Innovative and Affordable Methods of Managing Weeds in Strawberry Production

Final report for FNE18-887

Project Type: Farmer
Funds awarded in 2018: $10,399.00
Projected End Date: 02/28/2019
Grant Recipient: Burley Berries and Blooms
Region: Northeast
State: New York
Project Leader:
Megan Burley
Burley Berries and Blooms
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Project Information

Summary:

This project’s objective was to trial several (6) weed management techniques in a matted row strawberry system including Integrated Weed Management (cultivation and herbicides), Cultivating, Mulching (middle row with either Industrial Hemp or Landscape Fabric), Herbicides, and Particle Weeding.  Particle weeding is a new method developed by Sam Wortman, University of Nebraska, which uses air-propelled abrasive grits to kill small weeds within a crop row.  For this project we built a trial size air-propelled abrasive grits machine using an air compressor, grit hopper and meter, and nozzle. At the end of the trial in comparison to the control (which had 10% survivability of strawberry plants) the best method was Integrated Weed Management with a survival rate of 99% for the strawberry plant and and weed percentage rate of 2% and a cost of $30 per acre.  Second place was mechanical cultivation, more friendly to organic production, at 20% weed cover in week 8 and a cost of $5 per acre. 

More research should be done on the Industrial Hemp mulch (cost of $2.96/ft2 and 30% weeds at 8 weeks) , although costly, if produced locally in the North East, we believe there is some great potential to utilize this product for weed management in other types of organic production. 

The research results were disseminated to 15 growers in western NY via a field day.

You can view a video overview of our project here: https://spark.adobe.com/video/t3SYzCZS5GcAW?fbclid=IwAR2N_hcxyQTjpqMoSwE75e5MezTPm_S1EEKp85S5abwuEXW3fp2qiqkBEcM 

Project Objectives:

This project’s objective was to trial several weed management techniques in a matted row strawberry system including mulching (industrial hemp and landscape fabric), cultivating, integrated weed management (cultivation and herbicides), and particle weeding. Particle weeding is a new method developed by Sam Wortman, University of Nebraska, which uses air-propelled abrasive grits to kill small weeds within a crop row.

Introduction:

Managing weeds in matted row strawberry production is a costly challenge. Partly because strawberries are a perennial plant and weeds with similar life cycles often become established as plantings get older.  Herbicides are somewhat limited in matted row strawberries in western NY as they are a minor crop and the potential for injury to strawberries is high. Effective weed management during the first year is imperative to improve yield for the fruiting years (years 2-4).  One of the main methods for weed control in matted row strawberry plantings is cultivation or pulling weeds by hand.  Although strawberries are a high value crop the cost of labor for cultivation and hand pulling continues to increase reducing the profitability of this crop (Dec 31, 2017 NYS minimum wage increases to $10.40). 
In western NY a significant amount of the strawberries are grown using the matted row system.  This is because many of these farmers grow crops near the main tourism areas in the state including Niagara Falls and Letchworth State Park and are engaging the consumer in agri-tourism activities.  The matted-row system has a relatively low cost of establishment and is easier to maintain when consumers are entering a field, whereas in plasti-culture there are more chances for this mulch to be ripped or torn.  Many large scale growers have switched to plasiti-culture for strawberry production which utilizes raised beds, black plastic mulch, trickle irrigation, high-density plantings, and floating row covers which increases capital inputs by $7,000 per acre +/- (Source: The Mid-Atlantic Berry Guide).  Although this system has the potential to give high yields in longer growing seasons, lower yields are common in cooler areas (zones 6a and cooler, most of western NY is in zone 5 or 6).  (Source: The Mid-Atlantic Berry Guide).  Many of the strawberry producers in western NY are beginning farmers, most utilizing organic growing practices that want to limit the use of plastic, who are continually increasing production but continue to struggle with weed management.

There are several fact sheets that have been developed for weed management in matted-row strawberry systems but many of the processes have not been tested in western NY. Cornell’s Pest management Guidelines for Berry Crops includes several weed management strategies that would be useful for growers in western NY. For farmers to see a field trial to gauge the impacts on weeds to potentially be adopted as a new growing practice in the future.  Particle Weeding is a new idea being utilized in Nebraska for weed management in organic vegetable and field crops.  Several vegetable crops have been used for testing this method but there is limited research on how it may be utilized in strawberry production.  Northeast SARE funded a project several years ago related to weed management utilizing landscape fabric.  This project includes these materials to use as a comparison.  Industrial hemp is being grown in western NY and there is currently a limited market for this crop.  Industrial hemp mulch is said to provide a dryer surface layer, which may help reduce conditions for weed growth.  There has been limited research on industrial hemp mulch used in a matted-row strawberry system.

Cooperators

Click linked name(s) to expand
  • Dr. Darcy Telenko - Technical Advisor (Educator and Researcher)

Research

Materials and methods:

For this project we implemented 6 treatments with 3 replications of each. Each treatment was the width of one row (4ft) and 65 ft long and the replications were spread throughout the field for land variability. The remainder of the rows were left untreated for comparison.

Treatments:

  1. Integrated weed management following chart 7.4.2 in the Cornell Pest Management Guidelines for Berry Crops for herbicide recommendations followed by biweekly cultivating. Cornell-Guidelines-Weed-Management-Chart
  2. Bi-weekly cultivation
  3. Herbicide only following the herbicide recommendations for planting year on chart 7.4.2 in the Cornell Pest Management Guidelines for Berry Crops.Cornell-Guidelines-Weed-Management-Chart
  4. Landscape fabric placed in row middles at planting.
  5. Industrial hemp mulch applied in row middles at planting.
  6. Particle weeding (weed blasting). A physical form of weed control that uses air propelled abrasive grits to kill small weeds within a crop row. Any small, gritty material can be used in abrasive-weeding, but for this project we wish to use cornmeal. Since previous research has found that one blast of particles (cornmeal or greensand fertilizer) reduced weed seedling biomass by 95-100% based on weed type.  This weeding method was especially useful in treating palmer amaranth and green foxtail.  Abrasive grits will be applied between the rows via compressed air (100 PSI) by hand using a machine created with a portable air-compressor and a hand-held siphon grit applicator, both of these can be found at our local hardware store.  See pictures for details on the two models we built: 
    Prototype 1
    Prototype 2

     
Research results and discussion:

For each plot we measured weed type and percent cover every other week for 8 weeks. Below you will find the information collected on the original methods for each treatment.  All plots were prepped the same.  The strawberries were planted into a field that in 2017 had roundup ready soybeans.  The field was moldboard plowed and rototilled following a 20 day wait of roundup.  Simplified version can be found via this chart: SARE-Chart-for-weed-management1

  1. Integrated weed management following chart 7.4.2 in the Cornell Pest Management Guidelines for Berry Crops for herbicide recommendations followed by biweekly cultivating. Cost per acre: $30 ($25.34/acre herbicide cost, $5/acre fuel cost)
    1.   After planting Prowl H2O was used as a post plant herbicide application (about 1/2 inch of rain followed 5 hours after the herbicide application) 
    2. We waited to spray until weed seedlings were present before cultivating which was about 4 weeks (the spring was abnormally dry).  Weeds present included spurry, shepherds purse, and amaranth (pigweed) at about 2% coverage per plot
    3. Week 4 we cultivated and continued to cultivate every other week (2% weed coverage at each time of cultivation weed type included: pigweed
    4. The weed management chart in the Cornell Guidelines called for a spray of fusilade for perennial grasses and devrinol.  We did not spray these as there was not sign of grasses in these plots.  We believe that since we had a dry year and had the right amount of rainfall following the application of Prowl H2O it did a good job of continuing to control the grasses
    5. Bi-Weekly cultivation was used in the follow weeks for 8 weeks 
    6. This method at the gave us the best weed management results at the conclusion of the project 
  2. Bi-Weekly Cultivation. Cost ($5/acre fuel cost)
    1. 2 weeks after planting we began the Bi-Weekly Cultivation treatment
    2. Weed percentage present at first cultivation was 5% cover and weeds identified included Fox Tail, Pig Weed, Lambsquarter, Spurry, and maple trees
    3. Bi-Weekly cultivation continued for 8 weeks
    4. by the end of the trial weed percentage in this treatment was about 20% making it the 2nd most effective treatment
  3. Herbicide only following the herbicide recommendations for planting year on chart 7.4.2 in the Cornell Pest Management Guidelines for Berry Crops. ($25/acre herbicide cost)
    1. Prowl H2O was sprayed following planting with 1/2inch rain.
    2. 4 weeks later we noticed about 2% weed coverage including pig weed and spurry
    3. We  missed the week in mid-June to spray the Fusilade and Devrinol due to the face we were in the midst of strawberry season
    4. Week 6 we noticed grasses coming into the plots and figured it was because we did not spray the extra herbicdes
    5. At 8 weeks there was 50% weed coverage with fall annual weeds (fall panicum, pigweed, chickweed, and quack grass)
    6. This treatment would have probably been more successful had we sprayed grass herbicides at the proper time.
  4. Landscape fabric placed in row middles at planting. ($1.57/sqft about $10,000/acre)
    1. For this treatment we used 4ft landscape fabric and covered the rows 2 weeks after planting.  We burned a hole down the middle of the 65 foot landscape fabric treatment area with a torch.  Since we grow using a matted row system the goal was to train the runners to stay between the row fabric
    2. At week 4 weed cover was about 40% and most weeds were grasses.
    3. At week 5 we pulled the grass weeds as they were at 60% coverage and we didn’t want them to kill the strawberry plants
    4. This treatment may have worked better if Prowel H2O was sprayed originally. Landscape fabric was more costly than cultivating but about equal to cost of herbicides.
  5. Industrial hemp mulch applied in row middles at planting.  Total Cost of Fabric: $2.96/sqft about $30,000/acre
    1. Industrial Hemp mulch was purchased from a company in CA as there was no local producers of this product.
    2. The mulch was applied at 4 weeks after planting due to shipping.  There was already 20% weed coverage (pigweed, spurry, lambquarter, grasses)in these areas so we decided to cultivate before we applied the mulch to start with a weed free area. 
    3. At week 6 weed control looked great about 5% weed coverage
    4. At week 8 there was a lot of grass seed germination on top of the fabric from other plots.  Weed coverage was about 30%.
    5. By week 10 grass coverage was significant about 60%.
    6. This may be an effective weed management strategy if removed from area with lots of weeds that have propagate via seeds.  Since several of our Industrial Hemp mulch plots we near the control plots.  I do think more research would show that this may be a great alternative for plastic mulch in vegetable production
  6. Particle weeding (weed blasting). A physical form of weed control that uses air propelled abrasive grits to kill small weeds within a crop row. Any small, gritty material can be used in abrasive-weeding.  Total Cost: $25/acre;initial capital costs not included which is about $600 
    1. For this weed management technique we purchased a gas run air compressor and a small sand blaster.  We used 3 different sizes of grit (220, 180, and corn meal).  We trialed all three sizes of the grit in the sand blaster with no luck of showing physical damage to the weeds.  The weeds were in seedling stage. Depending on the size of grit it kept getting stuck in the tubes before actually leaving the sand blaster.  We tried several different solutions including shortening the distance the grit had to travel in the tubes but had not luck. We decided to purchase another sand blaster (Better quality and more pressure).  Used the same three types of grit and could not show any difference and grit continued to get caught in the tube of the blaster.
    2. Since we could not create a decent prototype we decided to blast one plot and see if it would injure the weeds enough to set them back. It did not.  By week 8 we had about 80% weed coverage.  
    3. There is other research that proves this method works but we did not have success on building a functioning prototype
    4. The cost to build this machine was $500 for the gas air compressor, $100 for Air blaster, and $25 for grit. For the 2nd prototype the air blaster price increase to $200.
  7. Control
    1. By week 8 the control plots were 90% covered in annual/perennial grasses.  The survivabilty of the strawberry plants was 10%.
Research conclusions:

This project’s objective was to trial several weed management techniques in a matted row strawberry system including mulching (industrial hemp and landscape fabric), cultivating, integrated weed management (cultivation and herbicides), and particle weeding. 

The most effective method for weed management for our project in matted row strawberry production was the integrated weed management trial.  A little more costly than just mechanical cultivation and not an effective treatment method for a grower who is certified organic but weed management was significant.  Next year we plan to monitor the yields based on treatment areas to see if there is any significant difference.  I would eventually like to try industrial hemp mulch in a vegetable production system and see the impact it may have for future weed management in fresh market vegetables. With the new realization of weed management methods measured on our farm our strawberry yield should increase significantly and provide a more customer friendly environment for our you pick customers. 

Participation Summary
1 Farmer participating in research

Education & Outreach Activities and Participation Summary

2 Consultations
1 On-farm demonstrations
2 Published press articles, newsletters
1 Tours
3 Webinars / talks / presentations
1 Workshop field days

Participation Summary

120 Farmers
50 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

At the beginning of the project a newletter article was written for the Wyoming County Ag News with a readership of 120 farmers/homesteaders.  A press release was also sent to several media sources but it is unknown if they picked it up for printing. We plan to present at the NYS Vegetable EXPO in Jan 2019.  On Oct 1st we  hosted our on farm field day to discuss the trial with local growers with a newsletter article to following the event.  Participants review our results and explored the weeds managed within our trial.

Learning Outcomes

15 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

The main farm who gained knowledge through this project was our farm. We definitely plan on adopting practices we used in this field trial as we saw a huge difference in plant vigor using the integrated pest management method

Project Outcomes

Project outcomes:

Improved quality of customer experience due to lack of weeds in our you pick field.  Hope for increase in yield for following year.  This project has made us realize what is the best weed management method and also gave us the ability to really analyze the weeds that germinate during the season.  We also have a better guess on the costs of production for multiple treatments. 

Assessment of Project Approach and Areas of Further Study:

Key’s to project success:

  1. Time management and cultivation timing.  This project made us cultivate on a more timely routine which really benefited the growth of the strawberries.
  2. Having rain right after spraying the Prowl H2O was perfect timing.  Whether this would happen again is unknown.

Revisions in methodology:

  1. building of the weed blaster.  Do do this again it would make sense to have the original creator of this idea to help build a prototype.  This method has proven to work in vegetable production but we couldn’t get the right prototype together and the weeds continued to grow so the size of the weeds may have been the determining factor.
  2. Move the control plots to an area not near the industrial hemp fabric as the weed seeds germinated on top of the hemp mulch from the weeds in the control trials.

Why we will continue to use Integrated Weed Mangement:

The weed control was great. With timely cultivation and herbicide application we hope to see a gain in yield next year as well.  Also, our customers will be much happier picking in a weed free field. 

 

Who would benefit from this knowledge:

Strawberry growers in the North East and potentially organic vegetable farmers looking for weed management strategies as I think there is potential to try a trial with industrial hemp mulch in fresh market vegetable production. 

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.