processors)research and education priorities for the US. Concerns about regulatory issues and hemp markets were foremost on the minds of survey takers, although pest management was also determined to be an essential area of focus. More than 70% of respondents indicated that weed management was a 'very important' to 'extremely important' research topic. Additional hemp production factors that could affect hemp's competitive ability with weeds, such as planting considerations and seedling and plant growth, were also ranked as being 'very important' to 'extremely important'.Cannabis criminalization under the 1970 Controlled Substances Act (CSA) prevented US farmers from legally growing the crop until 2018, when the Farm Bill formally declared industrial hemp distinct from marijuana (H.R.2 2018). The prohibition against Cannabis also banned research on best agronomic practices in hemp, including the development of recommendations for the control of competing vegetation.?Cannabis'long legal history has resulted in a significant knowledge gap with respect to integrated weed management (IWM), which hinders growers' abilities to maximize crop yields. Consequently, US growers are producing hemp with a fraction of the information that is usually provided to other commodities by University research and extension personnel.The goal of this project is to increase grower knowledge about dual purpose (i.e. fiber/grain) and floral (i.e. CBD) hemp cultivar interactions with weeds and facilitate the adoption of effective weed control strategies. To achieve this, we are proposing research (R) and extension (E) objectives.R1: Dual purpose hemp.Part a: Describe dual purpose hemp competitiveness with weeds and define the CWFP as influenced by cultivar/phenotype.Part b: Evaluate the efficacy of cultural and physical weed management practices in dual purpose hemp.R2: Floral hemp.Part a: Describe floral hemp competitiveness with weeds and define the CWFP as influenced by cultivar/phenotype.Part b: Evaluate the efficacy of cultural and physical weed management practices in floral hemp.R3: Dual purpose and floral hemp phenotyping assays. Quantify crop architectural traits and relate these data to the outcomes in R1 and R2.E1: Engage in coordinated research-supported extension outreach efforts with data showcasing local and regional similarities and differences in crop and weed responses.

Project Methods
R1: Dual purpose hemp.Part a: Critical weed free period (CWFP) as influenced by cultivar/phenotype. We will select and evaluate three hemp cultivars inclusion at each field site based on 1) widespread use by growers, 2) broad availability, and 3) data from university hemp cultivar trials across the US including Cornell University and the S1084 Hemp Multistate Hatch Project. Field trials will be conducted across 4 site-years (IL and VA in years 1 and 2). The trial locations will have a history of high weed pressure to ensure competition. Conventional tillage, which is a common practice in hemp production, will be used prior to planting to ensure a weed-free area at planting and stimulate weed germination. We will evaluate CWFP by keeping plots weed free via manual hoeing or pulling until 0, 1, 2, 4, and 6 weeks after emergence and then allowing plots to become weedy. The CWFP treatments will be compared to a season-long weed-free control to determine yields of treated plots as a percentage of the weed-free control. Hemp growth and development and hemp and weed biomass will be collected and analyzed, statistically, via ANOVA and regression analyses.Part b: Weed management in dual purpose hemp. The experiment will be conducted across 4 site-years (IL and VA in years 1 and 2) to evaluate weed management approaches in dual purpose hemp. Site selection, land preparation, fertility, hemp cultivar selection criteria, seeding rate, and pest management will the same as R1 Part a above. We will use as single, commonly planted dual purpose hemp cultivar (such as 'Joey') as varietal differences are explored in part a of this objective. Factors to be evaluated include include 1) herbicides,2) row spacing, and 3)seeding rate.Hemp growth and development and hemp and weed biomass will be collected and analyzed, statistically. Hemp and weed interactions with/responses to other biotic and abiotic stresses will also be documented.R2: Floral hemp.Part a: Critical weed free period as influenced by cultivar/phenotype. Floral hemp trials will be conducted across 6 site-years (NY, SC, and ND in years 1 and 2) and will follow the same general trial establishment, experiment design, treatment structure, data collection, and data analysis protocols that were described in part R1a. Hemp cultivar selection at each field site will be based on 1) widespread use by growers, 2) broad availability, and 3) data from university hemp cultivar trials. The analysis will be conducted tsimilar to what is presented in R1a, although floral yield will be substituted for fiber and grain yield values and days after transplanting will be substituted for days after emergence for inclusion in the regression analysis models.Part b: Weed management in floral hemp. An experiment will be conducted across 6 site-years (NY, SC, and ND in years 1 and 2) to evaluate weed management approaches in floral hemp. Site selection, land preparation, fertility, and pest management will be the same as in R 2a above. We will use one transplanted, floral hemp cultivar (such as 'Cherry Wine') as varietal differences are explored in part a of this objective. The trial will be established as a randomized complete block design with 4 replications.Factors will include flame weeding, cultivation, and plastic mulching. A non-weeded check will be included for comparison.Hemp growth and development and hemp and weed biomass will be collected and analyzed, statistically, similar to R1bR3: Dual purpose and floral hemp phenotyping assays.Collection of quantitative data describing plant architecture will allow us to evaluate the role of crop phenotype in weed suppression. At least twenty different hemp varieties (split among dual purpose and floral types) will be included in a greenhouse trial with 4 replications per cultivar arranged as a randomized complete block design. This will also include the cultivars evaluated in R1 a,b and R 2a,b, plus additional accessions of interest. Plants will be scanned using the PlantEyeF500 multispectral imager at weekly intervals from the time they are 9 cm in height for 6 weeks.The greenhouse trials will be repeated twice and analyzed and the resultant data used to describe the effects of phenotype variability on hemp-weed interactions.E1: Coordinated extension showcasing results of R1, R2, and R3.Local and national efforts: Faculty from each state will feature this project in at least two presentation or field days per year at relevant extension and industry meetings in addition to social media channels (e.g. @LynnSosnoskie, @VTAgWeeds, https://www.facebook.com/hemp.vt/, @IllinoisHGA, @ILFarmBureau, and others). Team members have previously presented at 2018-2020 Virginia Industrial Hemp Field Days (Blackstone, VA), 2019 County Farm Bureau Meetings (Saline, Gallatin, Wabash Co., IL), 2019 Illinois Hemp Summit (Springfield, IL), 2019 Belleville Field Day (Belleville, IL), 2020 Hermiston Farm Fair Seminars and Tradeshow (virtual; Corvalis, OR), the 2020 Empire State Producers Expo (Syracuse, NY), the 2020 National Hemp Research & Education Conference (virtual), 2021 Southern Illinois Hemp Symposium (virtual; Carbondale, IL) and other venues. Events will be open to all growers, consultants, and other industry representatives involved in pest management activities. Additionally, university cooperative extension personnel will be invited to participate as this will expand the impact of our activities by indirectly reaching growers not involved in the project. Results from these trials will also be shared with licensed growers, cooperative extension personnel, agricultural/horticultural students at Co-PI institutions, neighboring agricultural and community colleges, and minority serving institutions, such as South Carolina State, an historic HBCU located in Orangeburg, SC, that Dr. Cutulle interacts with. National efforts will be centralized on eXtension platform. We will develop a webpage specifically for this project which will include information about the team members, project objectives, research reports, presentations, and videos. These engagement strategies reflect practices frequently used by the developing hemp industry.

Progress 09/01/22 to 08/31/23

Outputs
Target Audience:Hemp producers, agronomic and horticultural extension agents, crop consultants, and other hemp industry personnel in the Southern, Mid-Atlantic, Northeastern,Mid-Western, and Great Plains regions of theUnited States. University hemp teams and hemp researchers, undergraduate and graduate students taking hemp production courses at Cornell and other universities. Colleagues in theWeed Science Society of America, Northeastern Weed Science Society, and the North Central Weed Science Society. North Dakota Academy of Science members. IR-4 Project administrators, state agriculture and regulatory officials, and others involved in the commercial production of hemp in across the Eastern, Mid-Western, and Great Plains regions of theUnited States. International participants at the Fifth International American Moroccan Agricultural, Health, and Life Sciences Conference. Stakeholders subscribed to thegeneral mailing list of the Cannabis Science Center at SIUC.Stakeholders are diversewith respect to gender, age, race and ethnicity, in addition to their social, economic, and education backgrounds. This includesminority hemp farmers and processors,as well asnew farmers and small acreage farmersto growers with extensive training in commercial crop production. Changes/Problems:Adverse weather conditions delayed planting and crop establishment in several locations.Despite setbacks with respect to targeted planting dates, and early season crop-weed competion, all trials are progressing towards harvest. We anticipate that several impacted sites will have crops that reflect the agronomic potential for their geographies this season.Gage and Flessner slightly revised the protocol for year 2 (2023 growing season). Revisions included (1) reducing plot size, collecting weed biomass on only top 3 weed species (economic driver weeds first (Amaranthusspp. andAmbrosiaspp.) across the trial as determined by density counts) individually and the remaining weed species bulked into a fourth composite sample, (2) using a grass specific herbicide for part a to reduce hand weeding/labor, and (3) determining hemp biomass, height, and diameter by male/female. Additionally, variety 'Joey' (used in 2022) was unavailable for 2023 so it was replaced with 'Felina 32.' Thus, varieties selected for Part a in 2023 were 'Felina 32', 'JinMa', and 'NWG 2730'. Co-PI Sosnoskieis conducting additional hemp-weed competition trials in the greenhouse using genetic materials from the USDA hemp germplasm collection and the Cornell hemp breeding program. These trials will be specifically focused on evaluating the impacts of hemp seed size on establishment and competitive ability with weedsand comparing the comepetitiveness of feral versus cultivated germplasm. Weed control trials in NY have been modified to include the evaluation of a novel electric weeder for non-chemical suppression of unwanted vegetation in hemp. 2024 trials in New York will also include novel herbicide active ingredients to describe the efficacy and safety of possible chemistries for use in row middles; this addition was based on direct discussions with industry stekeholders regarding weed management needs. What opportunities for training and professional development has the project provided?Training and professional development has been provided to undergraduate students,graduate students, and techniciansthat assisted with initiation and maintenance of field trials. Work included transplant production, land preparation, planting, irrigation and fertilization, treatment application, and data collection. Undergraduate and graduate students in were also able to receive training on the Phenospex phenotyper at Clemson University. Trainees, including undergraduate students, also participated in the preparation of scientific posters, which included a Second Place award in the undergraduate competition at the 2022 North Central Weed Science Society annual meeting(Isaacs, G.D., Miller, E.J., Spoth, M.P., Flessner, M.L., Gage, K.L. (2022) The effect of planting density and herbicide program on weed control in hemp (Cannabis sativa L.)) at the North Central Weed Science Society 77th Annual Meeting, St. Louis, MO, December 5 to 8, 2022. A trainee under Dr. Cutulle is in the process of preparing a manuscript (Implementing Digital Multispectral 3D Scanning Technology for Rapid Assessment of Hemp (Cannabis sativa L.) Weed Competitive Traits) for submission to the journal Hort Technology. How have the results been disseminated to communities of interest?In addition to the published presentations (6) listed under project products section, a video hosted on Cornell Hemp's YouTube channel (https://www.youtube.com/watch?v=52wOfJ1KXVw&list=PLHPXm2Es8aQAJRifrJjLHK6uu5tIGMqiU&index=19&t=336s), contributions to a Cornell Hemp production manual (https://hemp.cals.cornell.edu/resources/new-york-state-cannabis-sativa-l-production-manual/),and an extension article detailing the registration of a novel herbicide active ingredient in hemp (https://hemp.cals.cornell.edu/2023/06/21/pre-emergence-herbicide-registration-for-hemp-in-new-york/), members of the project team guest lectured to undergraduate and graduate students interested in hemp production and spoke directly to industry stakeholders at extensionfield days. Gage, K.L. (2022) Developing Best Management Practices for Integrated Weed Management in Hemp. Science of Hemp. Lexington, KY. October 3-4, 2022. [Presentation] Sosnoskie, L. M. (2022) Weeds and Weed Management in Hemp.Cornell UniversityPLSC 5015 Hemp Production Systems. Ithaca, NY. [Course Lecture] Sosnoskie. L. M. (2023) Weed Management in Hemp.Cornell University High-cannabinoid Hemp (Cannabis sativa) Field Day. Geneva, NY. August 11, 2023. [Presentation] Hatterman-Valenti, H. (2022)Weed Management in Hemp.NDSU Fruit, Hemp, and Vegetable Field Day. September 15, 2022. [Presentation] Hatterman-Valenti, H. (2023) Weed Management in Hemp. NDSU Weed Science Field Day.Absaraka, ND. June 22, 2023. [Presentation] What do you plan to do during the next reporting period to accomplish the goals?Co-PIs and their research teams will harvest 2023-planted trials, enter and analyze data, and share results with local and regional stakeholders. Co-Pis will also acquire seed and trial materials for 2024 field studies. Research sites will be prepared for planting and the second year of trials will be established next spring and early summer (April, May, June). Members will also present on weed management in hemp at extension events, such as the Grain and Fiber Cornell Hemp field day on September 14, 2023. Members will conduct additional hemp-weed competition trials in the greenhouse using genetic materials from the USDA hemp germplasm collection and the Cornell hemp breeding program. These trials will be specifically focused on evaluating the impacts of hemp seed size on establishment and competitive ability with weedsand comparing the comepetitiveness of feral versus cultivated germplasm. Team members will collaborate with team to develop and expand the scope of extension materials. Team members will also prepare and submit research articles for formal publication in Weed Science Society of America Journals.

Impacts
What was accomplished under these goals? Team members purchased or received donated seed from industry partners and completed appropriate regualtory tasks required for hemp production in each state (e.g. background checks, planting reports, etc...). Forgrain and fiber hemp, Co-PIs Gage and Flessner completed hemp harvest for both parts a and b in September/October 2022 at their respective locations. Gage analyzed data from year 1. Gage and Flessner slightly revised the protocol for year 2 (2023 growing season). Revisions included (1) reducing plot size, collecting weed biomass on only top 3 weed species (economic driver weeds first (Amaranthus spp. and Ambrosia spp.) across the trial as determined by density counts) individually and the remaining weed species bulked into a fourth composite sample, (2) using a grass specific herbicide for part a to reduce hand weeding/labor, and (3) determining hemp biomass, height, and diameter by male/female. Additionally, variety 'Joey' (used in 2022) was unavailable for 2023 so it was replaced with 'Felina 32.' Thus, varieties selected for Part a in 2023 were 'Felina 32', 'JinMa', and 'NWG 2730'. Field trials for both parts a and b were planted in June 2023 and trial maintenance, data collection, and other activities have been executed to date at Gage and Flessner's respective locations. With respect to transplanted hemp, Co-PIs Transplanted hemp trials were established in South Carolina, New York and North Dakota. Hemp varieties have included 'Cherry Wine', 'Sour Space Candy', 'PhotoCBD', and 'Bubbatonic'. The 2023 studies are expected to be harvested in September or October of 2023. Co-PI Sosnoskie is establishing additional hemp-weed competition trials using accessions from the Cornell Hemp breeding program and the USDA Hemp Germplasm repository. Sosnoskie is also partnering with the Cornell Hemp program to screen harvested seed and baled stalks for weed and weed seed contamination. With respect to Objective R3, PI Cutulle along with graduate student Gursewak Singh have been conducting replicated greenhouse-based trials using the varieties included in R1 and R2, as well as other accessions of importance. An article entitled "Implementing Digital Multispectral 3D Scanning Technology for Rapid Assessment of Hemp (Cannabis sativa L.) Weed Competitive Traits" is being finalized for submission to the journal Hort Technology. Co-PIs have been engaed in education and outreach activities related to the project including presentations at regional and national professional society and extension meetings. Information about hemp competitiveness and managment success derived from the trials have been included in educational materials produced through Cornell University.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Sosnoskie, L. M. 2023. Hemp and weed competition in New York. 63rd Meeting of the Weed Science Society of America in Arlington, VA, January 31 to February 2, 2023.
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Hatterman-Valenti, H., Shikanai, A., and Auwarter, C. 2022. Is a critical weed free period needed for transplanted floral hemp? North Central Weed Science Society 77th Annual Meeting, St. Louis, MO, December 5 to 8, 2022.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Hatterman-Valenti, H., Auwarter, C., and Shikanai, A. 2023. How Competitive are Transplanted Floral Hemp? North Dakota Academy of Science 2023 Annual Meeting. Minot, ND, April 14, 2023.
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Williams, C.M., Miller, E.J., Spoth, M.P., Flessner, M.L., Gage, K.L. (2022) The effects of weed competition on hemp biomass accumulation. North Central Weed Science Society 77th Annual Meeting, St. Louis, MO, December 5 to 8, 2022. [undergraduate poster]
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Isaacs, G.D., Miller, E.J., Spoth, M.P., Flessner, M.L., Gage, K.L. (2022) The effect of planting density and herbicide program on weed control in hemp (Cannabis sativa L.). North Central Weed Science Society 77th Annual Meeting, St. Louis, MO, December 5 to 8, 2022. [undergraduate poster and 2nd Place award recipient in Undergraduate Poster Competition]
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gage, K. (2022) Weed and Crop Interactions in Cannabis Production. Proceedings of the Fifth International American Moroccan Agricultural, Health, and Life Sciences Conference (AMAHLS V Conference) and The First Cannabis & Hemp Sciences and Entrepreneurship Day (CHSE I), December 13 to 14, 2022, Tangier, Morocco. Atlas Journal of Biology 2023, pp. 768-892. https://doi.org/10.5147/ajb.vi.239

Progress 09/01/21 to 08/31/22

Outputs
Target Audience:Stakeholders include hemp farmers, retailers, crop consultants, agronomists, and seed producers. The target audiencealso includes university extension specialists engaged with hemp production/producers, undergraduate and graduate students taking hemp production courses, and state regulatory officials. Local stakeholdersare largely residents ofNew York, Virginia, Illinois, South Carolina and North Dakota, although the reach of team members extends to the Midwest, Northern Great Plains, Northeast, Mid Atlantic, and Southeast US through extension outreach channels (for example, the general mailing list of the Cannabis Science Center at SIUC). Stakeholders arediverse with respect to gender, age, and ethnicity, as well as their educational and economic status. Changes/Problems:Environmental conditions across the US delayed planting in most locations including IL, SC, ND and NY. In South Carolina, this included significant summer rainfall; heavy coastal South Carolina soils do not drain well and significant rainfall can be detrimental to crops such as hemp. Excessive rain and cold conditions were reported in both Illinois. In North Dakota and Illinois. Conversely, dry conditions in the Northeast US delayed crop planting. Despite setbacks with respect totargeted planting dates, and early season crop-weed competion, all trials areprogressing, successfully, towards harvest. We anticipate that several impacted sites will have crops that reflect the agronomic potential for their geographies this season. What opportunities for training and professional development has the project provided?Training and professional development has been provided to 10 undergraduate students (IL ND, NY, SC, VA),10 graduate students (SC, VA), and 4 technicians (IL, NY) thatassisted with initiation and maintenance of field trials. Work included transplant production, land preparation, planting, irrigation and fertilization, treatment application, and data collection,including hemp growth stages. Undergraduate and graduate students in SC were also able to receive training on the Phenospex phenotyper. How have the results been disseminated to communities of interest?Co-PIs Sosnoskie, Gage, and Hatterman-Valenti have presented preliminary results from the 2022 trials to local stakeholders at extension eventsheld at: Prosper, ND (July 7, 2022) - 50 attendees Absaraka, ND (August 15, 2022) - 100 attendees Belleville, IL (July 14, 2022) - 120 attendees Geneva, NY (August 11, 2022) - 70 attendees What do you plan to do during the next reporting period to accomplish the goals?Co-PIs and their research teams will harvest 2022-planted trials, enter and analyze data, and share results with local and regional stakeholders. Co-Pis will also acquire seed and trial materials for 2023 studies. Research sites will be prepared for planting and the second year of trials will be established next spring and early summer (April, May, June). Team members will begin formal collaboration to develop extension materials.

Impacts
What was accomplished under these goals? The research research team has met as a single, unified group and as smaller working teams (e.g. to address grain/fiber and floral hemp objectives). Results of these meetings solidified the selection of varieties to use in the trials and reinforced data collection metrics. Teammembers purchased or received donated seed from industry partners and completed appropriate regualtory tasks required for hemp production in each state (e.g. background checks, planting reports, etc...). With respect to objectives R1 and R2, competitiveness and weed control field trials were successfully established at all five locations. Co-PIs Gage and Flessner coordinated the grain and fiber studies, which includedvarieties 'Joey', 'JinMa', and 'NWG 2730'. Co-PIs Sosnoskie, Cutulle, and Hatterman-Valenti coordinated the floral studies, which included varieties 'Bubbatonic', 'Cherry Wine', 'Photo CBD', 'Sour Space Candy', 'Sour Spectrum', All research activities described in the protocol/proposal have been executed to date and the trials are progressing towards harvest (projected September-October 2022). With respect to Objective R3,PI Cutulle along with graduate student Gursewak Singh have been conducting replicatedgreenhouse-basedtrials using the varieties included in R1 and R2, as well as other accessions of importance. A proposed article "Optimization of a phenotyping system to calculate digital biomass in Hemp" is being prepared with the target journal 'HortScience'.

Publications