DEVELOPING NON-CHEMICAL WEED CONTROL IN HAZELNUT - COMPARING SATURATED STEAM AND ELECTRIC WEED CONTROL

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 1024241
• Grant No.: 2020-70006-32982
• Cumulative Award Amt.: $292,649.00
• Proposal No.: 2020-07418
• Project Start Date: Sep 1, 2020
• Project End Date: Aug 31, 2023
• Grant Year: 2020
• Program Code: [ARDP]- Applied Research and Development Program

Recipient Organization
OREGON STATE UNIVERSITY
(N/A)
CORVALLIS,OR 97331

Performing Department
Horticulture

Non Technical Summary
This is an ARDP single-function research project focused on Plant Protection Tools and Tactics. We propose to evaluate the efficacy of saturated steam and electric weed control as components of a non-chemical weed management program. These novel technologies can fundamentally change weed management in hazelnut to mitigate herbicide resistance. Herbicide resistance is the greatest weed management challenge identified in multiple commodities. In Oregon hazelnut orchards, there are confirmed cases of resistance and multiple-resistances to all post-emergence herbicides, jeopardizing herbicide mixtures and rotations as a management tool. The use of non-chemical weed controls like tillage is limited in hazelnut because the nuts are harvested from the orchard floor, requiring a litter-free and firm soil surface. Our approach includes field research in collaboration with growers and on University farms. Neither saturated steam nor electric weed control disturbs the soil, making them compatible with hazelnut. Our objective is to evaluate the effectiveness and crop safety of the novel tools as they compare to mowing or herbicides. We propose to test tools in orchard middles and within tree rows, an area of the orchard often managed exclusively with herbicides. Experiments will determine safe rates for steam and electricity applications while optimizing weed control. This project will help identify effective non-chemical weed management tools compatible with tree nut production. The expected outcomes include a reduction in herbicide reliance, mitigation of herbicide resistance costs, and reduced human exposure to chemicals. Our findings will have applications to a wide range of other woody perennial crops.

Animal Health Component

100%

Research Effort Categories

Basic

0%

Applied

100%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
216	1210	1140	100%

Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
1210 - Filbert;

Field Of Science
1140 - Weed science;

Keywords

electric weed control

resistant weed

saturated steam

non-chemical weed management

Goals / Objectives
This proposal aims to develop and integrate two promising new technologies, contributing to high priority pest management issues (herbicide-resistance) and reduced herbicide reliance by promoting non-chemical weed management. This project will develop saturated steam and electric weed control as weed management alternatives, both ecologically prudent and safe to humans. We will assess how these emerging technologies can be effectively integrated into the cropping system to be affordable and environmentally sound. The development and introduction of new Plant Protection Tools and Tactics will diversity current weed management programs. The outcomes will be reduced dependence on herbicides and an effective non-chemical tool to mitigate resistance, spread, and selection of resistant weed biotypes.Objective 1: Characterize the use of saturated steam and electric weed control for post-emergence. (research oriented) Obj 1.1 - determine the effectiveness of both technologies over weed species and densities.Obj 1.2 - determine hazelnut tolerance to saturated steam and electric weed control.Objective 2: Evaluate saturated steam and electric weed control in commercial hazelnut orchards. (research oriented)Obj 2.1 - row-middle weed control as compared to standard practice (mowing and post-emergence herbicides);Obj 2.2 - tree-row weed control as compared to standard practice (herbicides);

Project Methods
Obj 1.1 - determine the effectiveness of both technologies over weed species and densities.Activities proposed: The goal of this study is to establish uniform weed density and height to evaluate the effectiveness of saturated steam and electric weed control. We will use cover crops as weed surrogates. The experimental design will be a four-factor factorial with three surrogate weed species, two planting densities, two weed control methods, and six rates. The experiment will be initiated when cover crops are between 10 and 30 cm height. Three cover species will be compared: annual ryegrass (Lolium perenne L multiflorum), white clover (Trifolium ripens), and buckwheat (Fagopyrun esculentum). Plants will be sown at two planting densities to target low and high densities, or 25 and 250 plant m-2, respectively. Species will be sown with a 3-meter-wide direct seeder; species will be randomly planted adjacent to one another. Treatments will be applied perpendicular to the planting direction to allow all three species to be treated on a single pass. We propose to compare six herbicide rates as follows: half-, full-, 2x-, 4x, and eight-times the manufacturer's recommended dose. A nontreated check will be included. Each experimental unit will be 5 m long and 2 m wide to allow an alley for the tractor. We will record plant density by species before and after treatment. Visual estimates of weed control on a scale of 0 to 100 (0 = no control and 100% = complete control). Plant height and above-ground dry biomass will be recorded four weeks after treatment to allow for regrowth. The experiment will be organized as a 2 by 6 by 3 by 2 factorial randomized complete block design with four replicates. The first factor is the two weed control methods (steam vs electricity), the second is the six rates, the third is the weed surrogates, and the fourth factor is planting density. There will be 288 2 by 5 m plots in an 0.3 ha of the research area. The study will be repeated.Data will be analyzed using a generalized linear mixed model with the three factors as fixed factors and the experimental block and experimental run as random factors. Weed control will be analyzed using a beta-distribution to better describe percent and proportional data sets (Douma and Weedon 2019). Weed biomass will be submitted to analysis by non-linear regression (Price et al. 2012). The treatment rate causing 90% biomass reduction will be used to compare species susceptibility and density impact.Obj 1.2 - determine hazelnut tolerance to saturated steam and electric weed control.A hazelnut field will be planted on the research farm. Trees will be planted in the fall of 2020 at 2.5 by 5 m to allow tractor operation between rows. The following spring, these field-grown trees will be used in crop tolerance to steam and electricity trials by varying rates as describe in the previous section. Young trees are generally more sensitive to weed control practices and will serve as good indicator of crop damage. Treatments will be applied to both sides of the tree row, mimicking a commercial practice. Saturated steam will be applied using a 0.9 m applicator; electricity will be applied using a 0.6 m applicator. The experiment will consist of two hazelnut varieties (i.e. Yamhill and McDonald's), two weed control methods (steam and electric), six rates, and four replicates. Each replicate will consist of two plants of each variety per treatment. Each tree will be treated four times during the season to simulate the timing of common weed control practices (winter, early spring, early summer, late summer). Plants will be treated in 2021 and again in 2022 to monitor a two-year effect.Data collection. We will evaluate injury using visual estimates, monitor trunk growth, shoot length, canopy volume, and plant height. In representative plants, tree surface temperature and vascular cambium temperature will be monitored using a fine thermocouple (Dickinson 2002). A 0.5 mm type-k thermocouple will be connected to a data logger, to permit monitoring the temperature in the air, on the bark surface, and below the bark. Temperatures will be recorded every second for the duration of the exposure to allow quantification of temperature change at each monitoring site. Tissue damage will be assessed visually by microscopy and with destructive sampling of representative plants at the end of two years. Cuttings will be collected and exposed to a tetrazolium test (Jones et al. 2006). Plant vigor and development will be monitored in the current and following season to account for possible damage to young shoots by steam during the application season. The experiment will be a factorial randomized complete block design with four replicates. Each replicate will consist of four hazelnut plants, two of each variety. Data will be analyzed, as previously described. Objective 2: Evaluate saturated steam and electric weed control in commercial hazelnut orchards.Obj 2.1 - row-middle weed control as compared to standard practice (mowing);Obj 2.2 - tree-row weed control as compared to standard practice (herbicides);Replicated trials will be conducted in the Willamette Valley, OR commercial hazelnut orchards of the collaborators. The goal of this work is to compare the effectiveness of saturated steam and electric weed control to standard practice in row middles and tree-rows. Hazelnut orchards with natural weed infestation will be selected. Weed presence and stage of development will be recorded before treatments. Volumetric soil moisture will be measured with a portable instrument (HS2, Campbell Scientific, USA) at the beginning of the experiment. The treatments will include: (1) nontreated check, (2) saturated steam low rate, (3) saturated steam high rate; (4) electricity low rate, (5) electricity high rate, and (6) grower standard. Low and high rates will be determined based on results of Obj 1 to ensure adequate crop safety and desired weed control level. For the row middles experiments, the standard treatment will be mowing, and for the tree-row experiments, the standard will be glufosinate at 1.1 kg active ingredient per ha applied at 187 liter per ha. The row middle experiment will be conducted spring - summer, when mowing is practiced. The tree-row experiment will be conducted both in dormant (fall or winter) and growing season (spring - summer) to capture differences in environment and weed populations.The experiment will be conducted for four weeks with assessments, including percent weed control per species, weed biomass, weed frequency, and above-ground biomass. Crop damage will be visually evaluated. The total time and resources (e.g., fuel, pesticide) involved in weeding practices will be recorded to evaluate input differences. We will consider the cost of acquisition, maintenance, and depreciation of implements, tractor, labor. The cost analysis will use ASAE methods (ASABE 2011; Fennimore et al. 2014). and will serve as a comparator for growers (short-term), and more importantly, can be used in future studies aiming to compare the profitability of adoption novel technologies, as was seen with abrasive weed control (Wortman et al. 2020).The experimental design will be a randomized complete block with four replicates. As the variability among weed species and density in commercial orchards are expected to be larger, we plan to selected three areas with a more uniform weed presence within the plot (Onofri et al. 2010) to increase experimental precision. Data will be submitted to analysis of variance using a generalized linear model and means separated by Tukey's test (P<0.05). Experiments in row middles versus tree row will be treated as separate experiments. Treatments and the experimental year will be treated as fixed factors. The block and its interactions will be considered random effects. The experiments will be conducted at two locations each year (2021-2022) for a total of four field sites.

Progress 09/01/20 to 08/31/23

Outputs
Target Audience: Hazelnut growers Oregon Hazelnut Commission Organic producers Small fruit producers Hop growers Stone and Pome fruit growers Vegetable Growers Changes/Problems:Problems with the steam equipment in the first year of trials removed associated treatments from the trials. Objectives 2.1 and 2.2 were combined as early results indicated electricity posed no danger to the crop. What opportunities for training and professional development has the project provided?One Ms students James Wirth - expected graduation 2025. One Post doctoral researcher added to the research group - Rafael Pedroso. One undergraduate researcher trained - Leah Mowery. A field day was organized for growers at Lewis Brown farm in September 2023. Extension Blog - Weeders of the West: Can electricity aid in the fight against herbicide-resistant Italian ryegrass? Feb 2023 How have the results been disseminated to communities of interest?Extension Blog. New Technology for Weed Management, Weed Science Society of America, Arlington, VA, January 30, 2023, Duration: 4 hours, (90 What do you plan to do during the next reporting period (October 2021 through September 2022.) to accomplish the goals? Moretti, M. L*., AgriWorld - Resilience and sustainability of hazelnut farming - a regenerative approach, "Exploring electric weed control in Hazelnuts," Potenza, ITA. (May 19, 2023). * Invited speaker. International symposia in Potenza, ITALY. Invited speaker. 280 contacts What do you plan to do during the next reporting period to accomplish the goals?Steam treatment was not applied in any of the objectives because of problems with the equipment in first year of the study. The research in electricity was conducted. Our initial results indicated no concern for crop safety, so we combined Obj 2.1 and 2.2.

Impacts
What was accomplished under these goals? Steam was not performed in any of the objectives because of problems with the equipment in first year of the study. 1.1 Eight field studies were conducted to evaluate the effectiveness of the electric weed control targeting primarily Italian ryegrass. We documented the initial population size and density and its response to electricity at different voltage levels and rates. We recorded weed control, biomass, seed production, viability, and vigor. 1.2. A long-term study was established at the OSU LB farm in Corvallis comparing soil tillage to electricity applied at two levels (high and low) and with and without suckers. Treatments were applied to the same plots four times per season for three years. Tree growth, yield, and quality were monitored in the period. Objectives 2.1 and 2.2 were combined once we learned that electricity was safe to the trees. Three field studies were conducted in the commercial fields infested with herbicide-resistant Italian ryegrass. Electric treatments were compared to herbicide glufosinate, mowing, or combinations of electricity, herbicides, or mowing. We recorded weed control, shoot and inflorescence biomass, and the effect on seed vigor and viability.

Publications

• Type: Journal Articles Status: Published Year Published: 2023 Citation: Moretti, M. L., Wirth, J., Munhoz Pedroso, R. (2023). Exploring electric current for weed control in hazelnuts (vol. 1379). Acta Horticulturae

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

Outputs
Target Audience: Hazelnut growers Oregon Hazelnut Commission Organic producers Small fruit producers Hop growers Stone and Pome fruit growers Vegetable Growers Changes/Problems:We combined Objectives 2.1 and 2.2 once our initial results indicated no concern for crop safety. What opportunities for training and professional development has the project provided?MS Degree James Wirth - expected graduation June 2025 Undergraduate student - Leah Mowery - student helper One Post doc - Rafael Pedroso. A field day was organized for growers at Lewis Brown farm in September 2023. How have the results been disseminated to communities of interest?Extension Weeders of the West Blog: Can electricity aid in the fight against herbicide-resistant Italian ryegrass? Feb 2023. New Technology for Weed Management, Weed Science Society of America, Arlington, VA, January 30, 2023, Duration: 4 hours, (90 participants). Moretti, M. L*., AgriWorld - Resilience and sustainability of hazelnut farming - a regenerative approach, "Exploring electric weed control in Hazelnuts," Potenza, ITA. (May 19, 2023). * Invited speaker. International symposia in Potenza, ITALY. Invited speaker. 280 contacts What do you plan to do during the next reporting period to accomplish the goals?This is the final report.

Impacts
What was accomplished under these goals? Objective 1: Characterize the use of saturated steam and electric weed control for postemergence. Steam was not performed in any of the objectives because of problems with the equipment in first year of the study. 1.1 Eight field studies were conducted to evaluate the effectiveness of the electric weed control targeting primarily Italian ryegrass. We documented the initial population size and density and its response to electricity at different voltage levels and rates. We recorded weed control, biomass, seed production, viability, and vigor. 1.2. A long-term study was established at the OSU LB farm in Corvallis comparing soil tillage to electricity applied at two levels (high and low) and with and without suckers. Treatments were applied to the same plots four times per season for three years. Tree growth, yield, and quality were monitored in the period. Objective 2: Evaluate saturated steam and electric weed control in commercial hazelnut orchards. Objectives 2.1 and 2.2 were combined once we learned that electricity was safe to the trees. Three field studies were conducted in the commercial fields infested with herbicide-resistant Italian ryegrass. Electric treatments were compared to herbicide glufosinate, mowing, or combinations of electricity, herbicides, or mowing. We recorded weed control, shoot and inflorescence biomass, and the effect on seed vigor and viability.

Publications

• Type: Journal Articles Status: Published Year Published: 2023 Citation: Moretti, M. L., Wirth, J., Munhoz Pedroso, R. (2023). Exploring electric current for weed control in hazelnuts (vol. 1379). In press in Acta Horticulturae

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

Outputs
Target Audience: Hazelnut growers Oregon Hazelnut Commission Organic producers Small fruit producers Hop growers Stone and Pome fruit growers Vegetable Growers Changes/Problems:Our objectives were delayed this year because of equipment malfunctions. We had purchased a new tractor in 2021 dedicated to this study, but in June of 2022 failure of the diesel exhaust unit forced delay of research activities for 3+ months. Accordingly, two studies for Obj 1.1 were lost, and were reinitiated in August 2022. We ordered new applicators that allow us to treat a continuous 4 ft swaths rather than two of 2 ft. The first applicator will allow us to treat weeds in the row middles, and the second one has a longer flexible extension arm to reach the weeds within the row. We ordered these applicators in November 2021, but have not received them as of October 2022; estimated delivery expected November 2022. A second tractor was ordered in June 2022 to avoid equipment and we await delivery . Three new front-mounted three-point hitch brackets were ordered and delivered in July 2022. These brackets allow us to operate the EWC equipment with 3 different tractors. What opportunities for training and professional development has the project provided? A master's student is currently working on the project and two undergraduate students assist. Multiple growers and members of the industry have seen the new technology in use, and the extension events have attracted the attention of growers of multiple crops, including a demonstration during the X International Hazelnut Congress How have the results been disseminated to communities of interest?https://www.farmprogress.com/tree-nuts/electric-weed-control-being-examined-hazelnuts https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=52287 What do you plan to do during the next reporting period to accomplish the goals?Expand on Objective 2.1 and 2.2 with better equipment, and otherwise respond to the submitted scope of work on the timeline indicated.

Impacts
What was accomplished under these goals? Obj 1.1 - determine the effectiveness of both technologies over weed species and densities. Three field studies are ongoing in 2022 to evaluate performance of the electrical weed control equipment in Italian ryegrass at different densities. Obj 1.2 - determine hazelnut tolerance to saturated steam and electric weed control. Obj 1.2 A field study was established at the Lewis Brown research farm. Treatments include nontreated, tillage, EWC at high and power after removing tree suckers, EWC at low and power after removing tree suckers, and EWC and high and low power applied to tree suckers. These six treatments are replated six times and include two important hazelnut varieties grown in Oregon Obj 2.2 - tree-row weed control as compared to standard practice (herbicides). We ordered two new applicators more appropriate for in row and between row experiments in commercial fields. One unit is being built locally and the second unit was imported.

Publications

• Type: Other Status: Published Year Published: 2021 Citation: Moretti, M. L. (2021). Using Electricity to Manage Herbicide-Resistant Ryegrass Pacific Nut Producer Magazine.
• Type: Websites Status: Published Year Published: 2022 Citation: Moretti, M. L. 2022 Can electricity aid in the fight against herbicide-resistant Italian ryegrass?. https://smallgrains.wsu.edu/weeders-of-the-west/
• Type: Conference Papers and Presentations Status: Other Year Published: 2022 Citation: Regional Wirth, J. R.* - Author & Presenter, Pedroso, R. M. - Author, Moretti, M. L. - Author, "Hazelnut crop safety using electric weed control," Western Society of Weed Science,Newport Beach, CA. (March 2022). Pedroso, R. M. - Author & Presenter, Moretti, M. L. - Author, "Italian ryegrass control with electricity in hazelnut orchards," California Weed Science Society, Sacramento, CA. (January 20, 2022).
• Type: Conference Papers and Presentations Status: Other Year Published: 2022 Citation: National Wirth, J. R.* - Author, Pedroso, R. M. - Author, Moretti, M. L. - Author & Presenter, "Italian ryegrass (Lolium perenne spp. multiflorum) with electric current in hazelnut orchards," Weed Science Society of America, Vancouver, BC, CAN. (February 2022).
• Type: Conference Papers and Presentations Status: Other Year Published: 2022 Citation: International Moretti, M. L. - Author & Presenter, "Exploring electric current for weed control in hazelnuts," X International Congress on Hazelnut, Corvallis, OR. (September 5, 2022).

Progress 09/01/20 to 08/31/21

Outputs
Target Audience: Hazelnut growers Oregon Hazelnut Commission Organic producers Small fruit producers Hop growers Stone and Pome fruit growers Vegetable Growers Changes/Problems:Our greatest challenges were the travel and hiring limitations related to the pandemic. The EWC equipment was delivered a month and half later than expected, arriving in early December 2019. Unfortunately, travel restrictions prohibited the technical delivery. In January, we assembled the equipment ourselves and initiated testing. OSU units were under a hiring freeze during most of 2020 and early 2021. As a result, hiring the post doc was severely delayed. The post doc hire was completed recently, and the selected candidate will start in early October. Quickly we noticed that the manufacturer recommended 75 hp tractor power was insufficient for the soil conditions in Oregon. With the help of the Department and the College, we purchased a 105 hp tractor that we put to use in April 2021. The new tractor required a different bracket to attach the EWC applicator, resulting in extra costs. Also in April 2021, we took possession of a trailer to transport the tractor and implement and secured a truck large enough to tow all apparatus needed. This equipment was secured with non-federal funds. We successfully initiated three field studies during the spring and summer 2021. Unfortunately, increased risk of fire hazards from dry plant litter in the field stopped these efforts. EWC is likely a viable option during fall-early summer for our ecological conditions. We are now improving the front bracket to allow proper control of applicator height and easier mount and dismount. We identified a company based in Yakima, WA, to make that improvement. Our next task is to develop a better way to apply electricity to the weeds around the tree base. These customizations are paid for with commission funds. What opportunities for training and professional development has the project provided?Training the next generation of agricultural scientists: a master's student is currently working on the project and two undergraduate students assisted with field trials. Multiple growers and members of the industry have seen the new technology in use, and the extension events have attracted the attention of growers of multiple perennial woody crops. Extension events: Moretti, Marcelo L. (February 2, 2021). Thermal Weed Control in Blueberry, Cornell New York State Tree Fruit Conference, Geneva, NY, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 340, Invited. Scope: State. Moretti, Marcelo L. (January 20, 2021). Update on Weed Management Research in Hop, American Hop Convention, Portland, OR, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 120. Scope: National. Moretti, Marcelo L. (January 14, 2021). Steam for weed control in organic blueberry, Empire State Producers Expo, Geneva, NY, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 113, Invited. Scope: National. Moretti, Marcelo L. (January 11, 2021). Weed Management-in Perennial Crops, University of California Seminar, online, Duration: 1 hours, Webinar, Series of 1 classes, Adult Contacts: 35, Invited. Scope: Local. Moretti, Marcelo L. (December 16, 2020). Weed Management strategies in organic perennial crops, Northwest Center for Small Fruit Research, online, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 50, Volunteered. Scope: Regional. Moretti, Marcelo L. (December 15, 2020). Managing Perennial Weeds in Blueberry, Pratum Coop Winter meeting, Salem, OR, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 35. Scope: Local. Moretti, Marcelo L. (September 14, 2020). Research updates in hazelnut weed management, Marion Ag Virtual Grower Meeting, Salem, OR, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 35, Invited. Scope: Local. Moretti, Marcelo L. (February 5, 2020). Updates on Sucker Control in Hazelnuts, Nutrien Ag Winter meetings, Salem, OR, Duration: 1 hours, Series of 1 classes, Adult Contacts: 50. Scope: Local. Moretti, Marcelo L. (December 5, 2019). Updates on Sucker Control in Hazelnuts, Nutrien Ag Winter meetings, Lebanon, OR, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 80. Scope: Local. Moretti, Marcelo L. (December 3, 2019). Weed Management strategies in organic perennial crops, Northwest Center for Small Fruit Research, Ferndalle, WA, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 50, Volunteered. Scope: Regional. Moretti, Marcelo L. (November 19, 2019). Updates on Sucker Control in Hazelnuts, Willbur Ellis Winter meetings, Albany, OR, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 80. Scope: Local. Moretti, Marcelo L. (November 13, 2019). Novel Floor Management Strategies, Eola-Amity Hills Winegrowers Association, Salem, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 30, Invited. Scope: Local. Moretti, Marcelo L., Author/Presenter. (October 30, 2019). Organic Weed Management in Blueberries, Oregon Society of Weed Science, Hood River, OR, Duration: 1 hours, Face to Face, Series of 1 classes, Adult Contacts: 100, Invited. Scope: State. How have the results been disseminated to communities of interest?A shocking Approach to Weed Management. Pacific Nut Producers. Vol 27. N3 March 2021. Moretti, M. L. Author & Presenter, American Society of Horticulture Science, "Thermal and mechanical weed control in organic highbush blueberry," Orlando, FL. National, Accepted. (August 13, 2020). Moretti, M. L. Author & Presenter, Weed Science Society of America, "Weed control in highbush blueberry," Maui, HI. National, Accepted. (March 4, 2020). Moretti, M. L. Author & Presenter*, California Weed Science Society, "Under-Vine Mechanical Weed Control.," Monterey, CA. Regional, Invited. (January 23, 2020). What do you plan to do during the next reporting period to accomplish the goals?Obj1. Continue the long-term study proposed on Obj 1.1 for an additional two seasons. Initiate obj 2 projects after hazelnut harvest during the fall of 2021.

Impacts
What was accomplished under these goals? Obj 1.1 - Two large-scale field studies were initiated in 2021. We have identified electric weed control (EWC) power required to control effectively Italian ryegrass in hazelnut orchards. Inflorescence number and biomass data were also collected to estimate the impact of EWC on reproductive output. Plant DNA is now being analyzed to identify possible mutations conferring herbicide resistance. We will then be able to infer the effect of EWC on the survival and reproductive ability of resistant ryegrass in commercial settings. Obj 1.2 A field study was established on OSU's Lewis Brown Research Farm. Treatments include nontreated, tillage, EWC at high power after removing tree suckers, EWC at low power after removing tree suckers, and EWC at high and low power applied to tree suckers. These six treatments are replicated six times and include two hazelnut varieties of economic importance to Oregon. Objectives 2.1 and 2.2: Work on these will begin in fall 2021.

Publications