Design, Testing and Construction Education of a Post and Wire Support Structure for Insect Exclusion Netting on Field Grown Berries

Final report for FNE20-963

Project Type: Farmer
Funds awarded in 2020: $15,000.00
Projected End Date: 05/31/2023
Grant Recipient: The Berry Patch of Stone WAll Hill Farm, LLC
Region: Northeast
State: New York
Project Leader:
Dale Ila Riggs
The Berry Patch of Stone Wall Hill Farm, LLC
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Project Information


Berry growers in the Northeast continue to battle Spotted Wing Drosophila (SWD), an invasive pest that has permanently altered production systems for berry growers.  A previous SARE Farmer Grant that I received demonstrated that exclusion netting is a highly successful method for managing this pest.  As growers come to the realization that SWD is here to stay, more growers are interested in using exclusion netting.  A major stumbling block for acceptance of this technique is the lack of information regarding what type of support structures to use.  When this project was first visualized, there were not any commercial companies providing support structures and there was a lack of a tested design and plans for growers to construct their own structures. After this proposal was awarded, one commercial company in Canada introduced a modified version of a shade support structure that they felt would work as a netting support structure. In this project we built and tested a support system that compared using wooden posts and cable to one using metal posts and cable for growers to see and learn how to construct.  Both systems worked well as a support structure but the metal system is much easier to install and will last for the life of the planting.  We conducted field days, had personal consultations, participated in webinars and virtual presentations at grower conferences to educate growers about the systems.  Videos were produced and posted to the UVM Ag Engineering YouTube channel to teach growers the construction process for building a structure, how to cover it, and how to store the netting for the winter.   Lastly, conversations were initiated with NRCS and our local Congressman to try to determine if there is a way to start the approval process for cost-sharing assistance for exclusion netting systems.

Project Objectives:

This project seeks to:

  1. Test two versions (wood post and cable and metal post and cable) of a newly available commercial support structure for insect exclusion netting, made from materials that growers can readily buy through building supply or farm supply companies or through the company that is now offering the structures.
  2. Teach growers how to construct their own support structures through on-farm field days and YouTube videos.
  3. Determine the costs of materials and labor involved to build and cover a half acre planting so growers can determine the investment needed to build their own structure.
  4. Open a conversation with NRCS to start the process of adding exclusion netting support structures to the list of approved practices for EQIP cost share programs.

SWD has forever changed berry production throughout the world.  In the Northeast, many small-scale berry growers have torn out plantings of fall raspberries and blueberries because they don’t want to spray every five to seven days to manage this pest.  My previous SARE Farmer Grant clearly demonstrated that 80 gram exclusion netting, manufactured by Tek-Knit Industries in Quebec is highly effective as a management method.  In my work, I adapted an existing bird netting support structure, made from old high tunnel hoops, to support the netting.  I have now successfully worked with this prototype for six years.  But it is a prototype that I created with materials that I had on hand.  It was not intended to be a final design for other commercial growers to use as a support structure. 

The problem is that most growers, especially if they are not growers used to using tunnels for season extension, are unfamiliar with using a hoop system for a support structure or do not feel that a hoop structure fits into their production and marketing system.  The hoop system has inherent liability problems for people that want to use it for Pick-your-own marketing, and since the hoops are not made in custom widths for lining up in blueberry rows, the system is not friendly for equipment used for maintenance during the growing season.  I have tried to get different greenhouse manufacturing companies interested in designing and manufacturing a structure, to no avail.  Interest in using exclusion netting is growing but the lack of a tested support structure that growers can easily access is hindering adoption of this highly effective system. 

To start to address this problem, in 2018, as a test and demonstration, I constructed 2 rows of a post and wire system that I integrated into my existing hoop support system.  In an effort to keep it simple, inexpensive, and made of materials that everyone can access, I used construction quality PVC pipe and nylon high tensile wire that I had on hand.  I worked informally with Chris Callahan, the Extension Ag Engineer for the University of Vermont. Chris determined what size pipe would be necessary to support the weight of rain saturated netting, and suggested fastening systems for the wire supports.  The system was workable, improving the ability to use equipment between rows, and having a continuously high ceiling in that part of the planting improved the atmosphere and reduced liability issues for pick your own customers.  However, this small demonstration also highlighted unacceptable deficiencies of this approach.   While the PVC pipe worked great for the support structure in the second (interior) row, it is not strong enough to use in the first (outer) row.  The wind resistance of the netting blowing against the supports pushed them inward so they were no longer straight.  The position of the wire that ran through PVC end caps on the top of the posts needs to be changed, and a heavier duty wire anchoring system, perhaps using earth anchors, needs to be used to ensure that the wire stays taut and does not sag.  Cross wires need to be added to the system (we just used wires lengthwise) to avoid sagging of the netting between rows.  Lastly, while the PVC pipe appears to be very smooth to avoid abrasion issues, I found that was not the case, and some holes formed in the netting due to abrasion from the netting moving back and forth across the PVC end caps.  Netting on the hoop support structure has never had these issues.

My solution is to work with Chris to design and test an engineered system that uses wooden posts for the perimeter footprint of the planting, PVC pipe for the interior supports, integrate cross wires into the structure, and create a heavier duty anchoring system.    Most importantly, we want to teach other growers, through field days and by creating YouTube videos, how to construct similar systems from materials that are readily available from any building materials supplier, so they can build their own support structures.

Additionally, NRCS has expressed interest in cost sharing for exclusion netting systems but cannot proceed on getting practice approval without a set of engineered plans for growers to follow and for staff to approve.  Now that a commercial support system is available, I want to open a conversation with NRCS to learn how to get a support structure to qualify for cost-share assistance.

Since this project was awarded funding, I found a commercial company, Gintec Shade Technologies of Ontario, Canada, that wanted to cooperate on this project.  They already make shade support structures for ginseng growers and are interested in making their structures usable for berry growers that want to move to using insect exclusion netting.  They offer support systems using wood posts and airline cable as well as metal posts and airline cables.  In speaking with Chris Callahan, my technical advisor, we felt it was prudent and more time effective to test the Gintec structures rather than start entirely from scratch.  Their systems include all the features that we wanted to include (a heavy duty anchoring system and cross wires) and they are engineered to withstand 80 mph winds - an important feature for possible approval by NRCS.

Description of farm operation:

I am a first generation farmer, starting The Berry Patch from a worn out corn field in 1995, after purchasing 91 acres (15 tillable) one mile from my house in Stephentown . What was supposed to be a part-time berry farm grew into a diversified berry, vegetable, and cut flower farm over the years. I started selling pick your own strawberries from 1/3 acre in 1997, while I waited for my initial raspberry and blueberry plantings to mature. I grew the business every year. I added some vegetable crops to the mix and opened my farm store in 1999. I added a second hand high tunnel in the early 2000's, and started opening my farm store a little earlier in the summer each year. In 2003, I purchased the adjacent 114 acres. In 2007, I built my first greenhouse, allowing me to produce tomatoes even earlier in the year. Originally, I just sold through our farm store, but the financial meltdown of 2008 taught me that I needed to diversify my markets. In 2009, I was able to start selling in the Troy Waterfront Farmers Market. In 2011, restaurants in the Berkshires started to request our berries so I started a restaurant route as well. By 2014, I was producing on 9 acres, had 10 employees, three marketing channels, and owned 210 acres of land with one greenhouse and 4 unheated tunnels. My husband took early retirement in 2015 to help manage the farm. In 2018, we became debt-free and have been down-sizing since to attempt to have some time to do other activities and to have time to indulge our passion for travel. After losing 40% of my blueberry crop to Spotted Wing Drosophila in 2012, and having to spray 6 nights a week for SWD in 2013, I received a SARE Farmer grant in 2014 to experiment with using exclusion netting to manage SWD in blueberries. That project was a great success and I have been using exclusion netting ever since. Each year since that initial project, I have improved the netting support structure and the techniques for deploying netting in the spring, managing the netting during the summer, and storing the netting during the winter. After multiple years of using exclusion netting, and giving more presentations than I can remember, it became abundantly clear that the next step for helping other growers use this technology would be to use my experience and personal research with alternative support structure options to create a "recommended" support structure for the netting.


Click linked name(s) to expand/collapse or show everyone's info
  • Christopher Callahan - Technical Advisor
  • Laura Griffen McDermott
  • Gregory Loeb


Materials and methods:

Research Activities in 2020

Working with Gintec Shade Technologies (referred to as Gintec for the rest of this report), we purchased enough materials to construct a permanent support structure over our half acre commercial planting of blueberries.  We purchased supplies to use wood posts and cable on 40% of the planting and metal posts and cables on 60% of the planting.  After my proposal was written and approved, Tek-Knit Industries introduced their new 85 gram netting.  It is a netting that I played an integral part in designing and encouraging them to produce.  It is designed to reduce the likelihood of long tears in the netting that may happen when abrasion of branches or some other event causes small holes to form and are then expanded by wind events.  Another innovation that I played a part in was the introduction of zippered panels. Panels of sewn netting with zippers on each side of the netting were purchased from Tek-Knit Industries of Montreal, Quebec.  The zippers were sewn into the netting by Gintec.  This negated the need for my past system of joining panels using a wiggle wire system attached to greenhouse purlins (straight pipes) to join panels.  That system has worked extremely well for us but Tek-Knit decided to experiment with zippered panels to make installation of netting that much easier.  The zippered panels are also cheaper for growers than purchasing greenhouse purlins at $1.00 per linear foot plus wire lock channel and wiggle wire.

In late May, Chris and I worked together to lay out and flag spots for each wooden post and metal post that would be installed. That first required us to square each corner through triangulation, and then measure down the length of the rows and across rows to flag each individual spot for post installation. To make the process more efficient, we used pre-measured pipes to ensure that we were following the same dimensions throughout the planting.

Holes for the wooden posts were made using rented single person and two person augers. Because of rocks in our soil, the augers were problematic, difficult, and dangerous to use. We then rented a “Ground Hog” hydraulically operated auger which was much safer and more efficient to use. After spending two days fighting with single person and two person augers to try to make holes for 36 wooden posts, we installed over 100 earth anchors in one afternoon with the “Ground Hog”. A special adapter had to be made for the augers that would fit on the hexagonal shaft on the auger and over the metal loop on the earth anchor but a local machine shop was able to make one for us out of heavy duty steel.

Wooden posts and metal posts were distributed to their respective locations throughout the planting. The stainless steel airline cable that was supplied by Gintec was run down the length of each set of posts, posts were set in place without yet working to get them level and cables were hand tightened temporarily. The same process was used to then run the crossways cables. Cables were attached on one end with a “dead man” fastener, and on the other end with a two bolt cable clamp. After all cables were set in place, we then used come-alongs and cable winches (provided by Gintec) to tighten each cable from the end that had the cable clamp. Each post was individually leveled in two directions and the cable winches were used to tighten the cable. The person on the deadman end of the cable would say when the earth anchor on that end started to move up, indicating it was time to stop winching the cable. The cable winches provided by Gintec were much easier and safer to use than the come-alongs obtained at hardware and tractor supply stores. Once the cables were tight, they were anchored in place with wire clamps placed on both sides of each wooden post. On the metal posts, the cables were anchored in place with J-clamps provided by Gintec.

We had wanted to have a construction field day during the actual installation of the posts but due to Covid-19 restrictions and lock-downs, we were unable to hold such an event. 

Sewn panels of 85 gram netting from Tek-Knit were installed in two sessions. Sewn panels were numbered by Gintec (who did the industrial sewing) so that the right pieces would be joined together. Six panels were used to cover our half acre planting. The netting was pulled from one end to the other via rope. One person fed the netting from a suspended roll of netting and up over the first cable. Rope was tied to the end of the roll, thrown up over each cross cable and pulled the length of the planting. After putting up the first panel of netting, we fabricated a T out of PVC pipe that we used to help keep the netting above the cables as we pulled with the rope. It reduced the amount of friction of the netting on the cable and made the netting much easier to pull. Netting was fastened to the lengthwise cables with hog rings supplied by Gintec. Initially we just installed 2 hog rings per 15 foot section to hold the netting in place. Pieces of netting were then connected using the zippers sewn onto the edges of the panels. We had a few sections where the zippers were a bit difficult to pull but we were able to get all sections zipped together to cover the planting. Upon dismantling in the fall, I discovered that there were areas where the netting was also in the zipper channel, similar to a jacket zipper being difficult to pull when the jacket flap is entangled with the zipper pull. I believe this was the reason for some areas being difficult to zipper together.

We had intended to bury the ends of the netting under soil at the two ends, but we did not stretch the netting tight enough to provide enough extra netting at the ends to do that. We used the same system that we have used for the last 5 years – a 1” x 6” hemlock board with wire lock channel attached. We fastened the baseboards to the shafts of the earth anchors with pipe straps. We then used wiggle wire to attach the netting at the ends. We use 2 layers of strips of old greenhouse plastic between the netting and the wiggle wire to protect the netting from abrasion. We used a continuous strip of sand to bury the netting along the long edges of the planting. We re-inserted our vestibule entry that we have used for the last 6 years to finish securing the planting.  The vestibule is a key feature of my exclusion netting systems.  It's a double door entryway so that people unzip the outer doorway, enter the vestibule, close up door number 1, and then unzip door number 2 to enter the planting, zipping up door number 2 upon entry to the planting.  It reduces the human error aspect of accidentally allowing SWD to enter because a door is not closed completely or may be blown open by the wind.  We had planned to make a larger vestibule for this year but ran out of time.  That is part of the plans for 2021.

We finished securing the netting on the planting on June 30th, 21 days after the first SWD adult was found in traps in a near by hedgerow at The Berry Patch and seven days before our first harvest. We harvested berries for commercial sale until September 3rd. During that time, 225 berries per week were harvested (25 berries from each of nine zones) and sent to Greg Loeb’s lab at Cornell Agri-Tech to determine larval infestation. No fruit infestation were found until the very last sample was collected on August 31st, when two larvae were detected from 225 berries. That results in an infestation rate of less than 1/10th of one percent over the season.

During each installation event, video and/or photographs were taken of all activities and will be edited at a later date to create You-Tube videos of each aspect of construction and installation. 

A twilight meeting was held on October 14, 2020 to discuss the entire project, share lessons learned from the new design, and discuss economics of the new design.

I have started initial discussions with NRCS regarding how to initiate the process to obtain approval for cost-sharing assistance for exclusion netting systems for commercial farms.  Based on the previous work that I have done with exclusion netting and previous conversations with NRCS they have included insect exclusion netting as an allowed expense in pest management systems but they have not included support structures for the netting.  They also have an unrealistically low cost for the exclusion netting in their practices so I have started working to document the actual costs of the netting, including the improvements with the 85 gram netting and zippered panels.

Research Activities 2021

In the second year of the project, we did a spring inspection of the structure in May and had to re-tighten several cables that had loosened over the winter.  We re-deployed the netting from its winter storage on the support structure cables in the middle of June.  We added additional netting to the west end of the planting to extend the length of the netting and make it a bit looser to reduce the likelihood of abrasion on the end posts.  We added caps to the tops of the metal posts that were supposed to reduce sharp edges coming in contact with the netting but decided to also add bubble wrap caps to the tops of all the metal posts as the post caps still had some sharp edges that could damage the material..

Based on our experiences with voles and other rodents chewing through the fabric at ground level in 2020, we went back to our old system of using a perimeter board with greenhouse wire lock channel and wiggle wire to anchor the netting at the bottom.  We used 1" x 8" boards, rather than 1" x 6" boards to get the netting further away from the grass and other ground cover vegetation that is around the perimeter.  Our observations from 2020 showed us that when a board is in place, the voles will burrow underneath the board, rather than chew through the netting.  This greatly reduced the amount of damage during the summer.

We repaired small holes in the netting by using UV resistant thread to sew the holes closed, or by using Waterproof gorilla tape on the outside of the netting hole and regular gorilla tape on the inside of the netting.  This repair system worked well because the outside piece of tape sticks to the inside piece of tape and holds it in place.  The gorilla tape adhesive appeared to hold up to the elements better than the adhesive on standard duct tape.

The person we hire to do handyman work built a much larger vestibule so that large groups of people can enter the planting at one time.  Unfortunately, he was a bit late in building it, and with the blueberry crop ripening a full ten days earlier than we have ever experienced before, we were not able to place the vestibule before the planting had to be sealed up in netting.  The vestibule is currently situated about 30 feet away from the planting so we intend to get that in place in the spring of 2022 to be covered in June of 2022.

The Eastern New York Commercial Horticulture Program collected 225 berries each week (25 berries in each of 9 samples) every week through the harvest season.  The berries were sent overnight mail to Greg Loeb's lab at Cornell AgriTech in Geneva NY on the day they were harvested.  The lab evaluated them underneath microscopes and by using a saltwater flotation method to determine if there were any SWD eggs or larvae present.

We harvested blueberries from June 30 to September 10.  Zero larvae were found during our 10 week harvest season.

We held a field day on October 5 for growers and our Congressman, Antonio Delgado, came for a visit on October 11 to learn about the blueberry system.  We also had several growers make individual appointments to see and examine the system.

We unzipped the panels and wrapped them in UV resistant pallet wrap for winter storage in early November

During the late fall and early winter, Chris produced 4 videos of the construction process.  They can be found on his UVM Ag Engineering YouTube channel.

Research activities 2022

Four more installations of netting were constructed for blueberries in 2022 - 2 in New Hampshire, 1 in Vermont, and 1 in New York.  In 2023, a structure will be built in Rhode Island for strawberries, one for blueberries in Pennsylvania, one for raspberries in Pennsylvania, two for blueberries in Ohio, and one in Wisconsin for raspberries.  

Chris created a SWD blog that summarizes the work we’ve been doing and created a 5th video;

More people have come to The Berry Patch to view the structure and emailed with questions;

I am now on a public radio gardening call-in show every other week from March through November so I have a forum for discussing the netting work when appropriate questions come up;

I was on a Connecticut Public Radio gardening show to discuss the work. 

Scientia Science Diffusion journal published an article about the work in their worldwide journal;

And we had another year of zero percent infestation and super productive bushes!

Research results and discussion:

In 2020, no SWD larvae were found until the very last sampling on August 31, when two larvae were found in 225 berries, resulting in an infestation rate of 0.001 % over the course of the entire season.  In 2021, no SWD larvae were found during any sampling, resulting in 0.000 % infestation.  The same occurred in 2022.  That was the fourth time in 9 years of using exclusion netting that not one single larvae was found in our blueberry crop.

In the past, we have sold over 99% of our crop through our retail store, farmers markets, and wholesale to a food coop.  Due to Covid, we did not open our farm store in 2020 or 2021, so we marketed some of our berries through Pick Your Own.  Many growers are skeptical about PYO customers being amenable to using a netting system.  We found the exact opposite to be true.  PYO customers absolutely loved the netting system.  Not one single person had a negative reaction to the netting system.  We received numerous comments about what a wonderful picking environment it provided and that they felt like they were in "blueberry heaven".  Customers also loved the fact that we were not spraying our berries because we were using the netting system.

The improved support structure created a wonderful environment for pickers.  It is taller than my old hoop system so there was more room for hot air to rise, making picking more comfortable.  However, it is still hot inside the netting on a hot day as the netting diffuses the wind and does not allow for evaporative cooling of pickers.  The netting has an 11% shade factor, enough that it can make the planting more comfortable to work in on bright sunny days that are not too hot.  With fewer posts and the posts being entirely vertical, there were fewer issues with PYO customers potentially being injured from walking into a post.  Having a tall structure, designed for movement inside, allowed us to offer PYO to the general public, something we would not have felt comfortable doing before.  That allowed us to sell more blueberries during the pandemic than we would have been able to otherwise, improving our profitability.

Being the first people to build a support structure like this involved several challenges.  There are too many fine points to detail so the main points are summarized below:

Growers wishing to build such a structure are advised to do so in the fall or early spring, just after the ground thaws, rather than in May and June when the plants are in active growth.  Ideally, for new plantings, a structure would be built before blueberry bushes are planted in the ground.

Making sure that one spends the time to have square corners is important.  One can use a mason's line and layout stakes and flags.  Using a transit is not necessary but if one is available, it will save time.

Anchor adapters to drive the anchors will most likely need to be fabricated at a local machine shop.  We found the machine called a "Ground Hog" to be far more user friendly and efficient for driving anchors than any post hole digger.  One will need to measure the size of the shaft to use for driving the anchors and use those measurements for the anchor adaptor to be manufactured.

A helical style ground anchor will be more difficult to drive in rocky soil.  If the site has rocky soil, one should request a different style of ground anchor.

Cable winches with a rotating handle and chain, rather than a come-a-long with wire are far easier, far safer, and far more time efficient to use for tightening the cables.

Sharp ends of cable clamps and cut ends of cable need to be wrapped in duct tape or cushioning material to prevent damage to the netting.  These coverings need to be inspected each year.  

The tops of all posts should be covered with bubble wrap or a soft material like felt and duct taped to the posts to protect the netting from abrasion and sharp edges.

When installing the netting, unroll each panel fully and center the panel on the structure before attaching them to the cable.  Use a PVC "T" to help hold the netting up off the cables while pulling the cable the length of the planting.  It will protect the netting from possible abrasion against the cables.

In the rows that will be unzipped at the end of the season and pushed back to one cable to store for the winter, carabiners should be used to attach the  netting to the cables, rather than hog rings.  Hog rings are fine to use on the "winter rows" - the cables where the netting is not unzipped and where it is stored for the winter.

Remember to flush birds out of the enclosure prior to zipping up all the netting panels each spring.  You may also need to remove nests to ensure that all birds leave.

It will take longer to construct the structure when the people working on it have little construction experience.  People without construction skills can do the installation but it will take longer.  We estimate that three people with basic construction skills can build a half acre structure in 40 hours - from layout to driving anchors to setting posts to covering with netting.

Two people can re-deploy netting in the spring on a half acre planting in 8 hours.  If the netting is not attached to a baseboard with a wiggle wire system, it will take less time.  However, attachment to a baseboard system is highly recommended.  Sand bags, pipes, and lumber are no match for thunderstorm or straight line winds.  Two people can put the netting into winter storage on a half acre planting in 6 hours.

Installing metal posts for a structure is far faster than installing wooden posts.  The higher price for metal posts is more than offset by the much faster labor costs for installation and greatly increased longevity of metal posts.  The metal posts are there for the life of the planting.  They are also designed to be easier to replace should a post failure occur.  If a wood post on the perimeter fails, the cable on the entire row needs to be redone as the cable goes through every wood post.  If a metal post fails, it is easy to replace just the individual metal post as it sits on top of an anchor, it is not buried in the ground.  The cable does not need to be redone because it is attached to the side of the metal post, making it easy to remove from the post and attach to a new metal post.

The support structure and netting held up through three tropical storms in ten days.  Winds were between 40 and 60 mph during those storms.  One corner post created a hole in the netting during the third tropical storm.  The new design of netting prevented the hole from becoming too large.  It was approximately 18 inches in length and I was able to repair it using a standard needle and thread to sew the 2 sides of the tear back together.  The system also came through an accumulating hailstorm without any problems.  In one area where we had not anchored the netting to the cable with enough hog rings, the netting stretched and sagged about 2 feet.  It had eight inches of hail in it that lasted for more than 24 hours.  There was no sign of stress on the structure, nor on the netting.

The materials for this half acre structure cost just short of $12,000.  The netting will last for 5-10 years, the metal structure will last forever.  Depreciating the costs over 5 years, with a 5% interest rate results in a yearly cost of $2500 for the five years.  When the netting needs to be replaced, the yearly cost will be less since the structure will be paid for.  Growers should calculate their return based on their own yields and prices.  For us, we lost 40% of our blueberry crop in the first year that SWD arrived.  With the netting, we no longer lose any berries to SWD, nor to hail, high winds, or heavy rain.  A 40% loss of our blueberry crop now would be over $13,000 a year.  For us, that means that the entire cost of the structure and new netting is paid for in one year.  It would cost us more than $12,000 just to purchase a sprayer to use in our blueberries, not to mention the costs of materials, time to make applications, reduced customers, and reduced efficacy.  No sprayer will achieve less than 1% infestation of SWD over eight years, the way we have with netting.

Cornell has conducted an economic analysis looking at the economics of building and using exclusion netting.  While the study is not yet complete, the data so far indicates a three year payback for erecting a structure and covering it with exclusion netting.


Research conclusions:

We proposed to design, build and test a support structure for insect exclusion netting on a commercial blueberry planting because none were commercially available.  Prior to starting the project, Gintec Shade Technologies, based in Canada, started to modify their ginseng shade structures to use them for insect netting structures.  We tested two systems - a wood post and cable system, and a metal post and cable system.  The metal post system is far faster and easier to install and offers the advantage of easier post replacement if necessary and a lifespan that will last the life of the planting, or longer.  The improved height of the system, compared to our previous hoop system, makes it a more comfortable work area for both employees and Pick Your Own customers.  Pick Your Own customers absolutely love the atmosphere under the netting.  Since the netting diffuses the wind, it can feel quite hot under the netting so we only offer Pick Your Own in the mornings and evenings.  The system held up very well through four tropical storms and an accumulating hailstorm.  We feel the system is over-built, particularly since the netting only needs to be deployed for 2 - 2.5 months.  Gintec has listened to our concerns about cost and has changed their system to provide wider spans, reducing the cost of the structure.  Gintec believes that post spacing can be 15 feet apart on the perimeter and 30 feet in the interior for many sites.  Particularly windy sites should be set up with perimeter posts 12 feet apart and 24 ' apart in the interior. 

We experimented with the first netting panels joined by zippers and found them to be a great time-saver when deploying and storing the netting.  Widening the spans also reduces the price of the netting assembly for zippers.  The exclusion netting prevented SWD infestation in three years of the trial - zero percent infestation.  That level of control can never be achieved by spraying.  Growers who have high yielding plantings and high losses to SWD can recoup the costs of the system in one year.  Small scale growers in NYS, NH, MN, and VT have installed these systems and are very happy with the SWD-free berries they are able to produce.   Growers in Rhode Island, Pennsylvania, and Ohio are also building the structures.  NRCS cost sharing would be very helpful in speeding adoption of the technology and discussions have been started with NRCS and are on-going.  Our former US representative's office was very supportive of the technology.  Unfortunately, we now have a non-responding congresswoman.  For NRCS to move forward, I believe that grower groups need to band together and demand action to make this highly successful technology be more accessible to more growers.   

Participation Summary
2 Farmers participating in research

Education & Outreach Activities and Participation Summary

90 Consultations
5 Curricula, factsheets or educational tools
1 Journal articles
3 On-farm demonstrations
2 Online trainings
3 Published press articles, newsletters
2 Tours
11 Webinars / talks / presentations
2 Workshop field days

Participation Summary:

382 Farmers participated
126 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

I continue to get individual calls from growers that are interested in using exclusion netting for SWD management and I do individual consultations with them.  

Greg Loeb did a webinar for MSU Extension as part of their SWD webinar series during the summer. Excluding SWD from NY blueberries and raspberries.  July 31, 2020. There were 14 growers and extension educators attending.  

We held an on-farm field day on October 14th 2020 at The Berry Patch.  This was attended by growers and Extension personnel in person as well as live streamed to growers and service providers throughout New England via Zoom.  There were 14 growers and 6 service providers attending.  We demonstrated the components, supplies and tools used to construct the structure and led a tour through the planting, allowing growers to see each component up close and how the entire structure was put together.  There have also been 39 views on the UVM Extension Ag Engineering YouTube Channel.

Chris and Vern Grubinger held a SWD Management webinar on July 29, 2020 which featured this project as well as other support structures put up by growers, many of whom I have consulted with prior to building their structures.  Approximately 20 growers attended the webinar, the video recording of it on the Vermont Veg and Berry Growers page has had 30 views and it has had 229 views on the UVM Extension Agricultural Engineering YouTube channel. 

Chris spoke to the Northeast Tree Fruit Extension Workers IPM meeting on October 19, 2020.  "Designing exclusion netting support systems that provide long term control of SWD and maximum utility for berry farmers".  46 attendees.

Laura McDermott gave at least 6 presentations about the netting system at Master Gardener trainings in New York State.  Estimated numbers of gardeners reached - 60.

Chris gave a virtual presentation at the NY Produce Expo on January 15, 2021 and I was in attendance to assist with any questions.  62 growers tuned into the virtual presentation and it has received 135 views on the UVM Extension Ag Engineering YouTube channel.

Dale-Ila had Spectrum News come to The Berry Patch in late July and do a TV news article about the project.  It can be viewed here:

Laura discussed exclusion netting with several different growers in her Extension work and through her "Berry Office Hours", held remotely during the summer of 2020.  Berry Office Hours continued in 2021 and she discussed netting with growers during these hours in 2021 and did consultations as well.  She has had approximately 32 consultations during 2020 and 2021.

Chris and I have consulted with Anna Wallingford and Jeremy Delisle from UNH Extension about rolling out a program in NH that will offer some cost sharing to growers through a NRCS Conservation Innovation Grant to assist growers with modifying existing support structures or building support structures to use exclusion netting.  Jeremy visited The Berry Patch in June 2021 to view the structure in person and I provided more consultation through the summer, fall and winter of 2021/2022.

I had several conversations with state level NRCS staff in NYS educating them about the need and utility of exclusion netting systems.  Based on conversations that I first initiated 5 years ago, they have added exclusion netting to their list of approved practices for pest management.  Unfortunately, the rate included is not high enough, but I am working on getting them documentation to get those rates raised.

In 2021, using funds that I obtained from New York State, a second demonstration site with a metal post structure and exclusion netting was built in Western NY to provide a location for growers in Western New York, Northwest Pennsylvania, and Eastern Ohio to visit.  A field day was held there on September 15, 2021.  I participated remotely.  Paul Lucas, Owner of Gintec participated in person.  There were 13 adult attendees, 6 youth attendees, and 5 service providers.

On October 5, 2021, we held a field day at The Berry Patch for growers to see the exclusion netting system and see how we start the process for winter storage of the netting.  22 growers and 8 service providers attended.  We discussed lessons learned over two years of using the system and growers were able to see the entire system while it was deployed.  There was great interest in the system at the meeting.  As part of the meeting, we had a NYS NRCS state leader join us remotely to talk about how growers can apply for cost share dollars for the netting.  Paul Lucas from Gintec and Ted Storozum from Tek-Knit Industries also attended remotely.  At least two growers who attended built a support structure and used exclusion netting in 2022.

On October 11th, 2021 we hosted a tour for our Congressman, Antonio Delgado, and his staff, to see the system, learn how well it has worked for our commercial blueberry planting, and request his help in approaching USDA to offer cost-share assistance to farmers who are interested in putting up these systems.  At least 11 service providers from many different agencies, including Soil and Water Conservation, NY Dept of Ag and Markets, NYS IPM, Cornell University, Agricultural Stewardship Association, Cornell Cooperative Extension, UVM Extension, and the NYS Berry Growers Association attended. 

Yates County Cornell Cooperative Extension.  November 2021.  Presentation on Using Exclusion Netting for SWD Management.  10 service providers.

Harvest NY Team meeting November 2021.  Presentation on Using Exclusion Netting for SWD management.  10 service providers.

NYSBGA Board of Directors Meeting.  December 2021.  Update on Exclusion Netting work.  10 growers, 5 service providers.

Chris produced 5 videos that are posted on the UVM Ag Engineering YouTube channel that teach growers how to lay out and start building a support structure.  Fall 2021 and Spring 2023.  So far, there have been over 788 cumulative views on the UVM Extension Ag Engineering You Tube channel.
Overview - Post and Wire Support Structure for Spotted Wing Drosophila (SWD) Exclusion Netting
Basic Layout - Truing and Squaring a Large Rectangular Layout - SWD Exclusion Netting
Posts - Layout, Auguring Holes and Driving Anchors for SWD Exclusion Netting
Setting Perimeter Posts and Tightening Perimeter Cables for SWD Exclusion Netting
Installing Netting Panels, Vestibules, and Winter Storage - SWD Exclusion Netting

On February 8, 2022, Laura gave a presentation about using Exclusion netting during a SWD update webinar.  There were 136 participants - approximately 16 of them were service providers.

I spoke about using exclusion netting at the MOSES Conference in Wisconsin on February 24th, 2022.  There were 50 in-person attendees.


Learning Outcomes

32 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:

I personally learned a great deal about the construction process for building a structure that is specifically designed for exclusion netting.  At least twelve structures have been or are currently being constructed.

Another grower that attended the field day said that she got at least three great ideas on how to make her own support structure better and to be more efficient in how she deploys the netting in the spring and takes down the netting in the fall.

I continue to get calls from growers interested in using exclusion netting and I am now able to pass on advice regarding what type of materials to use and the advantages and disadvantages of using metal vs wood supports.

Growers in NYS, NH, VT, RI, PA, OH, and MN have erected or have committed to building support structures for exclusion netting.  

NH Cooperative Extension received a Conservation Innovation Grant in September of 2020 to provide some cost share funding to assist growers in erecting or modifying existing structures to use exclusion netting.  More growers are investigating the possibilities of building systems of their own design.  

Project Outcomes

14 Farmers changed or adopted a practice
2 Grants applied for that built upon this project
2 Grants received that built upon this project
$151,995.00 Dollar amount of grants received that built upon this project
2 New working collaborations
Project outcomes:

This project has been very rewarding to work on in many ways.  It's been really great to see the cooperation and true teamwork that this project has brought about.  The team is comprised of those of us at The Berry Patch, UVM Extension, Cornell Cooperative Extension, and Cornell Agri-Tech.  Growers, Extension staff, and researchers have worked together as a true team to bring this project to fruition to help the industry fight this devastating pest. This improved support structure made it much easier to be able to offer pick your own blueberries in the year that we really needed to expand our marketing channels, due to Covid restrictions and the subsequent loss of other markets.  The customers that came to our farm to do Pick Your Own blueberries were absolutely thrilled with the whole exclusion netting system - from the aspect of us not needing to spray for this invasive insect to the very calming, pleasant environment that exists under the netting.  Almost all Pick Your Own growers that I have talked with have expressed extreme pessimism about an exclusion system working for Pick Your Own operations.  My experience was the exact opposite.  I did not receive one negative comment from Pick Your Own customers and every single one talked about it being the best pick your own experience they had ever had.

Two other grants came about because of this project.  In December 2020, NYS Dept of AG and Markets awarded a grant totaling $72,109 to construct and demonstrate an exclusion netting support structure system on an organic blueberry planting in Western New York.  The title of the project is "Demonstration and Education on the construction and efficacy of a post and wire support system for insect exclusion netting of field grown berries in NY".  This was a direct result of the work that has been done at The Berry Patch as growers in Western New York wanted to be able to see a system without having to drive six hours to see the one at The Berry Patch.

NH Cooperative Extension received a Conservation Innovation Grant in September of 2020 to provide some cost share funding to assist growers in modifying existing structures to use exclusion netting.    The title of the grant is "New Hampshire IPM Cost Share Demonstration Program".  The grant award was for $$79,886.


Assessment of Project Approach and Areas of Further Study:

The project is complete but continues to provide multiple learning opportunities for many people.  Chris created 5 YouTube videos to teach growers how to build a structure on their own.  The videos are a great teaching tool and are receiving more and more views.  I think one of the keys to the success so far has been the teamwork aspect of all parts of the ag community working together to make this project happen for the benefit of the industry.  The great response to the project by the non-farm public has also been wonderful to see.

Gintec has changed their recommendations for post spacing to reduce the cost of the structure for both materials and time to construct it.  An economic analysis from Cornell is showing that the original structure can be paid for in three years.  Reduced materials and reduced labor will make that analysis even more favorable.

What I do know is that after using exclusion netting for SWD control for nine years, it is the most effective answer for SWD and I believe that this system holds promise for other insect problems in other crops.  Growing under netting, I have obtained unbelievable yields, yields equivalent to or exceeding yields in Oregon and Washington, the highest yields in the country.  The quality of the berries, and the premium price I can get for them because they are no-spray berries has given me the numbers to show that the entire system can be paid off in less than one year.  

We started our farm from a worn out old corn field with no improvements.   Twenty years later I own 215 acres, have 5 greenhouses, a full complement of farm equipment, and zero debt.  I can retire without selling my farm for retirement income.  I was able to pay off my farm mortgage 5 years early, largely because of the income that I get off half an acre of no-spray blueberries that are protected from a devastating insect by using exclusion netting. Consumers love the system and the fact that they can get no-spray berries.  It's another example of how protected agriculture is the way of the future, particularly for small scale growers.  It can provide a decent living for growers anywhere in the country who are innovative, pay attention to detail, and keep consumer trends in the forefront of their marketing, as long as they are willing to make the investment.  When that investment can be repaid in three years or less, (less than one year in our case), there is no reason not to make the investment.  

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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.