Biological Control of Corn Rootworm in Conventional and Organic Corn Production

Final report for LNE19-383

Project Type: Research and Education
Funds awarded in 2019: $199,199.00
Projected End Date: 04/30/2022
Grant Recipient: Cornell University
Region: Northeast
State: New York
Project Leader:
Elson Shields
Cornell University
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Project Information

Summary:

Corn rootworm (CRW) is the primary limiting insect pest of corn production in North America with the U.S. corn growers spending more than $2 billion to manage this insect below economic levels using management tools which include soil insecticide, annual crop rotation, or Bt-rootworm toxins incorporated into the plants. Research at Cornell for the past 30 years has shown field efficacy against CRW as well as multi-year persistence from a single inoculation. The data has shown persistent biocontrol nematodes can provide sufficient control of CRW alone on non-GE corn varieties or work with and are compatible with other management strategies like Bt, RNAi, or soil insecticides to reduce CRW resistance development. Application techniques have been developed and field tested to inoculate corn fields with biocontrol nematodes in NY corn fields using modified pesticide sprayers or spread using liquid dairy manure as a carrier.

The focus of this project was to establish multiple demonstration sites within NY, PA, and VT to further test the potential of this biological control technology against CRW and identify potential problems with technology adoption. In total, 22 farms across three states participated in this project to test the concept of using biocontrol nematodes to suppress corn rootworm in continuous corn fields without the aid of other CRW suppression technology. Growers were assisted with applications of biocontrol nematodes by researchers or certified applicators with previous experience using the developed application techniques. The application process proved to be famer/applicator friendly however, discussions with both led to improvements by the project conclusion that improved the delivery system, a direct result of the interaction between all parties.

Persistent biocontrol nematode technology demonstrated the effectiveness on CRW in all locations, proved to be compatible with other management tools like Bt-RW and operates as a second independent mortality factor to reduce the insect resistance development to other management strategies. While the research, adoption, and outcome from this project were positive, two items remain to finish the research: 1) efforts need to be intensified to explore the upper limits of CRW biocontrol with biocontrol nematodes and 2) at what CRW population levels and which environmental conditions will prevent biocontrol nematodes from providing acceptable CRW control? Data from multiple sites suggest reduced CRW control under drought conditions. In addition, the low-tech mass rearing system which has provided biocontrol nematodes for >34,000 NY acres needs to be revisited to improve biocontrol nematode shelf life and to improve the nematode delivery system to the farmer/applicator; research in the final year focused on reducing the applicator labor to prepare the nematode product for application.

The ability of biocontrol nematodes to persist in continuous corn for multiple growing seasons from a single application has shown reduction of CRW damage in multiple locations and has increased adoption of the practice by growers in multiple states. The data suggests that growers’ best management practice is to deploy persistent biocontrol nematodes in coordination with other management strategies. The data collected throughout this project shows complete compatibility with the Bt-RW technology currently available in corn varieties and has shown biocontrol nematode persistence across crop rotation for those farms not growing continuous corn. Growers willing to adopt this technology are adding a management strategy that provides a mortality factor completely independent of other management tactics that will help in two ways. First, the reduction of corn rootworm pressure directly and secondly, the biocontrol nematodes attack the survivors of the other management tactics (e.g. toxins), potentially reducing the speed of resistance development, making the overall management strategy more durable.

Performance Target:

Fifty farms in NY, VT, and PA will implement biological control on 500 acres of corn to manage corn rootworm and as a result will reduce production costs by $50 per acre by reducing corn rootworm management costs (using non-Bt-CRW corn seed or eliminate soil insecticide).

Introduction:

Western corn rootworm (CRW), Diabrotica virgifera virgifera LeConte, is one of the most damaging insect pests to U.S. agriculture with damage and control costs exceeding $1 billion annually.  Historically, this insect species has been managed using soil insecticides, crop rotation and most recently, corn varieties that are genetically modified to contain a toxin to kill feeding corn rootworm larvae (CRW-GM).  Currently, all of these technologies are failing in areas across the US corn production.  While CRW populations are not economically damaging every year in the Northeast, the damage is economically significant in the years of moderate to high populations.

With rapidly increasing CRW-GM seed costs, reduction in CRW-GM efficacy, continued eastward movement of the rotation-resistant variant, low milk prices and increasing pressure on the milk producers by milk processors to produce GM free milk for public consumption, producers are looking for alternatives for rootworm control.

Beginning in 2014, a research project began focusing on the inoculation of first-year corn fields with native NY entomopathogenic nematodes (EPNs) to address the rootworm issue. These fields would remain in continuous corn for multiple years (continuously planted to corn through 2019). In 2016, two years after inoculation, an economic population of CRW larvae were present in the field plots with the untreated check plots suffering almost two nodes of roots destroyed, an economically damaging level.  In the EPN treated plots (inoculated just once in 2014), EPNs protected corn roots from CRW larval feeding and plants only suffered 0.25 of a root node damage.  This level of protection rivaled that provided by CRW-GM events planted in the same trial.  Within this research project, economically damaging CRW populations did not materialize in 2017, 2018 or 2019 seasons.  However, the EPN populations in the soil have remained high enough to respond to the next economically damaging outbreak of CRW larvae.

Our approach for this project was to disseminate what we have learned and provide an opportunity to reduce damage as a result of rootworm while decreasing input costs and maintaining yield, allowing an overall cost benefit to our producers. The cost benefit associated with the application of bio-control nematodes is dependent on the number of years of continuous corn and the rate of bio-control nematodes used to establish the population of nematodes in the soil. On organic farms, biological control of soil insects (corn rootworm. wire worm) will decrease damage and increase yield.

If the bio-control nematodes are applied into a first year corn field at either the full ($90/ acre) or reduced rate ($30/acre), the field can be planted to non-Bt-CRW corn varieties because the CRW larval feeding pressure is non-existent.  In subsequent years with the pest suppression of the bio-control nematodes, the field can be planted to non-Bt-CRW corn varieties.  Under this scenario, cost recovery from the bio-control nematode application is immediate.  Since the price differential between non-Bt-CRW corn varieties and Bt-CRW corn varieties is approximately $50/acre, the cost of the nematode application is recovered in 1-2 years depending on the nematode application costs.

Cooperators

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  • Dr. Heather Darby (Researcher)
  • Dr. Victor Izzo (Educator and Researcher)
  • Scott Lewins (Educator and Researcher)
  • Dr. John Tooker (Educator and Researcher)
  • Antonio Testa (Researcher)

Research

Hypothesis:

1) A single inoculation of the biocontrol nematode strains/species shown successful in NY will be inoculated and established in VT and PA research/agricultural fields. Similar to NY, these populations will persist for multiple growing seasons and provide effective ongoing control of corn rootworm larval feeding.

2) Without the assistance of CRW-GM varieties, NY, PA and VT farmers will test biocontrol nematodes under their growing conditions for control of corn rootworm in their continuous corn fields.

3) Application of persistent biocontrol nematodes will reduce damage from soil insects and may increase yields in organic production systems.

Materials and methods:

Vermont

Borderview Farm.

2019

A demonstration plot (0.40ac) was established in a 14 acre field (N 45.00479, W -73.30797) owned and operated by Roger Rainville, Alburgh, VT. Plot design included eight, 0.05 acre blocks. The area designated for the demonstration site was assayed prior to nematode establishment on May 30, 2019 to determine if an existing nematode population was present. A total of 200 soil cores (25/plot)  were collected following established protocols designed by the Shield’s Lab. Conducting soil samples involves removing each sample from the soil and splitting into upper 2" and 3-6" portions that would be used to bioassay for nematode presence. Soil cores were returned to the laboratory and bio-assayed using a standard technique with wax moth larvae as an indicator for the presence of biocontrol nematodes in the sample.

Using the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)), were reared for this demonstration site, and then applied to a continuous corn crop once plants emerged on May 30, 2019. A single cup of each Steinernema species were washed into a 35g can, then using a 2g watering can EPN infective juveniles (IJ) were applied at a rate of 5-10 million EPNs per species per treated block. Four blocks were treated with nematodes and the other four blocks remained untreated. Each treated block received a two-species combination, the total number of IJs per treated block were 10-15 million. A total of 50-60 million nematodes were reared for the Borderview Farm site.

Soil cores were collected 40d and 120d post application to verify establishment of EPNs and to determine persistence populations within the treated blocks.

To determine if the combination of traited corn and EPNs impact the number of emerging adults, the emerging adults must be collected and compared across variety and nematode treatment; CRW adults captured using screen tents. A single, Coleman 10' x 10' screen tent, were placed within each demo-block prior to the anticipated adult CRW emergence around mid-July. All screen tents (total of 16) were set up by July 6th, 2019. Observations for CRW adult emergence began on July 8, 2019. Tents were checked for adults 1-2X week for nine weeks.  Adults collected from the tents were returned to the laboratory, the number and sex of any adults collected during an observation were recorded.

Evaluation for feeding damage by CRW larvae within the untreated and treated plots at the Borderview Farm was conducted on August 27th. Researchers visited the site where corn roots were labeled, (Untreated & Treated Blocks),  10 randomly selected corn roots were dug out of each replicated block, washed and evaluated for feeding damage using the Iowa scale. Root ratings were conducted in a double blind format; the rating information was recorded.

2020

Soil cores were collected 290d and 484d post application to verify persistence populations within the treated blocks of applied EPN species.

Similar to 2019, to determine if the presence of bio-control nematodes impact the number of emerging adults, the emerging adults were collected once again using Coleman 10' x 10' screen tents from both the bio-control nematode treated and untreated plots. Two, 10' x 10' screen tents were placed within each demo plot prior to the anticipated adult CRW emergence around mid-July (Northeast and Southwest corners). All screen tents (total of 16) were set up by July 10th, 2020. Observations for CRW adult emergence began on July 13th, 2020. Tents were checked for adults 1-2X week for seven weeks. Adults collected from the tents were returned to the laboratory, stored in alcohol, and then separated by species (Western corn rootworm vs. Northern corn rootworm) in the fall. The number of any adults collected during an observation date were recorded for each research plot.

The evaluations for root damage caused by corn rootworm within the untreated and treated plots at Borderview Farm were conducted on August 13th, 2020. Within each replicated plot, ten randomly selected corn roots were dug out, washed and evaluated for feeding damage using the Iowa 0-3 root damage scale. Root ratings were conducted in a double blind format and the rating information was recorded.

2021

The goal was to do a spring 2021 soil assay to evaluate the long-term persistence of biocontrol nematodes at this location. However, the research plots were accidently worked up with a disc. In the prior two field seasons, planting protocols were to no-till corn in the spring starting with the control plots and ending in the nematode treated plots to avoid contamination. Researchers discussed and decided to plant the corn as planned and then sample the untreated plots for any presence of biocontrol nematodes to document any contamination. Results found by the assay would determine the course of action in these plots for a fall bioassay, root evaluation, and adult collection of emerging corn rootworm. Soil cores were collected 740d within the untreated plots and all research plots were assayed 880d post application to verify persistence populations within the treated blocks of applied EPN species. Samples were evaluated at Cornell University using the protocols developed by the Shields’ Lab.

Similar to 2019 and 2020, to determine if the presence of bio-control nematodes impact the number of emerging adults, the emerging adults were collected once again using Coleman 10' x 10' screen tents from both the bio-control nematode treated and untreated plots. Two, 10' x 10' screen tents were placed within each demo plot prior to the anticipated adult CRW emergence around mid-July (Northeast and Southwest corners). All screen tents (total of 16) were set up by July 12th, 2021. Observations for CRW adult emergence began on July 15th, 2021. Tents were checked for adults 1-2X week for seven weeks. Adults collected from the tents were returned to the laboratory, stored in alcohol, and then separated by species (Western corn rootworm vs. Northern corn rootworm) in the fall. The number of any adults collected during an observation date were recorded for each research plot.

The evaluations for root damage caused by corn rootworm within the untreated and treated plots at Borderview Farm were conducted on August 20th, 2021. Within each replicated plot, ten randomly selected corn roots were dug out, washed, and evaluated for feeding damage using the Iowa 0-3 root damage scale. Root ratings were conducted in a double-blind format and the rating information was recorded.

Bridgeman View Farm.

2019

A demonstration plot was established in a 10 acre field (N 44.9777, W -72.9205) owned and operated by Tim Magnant, Franklin, VT. Plot design involved treating 5 acres of the field with EPNs and leaving the other 5 acres untreated. Using the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)), were reared for this demonstration site, and then applied to a continuous corn crop once plants emerged on May 31, 2019.

Two cups of each Steinernema species were washed into a 35g can then added to a 50g tank attached to an ATV, EPN infective juveniles (IJ) were applied at 50gal of water per acre using an ATV-pulled 50gal trailer sprayer. The 5 acre block received a two-species combination, the total number of IJs applied within the 5 acre block was 42 million per species; a total of 84 million nematodes were reared for this demonstration plot.

Soil cores were collected 50d and 150d post application to verify establishment of EPNs and to determine persistence populations within the treated acreage.

2020

Soil cores were collected from the demonstration site on May 8th, 2020 and October 14th, 2020 (330d and 523d post application respectively) to verify persistence populations of the EPN species within the treated 5ac. Samples were evaluated at the University of Vermont by the UVM Extension NWCS Team using the protocols developed by the Shields’ Lab at Cornell University.

2021

Soil cores were collected from the demonstration site on October 27th, 2021, 880d post application to verify persistence populations of the EPN species within the treated 5ac. Samples were evaluated at Cornell University using the protocols developed by the Shields’ Lab.

Island Dairy

 2021

A demonstration plot was established in a 10-acre field (N 44.870919, W -73.259778) owned and operated by Andre Quintin, North Hero, VT. Plot design involved treating 5 acres of the field with EPNs and leaving the other 5 acres untreated. Using the multi-species approach, two native NY strains of biocontrol entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)), were reared for this demonstration site, and then applied to a continuous corn crop once plants emerged on May 28, 2021. 

Two cups of each Steinernema species were washed into a 35g can then added to a 50g tank attached to a Massey Ferguson 35, EPN infective juveniles (IJ) were applied at 50gal of water per acre using a 50gal 3-pt hitch tractor mounted sprayer. The 5-acre block received a two-species combination, the total number of IJs applied within the 5-acre block was 42 million per species; a total of 84 million nematodes were reared for this demonstration plot. 

Soil cores were collected from the demonstration site on October 27h, 2021-150d post application to verify persistence populations of the EPN species within the treated 5ac. Samples were evaluated at Cornell University using the protocols developed by the Shields’ Lab.

Pennsylvania

Larson Ag Research Farm. Larson Ag Research Farm.

2019

A demonstration/research plot (3.0ac) was established in a 6 acre field (N 40.7117, W -77.9443) operated by Penn State University in Pennsylvania Furnace, PA. Plot design is a 2X2 factorial design; sixteen, 0.18 acre blocks (100’ x 40’ per block). The area designated for the demonstration/research site was assayed prior to nematode establishment on May 29, 2019 to determine if an existing nematode population was present. A total of 80 soil cores (5/plot) were collected following established protocols designed by the Shields’ Lab. Using the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)), were reared for this demonstration/research site, and were applied on May 29, 2019, prior to no-till corn planting. Eight blocks were treated with nematodes and the other eight blocks remained untreated. The field has been in continuous corn for two years prior to this research.

Application was done using a truck with two-fifty gallon tanks filled with EPNs and water. The eight bio-control nematode plots received a two-species combination; four cups of each EPN species per acre; the equivalent rate of 84 million IJs per acre or 15 million per 0.18 ac plot and applied in 50 gpa water using a sprayer mounted on a 4x4 pickup. A total of 340 million nematodes were reared for this demonstration plot.

Soil cores were collected 30d post application to verify a successful inoculation. A total of 200 samples were collected following established protocols designed by the Shield’s Lab from this demonstration site. Within each treated block, 25 random samples were collected. We were unable to conduct a fall assay to determine persistence levels in the fall. A pre-planting assay will be conducted at this site in Year 2 (early May).

To determine if the combination of traited corn and EPNs impact the number of emerging adults, the emerging adults must be collected and compared across variety and nematode treatment; CRW adults captured using screen tents. A single, Coleman 10' x 10' screen tent, were placed within each demo-block treated with EPNs and within four, non-EPN blocks prior to the anticipated adult CRW emergence around mid-July.  All screen tents (total of 12) were set up by July 10th. Observations for CRW adult emergence began on July 15, 2019. Tents were checked for adults 1-2X week for eight weeks.  Adults collected from the tents were returned to the laboratory, the number and sex of any adults collected during an observation were recorded.

Evaluation for feeding damage by CRW larvae within the untreated and treated plots at the Larson Ag Research Farm site was conducted on August 8th, 2019. Researchers visited the site where corn roots were labeled, (Untreated & Treated Blocks),  10 randomly selected corn roots were dug out of each replicated block, washed and evaluated for feeding damage using the Iowa scale. Root ratings were conducted in a double blind format; the rating information was recorded.

2020

Soil cores were collected prior to the field site being planted with corn on May 13th, 2020, 350d post application to verify persistence populations within the treated blocks of applied EPN species. Post-harvest soil sampling at the site was conducted on November 5th, 2020, 526d post application. For the spring evaluation, at each sample point, two samples were removed; samples were labeled and kept separate. One set of samples remained at Penn State University and were evaluated using the protocols developed by the Shields’ Lab at Cornell University. The second set of samples were delivered to the Shields’ Lab for a comparison reading of the assay conducted at the Penn St. location.

Similar to 2019, to determine if the presence of bio-control nematodes impact the number of emerging adults, the emerging adults were collected once again using Coleman 10' x 10' screen tents from both the bio-control nematode treated and untreated plots. A single Coleman 10' x 10' screen tent were placed within each demo-blocks treated with EPNs and within four non-EPN blocks prior to adult CRW emergence around mid-July. All screen tents (total of 12) were set up by July 17th, 2020. Observations for CRW adult emergence began on July 21st, 2020. Tents were checked for adults 1-2X week for nine weeks.  Adults collected from the tents were returned to the laboratory and stored in alcohol until the fall. The number of any adults collected during an observation date were recorded for each research plot.

The evaluations for root damage caused by corn rootworm within the untreated and treated plots at Larson Ag Research Farm were conducted on September 3rd, 2020. Within each replicated plot, ten randomly selected corn roots were dug out, washed and evaluated for feeding damage using the Iowa 0-3 root damage scale. Root ratings were conducted in a double blind format and the rating information was recorded.

2021

Due to miscommunications between the Shields’ Lab and Tooker Lab, a spring soil assay was not conducted in 2021. This research site had the corn planted by the end of May 2021 following the same protocols as the past 2-years. A post-harvest sampling at the site was conducted November 23, 2021, 910d post application to verify persistence populations within the treated blocks of applied EPN species. Samples from this assay were delivered to Cornell University and evaluated by the Shields’ Lab.

Similar to 2019 and 2020, to determine if the presence of bio-control nematodes impact the number of emerging adults, the emerging adults were collected using Coleman 10' x 10' screen tents from both the bio-control nematode treated and untreated plots. A single Coleman 10' x 10' screen tent were placed within each demo-blocks treated with EPNs and within four non-EPN blocks prior to adult CRW emergence around mid-July. All screen tents (total of 12) were set up by July 21st, 2021. Observations for CRW adult emergence began on July 23rd, 2021. Tents were checked for adults 1-2X week for nine weeks.  Adults collected from the tents were returned to the laboratory and stored in alcohol until the fall. The number of any adults collected during an observation date were recorded for each research plot.

The evaluations for root damage caused by corn rootworm within the untreated and treated plots at Larson Ag Research Farm were conducted on August 25th, 2021. Within each replicated plot, ten randomly selected corn roots were dug out, washed, and evaluated for feeding damage using the Iowa 0-3 root damage scale. Root ratings were conducted in a double-blind format and the rating information was recorded.

Schrack Farm Resources.

2019

A demonstration plot was established in a 60 acre field (N 41.0246, W -77.3256) owned and operated by Harbach and Schrack families in Loganton, PA. Plot design involved treating 2 acres of the field with EPNs and leaving the other 58 acres untreated. Using the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)), were reared for this demonstration site, and then applied to a continuous corn crop once plants emerged on June 14, 2019.

Bio-control nematodes were applied into the treated area at a rate of 84 million IJs per acre using a modified, self-propelled pesticide sprayer (we removed all filters from the sprayer to allow the nematodes to flow through the lines) to deliver the nematodes onto the ground with 50gpa water. Application was made early in the morning on a cloudy, misty day to prevent bio-control nematodes from UV exposure. A total of 168 million IJs were reared for this trial.

Soil cores were collected 100d post application to verify a successful inoculation. A total of 25 samples were randomly collected from this demonstration site treated acreage following established assay protocols. An additional 25 samples were collected in an area outside of the treated acreage.

2020

On 2 Oct 202, the Tooker Lab collected soil cores at Schrack Farms. They collected 25 samples from the nematode-treated portion of this demonstration site and an additional 25 samples from an equivalent area outside of the treated acreage. On 7 October, purchased waxworms were introduced into the soil samples to determine how active the nematodes were.  After 7 days of exposure, we assessed waxworm mortality.

Penn State restrictions due to COVID-19 prevented enrollment of additional farmers in our project in 2020.

2021

During 2020, the owners of the farm had planted the research plot area that had been treated with biocontrol nematodes to sorghum sudangrass after a severe draught in 2019 and wanted a more reliable forage harvest than corn silage. The field had been in continuous corn for nearly a decade before that. The Tooker Lab had not been notified and despite the change of crop, went ahead and assayed the area, evaluated the samples, and then reported the result last year.

The research plots at Schrack Farms were not assayed in 2021 since corn rootworm would not be expected to survive on the sudangrass. COVID-19 restrictions prohibited recruitment of new growers for 2021.

New York

Established Demonstration Plots.

2019

Three NY sites were previously established at both a research farm (2014) and two commercial production fields (2017). For each of the demon sites, EPNs were reared using the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)):

  • Musgrave Research Farm, Popular Ridge NY (72353, -76.66213), has been in continuous corn since 2014. The plot design includes two nematode treated areas (~0.6 acres) including non-BT-CRW traited corn and commercially available GMO-BT-CRW corn varieties; blocks were treated with bio-control nematodes on June 20, 2014.
  • Stokoe Farms, Scottsville, NY (N 42.96965, W -77.72081). The Stokoe Farm site, owned and operated by Selden Stokoe and his sons was established in a 100+ acre field and has been in continuous corn since 2017. The plot design includes eight, 0.5 acre blocks. Four blocks were treated with EPNs on June 9, 2017 while the other four blocks will remain untreated.
  • Morning Star Farm, Adams, NY (43.8612, -76.1252) owned and operated by Dave & Lisa Magos was established in a 132+ acre field and has been in continuous corn since 2017, the farm follows no-till practices. The plot design includes eight, 0.5 acre blocks. Initial plot design had each plot being split and planted with either conventional corn or a CRW-BT variety. Four blocks were treated with EPNs on May 17, 2017 while the other four blocks will remain untreated.

Year 1 Demonstration Sites. For 2019, the goal of the Shield’s Lab was to recruit 20 new farms whom would treat a single field with untreated check strips using one of two application methods; common pesticide sprayers or liquid manure. Typically, recruitment is done during the winter meeting cycle, however notification of approval of this project was announced after the meeting cycle had been completed, and as a result the Year 1 goal of 20 farms was not met.

Pesticide Sprayers. The current recommended application method of biocontrol nematodes is to rinse nematodes with high volumes of water through fine mesh screens into a holding tank. The nematode solution is then dumped into a field sprayer equipped with streamer nozzles or drop tubes.  The nematodes are then field applied using high volumes of water, 50 gallons or more per acre. The following farms adhered to the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)) in establishing their demonstration plots:

  • Village View Farm, Castorland, NY, owned and operated by Merv Moser. Field trial was established in a 65 acre field and will be in continuous corn for a minimum of 3-years
  • McCauley Farms, Mt. Morris, NY, owned and operated by Brian McCauley. Field trial was established in a 10 acre field and will be in continuous corn for a minimum of 3-years

Liquid Manure Applications. Beginning in 2016, the Shield’s Lab has worked closely with Mike Hunter, Cornell University Cooperative Extension, North Country Regional Ag Team, to develop a more farmer friendly method to apply biocontrol nematodes to their fields. The result, using liquid manure as the “carrier” of EPNs. Applying EPNs, following the multi-species approach using liquid manure as the delivery method; eliminates the need for additional field operation, is effective in protecting EPNs from UV light, and allows farmers to apply throughout the day, versus on in the dusk hours or when weather conditions are overcast to rainy. Research continues on the most effective rate to use. The following farms established 1-3 acre demonstration plots within existing continuous corn fields:

  • Reed Haven Farm, Adams Center, NY owned and operated by Dan Reed
  • Murcrest Farm, Copenhagen, NY owned and operated by Lynn Murray
  • Garden of Eden Farm, Philadelphia, NY owned and operated by Mike Kiechle
  • Horst Farm, Belleville, NY owned and operated by the Horst Family
  • Milkstreet Dairy Farm, Tylerville, NY owned and operated by the Ferry Family
  • Birchcreek Farm, Ellisburg, NY owned and operated by the Bast Family
  • CTS Dairy, Ellisburg, NY owned and operated by Steve Eastman
  • Porterdale Farms, Adams Center, NY owned and operated by the Porter Family
  • North Harbor Dairy, Sackets Harbor, NY owned and operated by Ron Robbins
  • Demko Farms, Martinsburg, NY, owned and operated by Jerome Demko
  • Marks Farms, Lowville, NY, owned and operated by the Robbins Family

Tracking EPNs. Two of the three existing demonstration sites (Musgrave and Stokoe) were assayed during Year 1 to track persistence and population levels in the existing demonstration plots. At Musgrave Research Farm, assays were conducted 1,816d and 1,877d post application. For each assay, 320 samples were collected, soil cores were then returned to the laboratory and bio-assayed using a standard technique with wax moth larvae as an indicator for the presence of biocontrol nematodes in the sample. The Stokoe Farm site was assayed 759d post application to verify multi-year persistence of EPNs. Soil cores were collected from the EPN treated and untreated plots; continuous corn combination blocks (25/plot). For the newly established demonstration sites, soil cores were collected 45-60d post application to verify establishment of EPNs. We were unable to do a fall assay at the end of the growing season, a spring assay to document over wintering populations will be conducted.

Documenting Root Damage. Evaluation for feeding damage by CRW larvae within the continuous corn plots was only done at the Musgrave Research Farm, Popular Ridge, NY. Root damage assessment began August 5th and concluded on August 8th. Researchers visited the site where corn roots were labeled, (Untreated & Treated Blocks), then dug out of each replicated block for each nematode treatment. Each variety within a replicated block had 10 corn roots removed (80 per block-40 in between rows and 40 from inside the tents), washed and evaluated for feeding damage using the Iowa scale. A similar assessment was conducted within the untreated replicates as well. The number of corn roots was pre-determined before arriving based on previous analysis parameters. Corn roots were removed (60 per block-30 in between rows and 30 from inside the tents) from each variety in the comparison plot (non-treated nematode) and evaluated for feeding damage using the Iowa scale.

Corn roots were then washed, evaluated, and rated for feeding damage using the Iowa scale (0-3 scale) at the Musgrave Research Farm on August 8, 2019. Root ratings were conducted in a double blind format; the rating information was recorded.

CRW Emergence Evaluation. To determine if the combination of traited corn and EPNs impact the number of emerging adults, the emerging adults must be collected and compared across variety and nematode treatment; CRW adults captured using screen tents. A single, Coleman 10' x 10' screen tent were erected in the corn plots located at Musgrave Research Farm, prior to the anticipated adult CRW emergence around mid-July. The process to set up these screen tents began on July 9th; a single Coleman 10' x 10' screen tent were placed over the Steinernema sp. variety x treatment x replication. All screen tents (total of 16) were set up by July 10th. Researchers determined that the evaluation on the Steinernema feltiae and Hetrorhabditis bacteriophora treated areas would not occur in 2019, due to significant cross contamination within that previously treated section from farm equipment. Going forward with an evaluation using current methods, assay work and root evaluation, would not be useful and relevant to the current project.

An additional study on non-nematode treated corn using the same varieties was conducted in parallel plot to the main research plot. Those corn rows also had single Coleman 10' x 10' screen tents added to collect any surviving adult CRWs. All screen tents (total of 12) were set up by July 12th.

Observations for CRW adult emergence began on July 15, 2019. Tents were checked for adults 1-2X week for ten weeks, concluding on September 17th.  Adults collected from the tents were returned to Cornell University and placed in cold storage until personnel were able to sort through each observation date.  The number and sex of any adults collected during an observation were recorded.

Established Demonstration Plots.

2020

For the 2020 reporting period, the demonstration site located at the Musgrave Research Farm, Popular Ridge, NY was the only site accessible to the Shields’ Lab to conduct research activities. The entire field was planted to corn on May 14th, 2020.

Year 2 Demonstration Sites - For 2020, the goal of the Shield’s Lab was to recruit 20 new farms whom would treat a single field with untreated check strips using one of two application methods; common pesticide sprayers or liquid manure. Typically, recruitment is done during the winter meeting cycle, however with the onset of COVID-19 this past year, the Shields’ Lab had to rely more on using extension agents and consultants as a means to reach potential new farms. In addition, mandates on limiting travel and in-person meetings by Cornell University made it more difficult to attain our goal of 20 new farms, which we were unable to do.

Pesticide Sprayers. The current recommended application method of biocontrol nematodes is to rinse nematodes with high volumes of water through fine mesh screens into a holding tank. The nematode solution is then dumped into a field sprayer equipped with streamer nozzles or drop tubes.  The nematodes are then field applied using high volumes of water, 50 gallons or more per acre. The following farms adhered to the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)) in establishing their demonstration plots in 2020:

  • Village View Farm, Castorland, NY, owned and operated by Merv Moser. Field trial was established in a 75 acre field and will be in continuous corn for a minimum of 3-years
  • Dziedzic Farm, Bliss, NY, owned and operated by Eric Dziedzic. Field trial was established in a 200 acre field which has been in continuous corn for the past several years
  • Swill Valley Farm, Warsaw, NY, owned and operated by Hubert Wick. Field trial was established in a 50 acre field which has been in continuous corn for the past several years
  • Table Rock Farm, Castile, NY, owned and operated by Willard Degoyler. Field trial was established in a 134 acre field which has been in continuous corn for the past several years

Liquid Manure Applications. There were no additional farms for 2020 that chose to apply bio-control nematodes using the liquid manure application method.

Tracking EPNs. Only the demonstration site at the Musgrave Research Farm was assayed during Year 2 to track persistence and population levels in the existing demonstration plots. At Musgrave Research Farm, assays were conducted 2,174d and 2,259d post application. For each assay, 320 samples were collected, soil cores were then returned to the laboratory and bio-assayed using a standard technique with wax moth larvae as an indicator for the presence of biocontrol nematodes in the sample.

We were unable to conduct a soil assay at the Stokoe Farm site during the project due to mandates concerning travel dictated by Cornell University.

Documenting Root Damage. Evaluation for feeding damage by CRW larvae within the continuous corn plots was only done at the Musgrave Research Farm, Popular Ridge, NY. Root damage assessment began August 6th, 2020. Researchers visited the site where corn roots were labeled, (Untreated & Treated Blocks), then dug out of each replicated block for each nematode treatment; blocks planted with Cry 3bb1 trait were not used in data analysis in 2020. Each variety within a replicated block had 10 corn roots removed (80 per block-40 in between rows and 40 from inside the tents), washed and evaluated for feeding damage using the Iowa scale. A similar assessment was conducted within the untreated replicates as well. The number of corn roots was pre-determined before arriving based on previous analysis parameters. Corn roots were removed (60 per block-30 in between rows and 30 from inside the tents) from each variety in the comparison plot (non-treated nematode) and evaluated for feeding damage using the Iowa scale.

Corn roots were then washed, evaluated, and rated for feeding damage using the Iowa scale (0-3 scale) at the Musgrave Research Farm on August 7th, 2020. Root ratings were conducted in a double blind format; the rating information was recorded.

CRW Emergence Evaluation. Similar to 2019, to determine if the presence of bio-control nematodes impact the number of emerging adults, the emerging adults were collected once again in 2020 using Coleman 10' x 10' screen tents. A single, Coleman 10' x 10' screen tent were erected in the corn plots located at Musgrave Research Farm, prior to the anticipated adult CRW emergence around mid-July. The process to set up these screen tents began on July 6th; a single Coleman 10' x 10' screen tent were placed over the Steinernema sp. variety x treatment x replication. All screen tents (total of 12) were set up by July 8th. Researchers determined that the evaluation on the Steinernema feltiae and Hetrorhabditis bacteriophora treated areas would not occur in 2020, due to significant cross contamination within that previously treated section from farm equipment. Going forward with an evaluation using current methods, assay work and root evaluation, would not be useful and relevant to the current project.

An additional study on non-nematode treated corn using the same varieties was conducted in parallel plot to the main research plot. Those corn rows also had single Coleman 10' x 10' screen tents added to collect any surviving adult CRWs. All screen tents (total of 9) were set up by July 6th.

Observations for CRW adult emergence began on July 14, 2020. Cages were checked for adults 1-2X week for nine weeks.  Adults collected from the tents were placed in alcohol, then returned to Cornell University until personnel were able to record results.  The number of adults collected during an observation were recorded.

Established Demonstration Plots.

2021

For the 2021 reporting period, the demonstration site located at the Musgrave Research Farm, Popular Ridge, NY was the only site accessible to the Shields’ Lab to conduct research activities. The entire field was planted to corn on May 17th, 2021.

Year 3 Demonstration Sites - For 2021, the goal of the Shield’s Lab was to recruit 5-10 new locations whose farmers would treat a single field with untreated check strips using one of two application methods: common pesticide sprayers or liquid manure. Typically, recruitment is done during the winter meeting cycle, however COVID-19 restrictions continued to limit the in-person meetings. The Shields’ Lab once again relied on using extension agents and consultants to reach potential new farms. In addition, multiple Zoominars were recorded and made available to interested growers.

Pesticide Sprayers. The current recommended application method of biocontrol nematodes is to rinse nematodes with high volumes of water through fine mesh screens into a holding tank. The nematode solution is then dumped into a field sprayer equipped with streamer nozzles or drop tubes.  The nematodes are then field applied using high volumes of water, 50 gallons or more per acre. The following farms adhered to the multi-species approach, two native NY strains of biocontrol entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)) in establishing their demonstration plots in 2021:

  • Village View Farm, Castorland, NY, owned and operated by Merv Moser. Field trial was established in a 75-acre field and will be in continuous corn for a minimum of 3-years
  • Zehr Farm, Lowville, NY, owned and operated by Roger Zehr. Field trial was established in an 80-acre field and will be in continuous corn for a minimum of 3-years
  • Doubledale Farm, Mannsville, NY, owned and operated by Dan Rossitter. Field trial was established in a 150-acre field and will be in continuous corn for a minimum of 3-years
  • Table Rock Farm, Castile, NY, owned and operated by Meghan Hauser. Two separate field trials were established in 230 acres and will be in continuous corn for a minimum of 3-years
  • Celtic Acres, Lowville, NY, owned and operated by John O’Brien. Field trial was established in a 20-acre field and will be in continuous corn for a minimum of 3-years
  • Irish Settlement Farm, owned and operated by Steve O’Brien. Field trial was established in a 28-acre field and will be in continuous corn for a minimum of 3-years
  • Moser Farm, owned and operated by Dean Moser. Field trial was established in a 65-acre field and will be in continuous corn for a minimum of 3-years

Liquid Manure Applications. There were no additional farms for 2021 that chose to apply bio-control nematodes using the liquid manure application method.

Tracking EPNs. Only the demonstration site at the Musgrave Research Farm was assayed during Year 3 to track persistence and population levels in the existing demonstration plots. At Musgrave Research Farm, assays were conducted 2,500d and 2,655d post application. For the spring assay evaluation (2,500d), a total of 20-samples were removed from the 0.5ac untreated section and 80-samples were removed from the 0.8ac treated section on April 28, 2021. Pre-winter soil sampling and bioassays to document EPN persistence at the two locations which have been in continuous corn since 2014 were assayed this fall to determine persistence levels and to check for non-EPN presence in the untreated plots. A total of 80-samples were removed from the 0.5ac untreated section and 120-samples were removed from the 0.8ac treated section on September 20, 2021.

A spring assay to verify bio-control nematode populations at the Stokoe Farm, was not attempted due to mandates limiting travel and research in the spring. A fall assay was also not an option as the farmer had not harvested by the end of October to allow researchers access to the field site to conduct soil assays.

Documenting Root Damage. Evaluation for feeding damage by CRW larvae within the continuous corn plots was only done at the Musgrave Research Farm, Popular Ridge, NY. Root damage assessment began August 11th, 2021. Researchers visited the site where corn roots were labeled, (Untreated & Treated Blocks), then dug out of each replicated block for each nematode treatment. The number of corn roots was pre-determined before arriving based on previous analysis parameters. Each treated replicated block was divided in two, then had corn roots removed (120 per block-60 per half). The 480 corn roots were then washed and evaluated for feeding damage using the Iowa scale. A similar assessment was conducted within the untreated replicates beginning on August 13th, 2021. Each replicated block was divided in two then had 480 corn roots removed (120 per block-60 per half). These untreated corn roots were then washed and evaluated for feeding damage using the Iowa scale. Root ratings were conducted in a double-blind format; the rating information was recorded.

CRW Emergence Evaluation. Screen tents used in 2019 and 2020, were not erected in the corn plots located at Musgrave Research Farm during the 2021 growing season. Researchers determined that the evaluation at the site was not necessary this final year.  This decision was made due to the lack of available labor due to COVID-19 restrictions to erect the screen tents. Furthermore, Elson Shields was confident that enough data had been collected concerning adult emergence at this continuous corn location.

Research results and discussion:

Vermont

2019 (Year 1)

Borderview Farm

Soil Assays. The initial soil evaluation prior to EPN application found that <1% of the samples were positive for a native EPN. The establishment assay, conducted 40d post application found that both Steinernema sp. are present at levels higher than normally found for an establishment assay. The four Steinernema sp. combination blocks assayed resulted in; 41% of the samples positive for S. carpocapsae and 54% positive for S. feltiae respectively. The site was assayed again in the fall after corn harvest, 120d post application. The four Steinernema sp. combination blocks assayed resulted in; 31% of the samples positive for S. carpocapsae and 35% positive for S. feltiae respectively. These results may not accurately represent the population found by these soil assays, as the researchers conducting them feel that a portion could be false-positives. The factors leading to this conclusion are; multiple individuals were interpreting the results for the first time and unfamiliarity in determining the cadavers were killed by EPNs.

Adult Emergence

Borderview Farm

 

 

 

Total Adults Found

 

Males

Females

 

NE

SW

NE

Sw

Control Plots

478

244

1,625

560

 

 

 

 

 

EPN Treated Plots

528

300

1,689

1,120

Root Damage

Borderview Farm

 

 

 

Mean

Standard Error

Control Plots

0.08

0.01

EPN Treated Plots

0.12

0.06

Results show no significant difference in Year 1 between the untreated and treated plots.

Bridgeman View Farm

Soil Assays. The establishment assay, conducted 50d post application found that Steinernema carpocapsae was at a level typically representative for this assay timing, while Steinernema feltiae, was at a level lower than normally found for an establishment assay. The four Steinernema sp. combination blocks assayed resulted in; 6% of the samples positive for S. carpocapsae and 14% positive for S. feltiae respectively. The site was assayed again in the fall after corn harvest, 150d post application. The four Steinernema sp. combination blocks assayed resulted in; 18% of the samples positive for S. carpocapsae and 36% positive for S. feltiae respectively. These results, while more representative of a fall assay however may not accurately represent the population found by these soil assays. Similar to the assays at Borderview Farm, the researchers conducting them feel that a portion could be false-positives. The factors leading to this conclusion are; multiple individuals were interpreting the results for the first time and unfamiliarity in determining the cadavers were killed by EPNs.

2020 (Year 2)

Borderview Farm

Soil Assays. An assay was conducted 290d post application to verify bio-control nematodes had over-wintered and were persisting within the demonstration site. Results from the spring evaluation showed a reduction in previously reported levels of both Steinernema sp. applied there. In the fall, there was concern that the results may have been inaccurate. To help clear up any concerns over what was being evaluated, the Shields’ Lab sent infected cadavers to the UVM Extension NWCS Team to guide in identifying cadavers that may have been killed by either Steinernema sp. The four Steinernema sp. combination blocks assayed resulted in; 8% of the samples positive for S. carpocapsae and 12% positive for S. feltiae respectively. The S. carpocapsae numbers are not unexpected, most assays the results range from 0-10%, experience has shown that the nematode will disappear and reemerge in later years depending on soil conditions generally. The S. feltiae results are significantly below average, typically in the 25-40% range, but difficult to determine if a result of the individual recording the results or a true representation of what was in the soil. The site was assayed again in the fall after corn harvest, 484d post application. The four Steinernema sp. combination blocks assayed resulted in; 37% of the samples positive for S. carpocapsae and 23% positive for S. feltiae respectively. These results signify that the bio-control nematodes are present, persisting and consistent with past studies over multiple years within New York agricultural fields. According to the Vermont researchers, in June 2022, the fluctuations in assay results were most likely due to inconsistent sample collection, handling and bioassay procedures.  In addition, site contamination resulted in poor communications with the farm staff and the untreated plots were tilled crossways with the inoculated plots resulting in the movement of persistent EPNs into the untreated plots.

Adult Emergence

Borderview Farm

 

 

 

 

Total Adults Found

 

Control NE

Control SW

EPN NE

EPN SW

2019

2,103

804

2,217

1,420

2020

2,746

2,979

2,694

2,935

Root Damage

Borderview Farm-2019-2021

CRW Root Rating Evaluation

Control Plots

Nematode Treated Plots

 

Mean ± SE

Mean ± SE

2019

.08 ± .01

.12 ± .06

2020

.06 ± .02

.01 ± .02

Results show no significant difference in Year 2 between the untreated and treated plots.

Bridgeman View Farm

Soil Assays. An assay was conducted 330d post application to verify bio-control nematodes had over-wintered and were persisting within the demonstration site. Results from the spring evaluation showed a reduction in previously reported levels of both Steinernema sp. applied there. In the fall, there was concern that the results may have been inaccurate. To help clear up any concerns over what was being evaluated, the Shields’ Lab sent infected cadavers to the Lewins’ Lab to guide in identifying cadavers that may have been killed by either Steinernema sp. The four Steinernema sp. combination blocks assayed resulted in; 2% of the samples positive for S. carpocapsae and 6% positive for S. feltiae respectively. The S. carpocapsae numbers are not unexpected, most assays the results range from 0-10%. The S. feltiae results are significantly below average, typically in the 25-40% range, but difficult to determine if a result of the individual recording the results or a true representation of what was in the soil. The site was assayed again in the fall after corn harvest, 523d post application. The four Steinernema sp. combination blocks assayed resulted in; 22% of the samples positive for S. carpocapsae and 28% positive for S. feltiae respectively. These results signify that the bio-control nematodes are present and persisting. According to the Vermont researchers, in June 2022, the fluctuations in assay results were most likely due to inconsistent sample collection, handling and bioassay procedures.  In addition, site contamination resulted in poor communications with the farm staff and the untreated plots were tilled crossways with the inoculated plots resulting in the movement of persistent EPNs into the untreated plots.

2021 (Year 3)

Borderview Farm

Soil Assays. The goal was to do a spring 2021 soil assay to evaluate the long-term persistence of biocontrol nematodes verifying biocontrol nematodes had over-wintered and were persisting within the demonstration site. However, the research plots were accidently worked up with a disc in preparation of the spring planting. In Year 1 & 2, planting protocols indicated that the research plots were to be no tilled in the spring starting with the control plots and ending in the nematode treated plots to avoid contamination. Due to accidental discing of the research plots, researchers needed to determine how much contamination may have occurred within the control plots. Researchers discussed and decided to plant the corn as planned and then sample the untreated plots for any presence of biocontrol nematodes to document any contamination. Results found by the assay would determine the course of action in these plots for a fall bioassay, root evaluation, and adult collection of emerging corn rootworm. An assay was conducted 740d post application within the untreated plots at Borderview Farm. Samples were evaluated at the University of Vermont by the UVM Extension NWCS Team using the protocols developed by the Shields’ Lab at Cornell University. Results from the spring evaluation within the untreated research plots showed little or no contamination within the untreated plots. While the intention was to return and try and assay the treated plots, the UVM Extension NWCS Team after further discussions with the Shields' Lab determined the spring assay results were sufficient; contamination was not present in untreated plots and significant population changes are not expected in treated sections based past studies over multiple years within NY agricultural fields. The site was assayed again in the fall after corn harvest, 880d post application. The four Steinernema sp. combination blocks assayed resulted in; 34% of the samples positive for S. feltiae while none of the samples showed evidence of S. carpocapsae. These results signify that the bio-control nematodes are present and persisting. The fluctuation in assay results over the three-year period is most likely due to the individuals interpreting these results. The results fall in the expected ranges for both species after multiple years of persistence in the soil. According to the Vermont researchers, in June 2022, the fluctuations in assay results were most likely due to inconsistent sample collection, handling and bioassay procedures.  In addition, site contamination resulted in poor communications with the farm staff and the untreated plots were tilled crossways with the inoculated plots resulting in the movement of persistent EPNs into the untreated plots

Adult Emergence.

Borderview Farm 2019-2021

CRW Adult Emergence

 

 

Total Adults Found

 

Control NE

Control SW

EPN NE

EPN SW

2019

2,103

804

2,217

1,420

2020

2,746

2,979

2,694

2,935

2021

2,246

1,554

2,186

1,833

Root Damage.

Borderview Farm-2019-2021

CRW Root Rating Evaluation

Control Plots

Nematode Treated Plots

 

Mean ± SE

Mean ± SE

2019

.08 ± .01

.12 ± .06

2020

.06 ± .02

.01 ± .02

2021

.35 ± .07

.05 ± .09

Results show a significant difference in Year 3 between the untreated and treated plots.

Bridgeman View Farm

Soil Assays. An assay was conducted in the fall after corn harvest, 880d post application to verify bio-control nematodes were persisting within the demonstration site. Results from the fall evaluation showed a more consistent picture of the nematode population within the research plots at the Bridgeman View Farm. The four Steinernema sp. combination blocks assayed resulted in; 40% of the samples positive for S. feltiae while none of the samples showed evidence of S. carpocapsae. These results signify that the bio-control nematodes are present and persisting. The fluctuation in assay results over the three-year period is most likely due to the individuals interpreting these results. The results fall in the expected ranges for both species after multiple years of persistence in the soil.

Pennsylvania

2019 (Year 1)

Larson Ag Research Farm

Soil Assays. The initial soil evaluation prior to EPN application found that 13% of the samples were positive for a previously applied commercial EPN (mid 90s application). The four Steinernema sp. combination blocks assayed resulted in; 8% of the samples positive for S. carpocapsae and 4% positive for S. feltiae respectively, also 1% of samples found Hetrorhabditis bacteriophora. The establishment assay, conducted 30d post application found that both Steinernema sp. are present at levels normally found for an establishment assay. The four Steinernema sp. combination blocks assayed resulted in; 1% of the samples positive for S. carpocapsae and 34% positive for S. feltiae respectively.

Adult Emergence

Larson Ag Research Farm

 

 

 

Total Adults Found

 

Males

Females

BT EPNs

73

95

Non-BT EPNs

33

51

BT No EPNs

394

745

Non-BT No EPNs

121

166

Root Damage

Larson Ag Research Farm

 

 

 

Mean

Standard Error

BT EPNs

0.71

0.03

Non-BT EPNs

0.61

0.06

BT No EPNs

0.79

0.08

Non-BT No EPNs

0.45

0.14

Results show no significant difference in Year 1 between the untreated and treated plots.

2020 (Year 2)

Larson Ag Research Farm

An assay was conducted 350d post application to verify bio-control nematodes had over-wintered and were persisting within the demonstration site. To assist the Tooker Lab in identifying cadavers killed by either Steinernema sp. or by Hetrorhabditis bacteriophora, the number of soil samples removed were doubled; half would be evaluated at the Tooker Lab, the other half at the Shields’ Lab. Samples were removed from each of the untreated and treated bio-control nematode plots. The samples at the Tooker Lab were evaluated too long after exposure and were not reliable. For the spring evaluation, the samples read by the Shields’ Lab found that the four Steinernema sp. combination blocks assayed resulted in; 0% of the samples positive for S. carpocapsae and 48% positive for S. feltiae respectively. The four non-EPN treated blocks showed evidence of contamination, resulting in 10% of the samples being positive for S. feltiae.

Post-harvest, an assay was conducted 526d post application to verify bio-control nematodes populations. Samples were collected and delivered to the Shields’ Lab for evaluation. For the fall evaluation, the samples read by the Shields’ Lab found that the four Steinernema sp. combination blocks assayed resulted in; 3% of the samples positive for S. carpocapsae and 49% positive for S. feltiae respectively. The four non-EPN treated blocks continued to show evidence of contamination, resulting in 1% of the samples being positive for S. carpocapsae and 15% positive for S. feltiae respectively.

Adult Emergence

Larson Ag Research Farm

 

 

 

 

Total Adults Found

 

Bt EPNs

Non-Bt, EPNs

Bt, No EPNs

Non-Bt, No EPNs

2019

168

84

1,139

287

2020

1,638

5,624

8,709

654

Root Damage

Larson Ag Research Farm-2019-2021

CRW Root Rating Evaluation

 

 

 

 

Bt Nematode

Non Bt-No Nematode

Non Bt-Nematode

Bt-No Nematodes

 

Mean ± SE

Mean ± SE

Mean ± SE

Mean ± SE

2019

.71 ± .03

.45 ± .14

.61 ± .06

.79 ± .08

2020

.89 ± .09

2.45 ± .03

2.34 ± .09

1.00 ± .08

Results show significant difference in Year 2 between the untreated and treated plots versus what was seen in 2019. This is a direct result of extreme drought conditions in June-August 2020 in Pennsylvania where the area received less than 2 inches of rain for nearly 2 months. This lack of moisture reduced the ability of nematodes to move around and find the corn rootworm larvae. As a result, there was no impact within the nematode treated plots and they suffered significant CRW damage.

2021 (Year 3)

Post-harvest, an assay was conducted 910d post application to verify biocontrol nematodes populations at the Larson Ag research Farm. Samples were collected and delivered to the Shields’ Lab for evaluation. For the fall evaluation, the samples read by the Shields’ Lab found that the four Steinernema sp. combination blocks assayed resulted in; 39% of the samples positive for S. feltiae while none of the samples showed evidence of S. carpocapsae. The four non-EPN treated blocks continued to show evidence of contamination, resulting in 10% positive for S. feltiae respectively. These results signify that the bio-control nematodes are present and persisting. The results fall in the expected ranges for both species within the treated areas after multiple years of persistence in the soil.

Adult Emergence.

 

Larson Ag Research Farm-2019-2021

CRW Adult Emergence

Total Adults Found

 

Bt EPNs

Non-Bt, EPNs

Bt, No EPNs

Non-Bt, No EPNs

2019

168

84

1,139

287

2020

1,638

5,624

8,709

654

2021

3,232

6,157

13,088

1,768

 Root Damage.

Larson Ag Research Farm-2019-2021

CRW Root Rating Evaluation

 

 

Bt EPNs

Non Bt-EPNs

Bt-No EPNs

Non Bt-No EPNs

 

Mean ± SE

Mean ± SE

Mean ± SE

Mean ± SE

2019

0.71 ± .03

0.61 ± .06

0.79 ± .08

0.45 ± .14

2020

0.89 ± .09

2.34 ± .09

1.00 ± .08

2.45 ± .03

2021

0.91 ± .04

1.80 ± .16

1.09 ± .04

1.71 ± .03

Schrack Farms

Nematode-induced mortality was very low with only two samples (one from the treated area [infected with S. carpocapsae], one from the untreated [infected with S. feltiae) yielding waxworms that were killed by nematodes. While this outcome was disappointing, it was not surprising given that central Pennsylvania suffered from an extended drought during June-August.

2021 (Year 3)

Schrack Farms

Nothing to report from this site due to the farmer reclaiming the research plot acreage.

New York

2019 (Year 1)

Stokoe Farm

Soil Assays. The Stokoe Farm site was assayed 759d post application to verify multi-year persistence of EPNs. The four Steinernema sp. combination blocks assayed resulted in; 1% of the samples positive for S. carpocapsae and 35% positive for S.feltiae respectively. Bioassays were also conducted in the four untreated blocks; the assay resulted in 0% of the samples positive for either Steinernema sp. species.

Musgrave Research Farm

Corn varieties. At this site, researchers will plant one non-traited corn rootworm variety and three - commercially available GMO-Bt-corn rootworm  varieties within each EPN treated continuous corn plot. The same four varieties will be planted in the untreated continuous corn blocks.

Corn Variety Trait Specific Variety Identifier
Conventional non-Bt-corn rootworm traited corn CONV
Yield Gard Pro single trait GMO-Bt-corn rootworm traited corn 3bb1
Herculux single trait GMO-Bt-corn rootworm traited corn 34-35
SmartStax Pro dual (pyramid) trait GMO-Bt-corn rootworm traited corn SS

Soil Assays. The Musgrave Research Farm site assays were conducted 1,816d and 1,877d post application to verify multi-year persistence of EPNs. The four Steinernema sp. combination blocks assayed resulted in; 1% of the samples positive for S. carpocapsae and 39% positive for S.feltiae respectively (1,816d). The four Steinernema sp. combination blocks assayed resulted in; 1% of the samples positive for S. carpocapsae and 39% positive for S.feltiae respectively. Bioassays were also conducted in the four S.feltiae and H. bacteriophora combination blocks. The assay resulted in 41% of the samples positive for S.feltiae and 0% positive for H. bacteriophora (1816d). For the pre-harvest assay (1877d), sampling was conducted within area covered by screen tents and outside in the area near where roots were removed for damage assessment. The four Steinernema sp. combination blocks assayed resulted in; 0% of the samples positive for S. carpocapsae and 35% positive for S.feltiae respectively in the outside area, 0% of the samples positive for S. carpocapsae and 41% positive for S.feltiae respectively in the outside area covered by the screen tents.

Adult Emergence. The following tables summarizes the number of corn rootworm adults found and collected throughout the untreated and treated Steinernema sp. blocks located at Musgrave Research Farm.

2019-Aurora

Totals

 

 

Totals

 

 

Males-NonEPN

Conv

639

 

Males-Sc/Sf

Conv

693

 

3Bb1

238

 

 

3Bb1

305

 

34-35

359

 

 

34-35

190

 

SS

97

 

 

SS

149

Females-NonEPNs

Conv

7512

 

Females-Sc/Sf

Conv

8200

 

3Bb1

6406

 

 

3Bb1

4071

 

34-35

4943

 

 

34-35

3007

 

SS

955

 

 

SS

1644

Root Damage. The following tables summarizes the damage to selected corn plants from corn rootworm larvae within the untreated and treated Steinernema sp. blocks along with a comparison within the screen tents located at Musgrave Research Farm. 

Aurora-2019

Sc & Sf EPN Combo

Sc & Sf EPN Comb

 

Outside Tents

Inside Tents

 

Mean

SE

Mean

SE

Conventional Corn

.25

.11

1.62

.14

 34/35

.12

.05

.95

.14

SmartStax

.10

.01

.13

.04

3Bb1

.20

.07

.72

.08

 

 

 

 

 

 

Untreated variety

Untreated variety

 

Outside Tents

Inside Tents

 

Mean

SE

Mean

SE

Conventional Corn

.49

.13

2.13

.07

34/35

1.13

.2

1.87

.14

SmartStax

.10

0

.15

.02

3Bb1

.10

0

.36

.08

Liquid Manure Fields

Soil Assays. Post application, establishment assays were conducted in 12 fields, the remaining fields, due to weather, and late harvest were not sampled in Year 1.

2019

% EPN Positive Soil Samples – NNY Manure Trials

Location

Sc

Sf

Hb

Combo

Marks–Left Side

6±4

35±5

0±0

41±9

Marks-Middle Row

2±2

28±7

0±0

30±6

Marks-Right Side

0±0

37±4

0±0

37±4

Demko Site 1-Left Side

0±0

25±4

0±0

25±4

Demko Site 1-Middle Row

2±2

32±6

0±0

33±7

Demko Site 1-Right Side

0±0

28±3

0±0

28±3

Demko Site 2-Left Side

1±2

38±0

0±0

39±2

Demko Site 2–Middle Row

4±2

31±0

0±0

35±2

Demko Site 2-Right Side

3±3

39±0

0±0

42±3

Kiechle-Right Side

3±2

30±3

0±0

33±3

Kiechle-Left Side

0±0

26±3

0±0

26±3

Eastman-Field 1

1±1

37±6

0±0

38±6

Eastman-Field 2

0±0

29±4

0±0

29±4

Reed–Left Side

0±0

34±1

0±0

34±1

Reed–Middle Row

0±0

24±1

0±0

24±1

Reed–Right Side

0±0

34±1

0±0

34±1

Ferry–Left Side

0±0

26±1

0±0

26±1

Ferry–Middle Row

4±4

48±3

0±0

52±7

Ferry–Right Side

2±3

28±1

0±0

30±4

Horst-Row 1

0±0

37±0

0±0

37±0

Horst-Row 2

0±0

36±0

0±0

36±0

Murray-Row 1

0±0

36±0

0±0

36±0

Murray-Row 2

0±0

27±0

0±0

27±0

Bast-Row 1

0±0

29±1

0±0

29±1

Robbins–Left Side

0±0

34±1

0±0

34±1

Robbins-Middle Row

0±0

33±1

0±0

33±1

Robbins–Right Side

0±0

37±0

0±0

37±0

Our results have demonstrated that biocontrol nematodes can be effectively applied to fields via liquid manure as the carrier and delivery method.  The next step in this process will be to continue in 2020.  We need to determine the lowest possible number of biocontrol nematodes that can be applied per acre with manure and still achieve successful establishment. 

2020 (Year 2)

Musgrave Research Farm

Corn varieties. At this site, researchers will plant one non-traited corn rootworm variety and three - commercially available GMO-Bt-corn rootworm varieties within each EPN treated continuous corn plot. The same four varieties will be planted in the untreated continuous corn blocks.

Corn Variety Trait Specific Variety Identifier
Conventional non-Bt-corn rootworm traited corn CONV
Yield Gard Pro single trait GMO-Bt-corn rootworm traited corn 3bb1
Herculux single trait GMO-Bt-corn rootworm traited corn 34-35
SmartStax Pro dual (pyramid) trait GMO-Bt-corn rootworm traited corn SS

Soil Assays. The Musgrave Research Farm site spring assays were conducted 2,174d and 2,189d post application to verify multi-year persistence of EPNs (continuous corn and combination blocks respectively). The four Steinernema sp. continuous corn blocks assayed resulted in; 0% of the samples positive for S. carpocapsae and 41% positive for S.feltiae respectively. The four Steinernema sp. combination blocks assayed resulted in; 0% of the samples positive for S. carpocapsae and 28% positive for S.feltiae respectively. Bioassays were also conducted in the four S.feltiae and H. bacteriophora continuous corn and combination blocks. The assay resulted in 22% of the samples positive for S.feltiae and 1% positive for H. bacteriophora (continuous corn) and 26% of the samples positive for S.feltiae and 2% positive for H. bacteriophora (combination).

A pre-harvest soil assay was conducted 2,259d within the four Steinernema sp. continuous corn blocks. Samples were removed from, 1) the area covered by screen tents, and 2) outside in the area near where roots were removed for damage assessment. The four Steinernema sp. continuous corn blocks assayed resulted in; 0% of the samples positive for S. carpocapsae and 36% positive for S.feltiae respectively in the outside area, 0% of the samples positive for S. carpocapsae and 30% positive for S.feltiae respectively in the area covered by the screen tents. Samples were also removed from the four S.feltiae and H. bacteriophora continuous corn blocks near the area where roots were removed for damage assessment. The assay resulted in 32% of the samples positive for S.feltiae and 3% positive for H. bacteriophora.

Adult Emergence. The following tables summarizes the number of corn rootworm adults found and collected throughout the untreated and treated Steinernema sp. blocks located at Musgrave Research Farm in 2020.

2020-Aurora

Non EPN Treated Blocks

Adults Collected

3-Tents/Variety

Sc & Sf Treated Blocks

Adults Collected

4 -Tents/Variety

Bt Corn Varieties

Total

Mean/ Tent

SE/Tent

Total

Mean/Tent

SE/Tent

Conventional

4,227

1,409

353

3,559

890

194

34-35

4,274

1,425

379

3,746

937

285

SmartStax

695

232

35

2,363

591

145

Root Damage. The following tables summarizes the damage to selected corn plants from corn rootworm larvae within the untreated and treated Steinernema sp. continuous corn blocks along with a comparison within the screen tents located at Musgrave Research Farm. In addition, roots were dug from within the treated S.feltiae and H. bacteriophora continuous corn blocks.

Aurora – 2020

Sc & Sf EPN Combo

Sc & Sf EPN Combo

 

Outside Tents

Inside Tents

 

Mean

SE

Mean

SE

Conventional Corn

.08

.03

.13

.03

34/35

.17

.15

.29

.12

SmartStax

.07

.01

.10

.02

3Bb1

.10

.03

-

-

 

 

 

 

 

 

Untreated variety

Untreated variety

 

Outside Tents

Inside Tents

 

Mean

SE

Mean

SE

Conventional Corn

.64

.25

.68

.26

34/35

.83

.24

1.39

.08

SmartStax

.09

.01

.07

.02

3Bb1

.77

.23

-

-

 

 

 

 

 

 

Sf & Hb EPN Combo

 

 

 

No Tents

 

 

 

Mean

SE

 

 

Conventional Corn

.84

.25

 

 

34/35

1.14

.07

 

 

SmartStax

.10

.01

 

 

3Bb1

.16

.04

 

 

2021 (Year 3)

Musgrave Research Farm

Corn varieties. At this site, researchers will plant one non-traited corn rootworm variety and one GMO-Bt- corn rootworm variety within each EPN treated continuous corn plot. For each one variety, one planted row will have no seed treatment and a second row will have an insecticide treatment. The same four varieties will be planted in the untreated continuous corn blocks.

Corn Variety Trait Specific Variety Identifier
Conventional non-Bt-corn rootworm no seed treatment

Untreated RW Bt

Conventional non-Bt-corn rootworm insecticide treated seed

Untreated non Bt

SmartStax Pro dual (pyramid) trait GMO-Bt-corn rootworm traited corn no seed treatment

Treated RW Bt

SmartStax Pro dual (pyramid) trait GMO-Bt-corn rootworm traited corn insecticide treated seed

Treated non Bt

Soil Assays. The Musgrave Research Farm site spring assay was conducted 2,500d post application to verify multi-year persistence of EPNs within the continuous blocks, untreated and treated respectively. The four Steinernema sp. continuous corn blocks assayed resulted in; 0% of the samples positive for S. carpocapsae and 65% positive for S. feltiae respectively. Positive samples may be higher than they are typically (20-40%) as a different individual interpreted the samples from this assay. The results however indicate that the nematodes are continuing to persist after seven growing seasons.

A pre-harvest soil assay was conducted 2,655d within the four Steinernema sp. continuous corn blocks. Samples were removed from the untreated and treated section replicates at the farm. There was no evidence of biocontrol nematodes within the samples removed from untreated replicates. The four Steinernema sp. continuous corn blocks assayed resulted in; 0% of the samples positive for S. carpocapsae and 37% positive for S. feltiae respectively. The results fall in the expected ranges for both species within the treated areas after multiple years of persistence in the soil.

Root Damage. The following tables summarizes the damage to selected corn plants from corn rootworm larvae within the untreated and treated Steinernema sp. continuous corn blocks.

Aurora - 2021

Untreated Continuous Corn

Treated Continuous Corn

CRW

Mean

STD

SE

Mean

STD

SE

Untreated RW Bt

0.85

1.18

0.59

0.32

0.17

0.09

Untreated non Bt

1.92

0.48

0.24

1.73

0.08

0.04

Treated RW Bt

0.33

0.27

0.14

0.32

0.12

0.06

Treated non Bt

0.27

0.05

0.02

0.24

0.08

0.04

Research conclusions:

Corn rootworm larvae have few natural soil predators, and when rootworm populations increase, as in continuous corn systems, these natural enemies cannot keep populations below economic levels. The Shields's Lab in cooperation with researchers from the University of Vermont and Penn State, have shown the ability of biocontrol nematodes to persist in continuous corn for multiple growing seasons from a single application.  Furthermore, the research shows the compatibility with the Bt-RW technology currently available in corn varieties. In addition to persisting for several years after a single application, the data shows persistent biocontrol nematodes can persist across crop rotations providing multiple years in multiple fields.

Adoption of this technology is an important new management strategy growers can use that is completely independent of other management tactics. While the current delivery system to the farmer/applicator has been met with positive feedback, the current entomopathogenic nematode (EPN) formulation is inconvenient and labor intensive for the farmer/applicator to prepare/process the biocontrol nematodes for field applications.  Additionally, EPNs in the current delivery system have a shelf life of only 72-96 hours. The current  shelf life of 72-96 hours after EPN production is complete requires precise planning and having all the pieces in place for a timely successful field application. Rain delays and labor issues complicates the planning process and increasing the shelf life and a more user-friendly formulation, removes a lot of the complexities involved with timely EPN production and field application. This project has shown that a more user-friendly formulation with an extended shelf life would increase wider acceptance among producers and commercial applicators. 

The research has shown this technology to be an affordable biological control strategy that is focused on soil insects that will reduce damage/losses, is convenient to apply, and results in restoration of yield across treated locations within impacted fields. Improving the current delivery system we expect will also result in increased adoption. 

 

Participation Summary
30 Farmers participating in research

Education

Educational approach:

2019-During Year 1 (2019) of this study, collaborators focused on recruitment of farmers and establishing demonstration plots in PA and VT. In NYS, educational approaches focused on further dissemination of previous results and the opportunities to provide bio-control through various application methods.

2020-In the second year of the study (2020), research milestones related to our educational approach to this project in regards to additional demonstration plots and documentation of bio-control nematode establishment/persistence was limited or restricted due to the global COVID-19 pandemic. Efforts to produce materials and media continued in 2020 as the Shields Lab produces three different articles relating to corn rootworm control using bio-control nematodes.

UPDATE June 2022 –

An article was published in the mid-February 2020 Progressive Farmer titled:

“Crop Invaders: Invasion of the Rootworm Snatchers.”

Two articles appeared this year in What’s Cropping Up? to promote the use of biological control nematodes.

On October 2, 2020, an article appeared in What’s Cropping Up? titled:

“Are Persistent Biocontrol nematodes (Entomopathogenic) an economic benefit for your NY farm?”

On November 13, 2020, an article appeared in What’s Cropping Up? titled:

“Managing Corn Rootworm in NY to delay Bt resistance (& save seed costs)”

One additional article was released on November 11, 2020, on the Northern New York Agricultural Development Program website titled:

“Are Persistent Biocontrol Nematodes (entomopathogenic) an Economic Benefit for Your Northern NY Farm?”

2021 - The final year of the study (2021), research milestones related to our educational approach to this project regarding additional demonstration plots and documentation of bio-control nematode establishment/persistence continued to be limited or restricted due to the COVID-19 pandemic. Researchers at the University of Vermont and Cornell University were able to recruit additional farms for this study. At Penn State, COVID-19 restrictions prohibited recruitment of new growers for 2021.

Efforts continued in 2021 by researchers in producing and providing materials and media articles relating to corn rootworm control using bio-control nematodes. In addition to the articles, multiple Zoominars on the research were conducted and fields days at two research farms were also held. 

Shields, E. J. and A. M. Testa.  2021.  Biological Control of Corn Rootworm with Persistent Entomopathogenic Nematodes.  J. Econ Entomol.  (in review).

Biocontrol of Corn Rootworm with persistent EPNs in NY presented by Elson Shields (45 minutes) on January 6, 2021 via Zoominar for Cornell Cooperative Extension Agents - Audience: 25

Research Results using Persistent Entomopathogenic Nematodes for Corn Rootworm Control.  https://www.youtube.com/watch?v=_bk9--8cfC8&feature=youtu.be.  2/17/21.

“What are Persistent Biocontrol Nematodes.” YouTube,18 Feb. 2021https://youtu.be/7QQlKI41_Lo

An article was published in March 2021 Progressive Dairy titled:

“Biological control of corn rootworm with native N.Y. entomopathogenic nematodes.”

Corn Rootworm Resistance to GMO traits & their Biological Control.  Farm Credit East hosted Zoominar 4/7/2021

Cornell Cooperative Extension Agent Training - Seed Corn Maggot & Biological Control of Corn Rootworm (via Zoominar) on 11/16/2021, Audience: 25 

Cornell Cooperative Extension Agent & Dealer Meeting - Seed Corn Maggot & Biological Control of Corn Rootworm (via Zoominar) on 12/01/2021, Audience: 137

Milestones

Milestone #1 (click to expand/collapse)
What beneficiaries do and learn:

1) 800 corn growers in NY, PA and VT first learn of the project and performance target at 2019 summer crop meetings. Farmers will also hear about the project through our outreach networks including social media and newsletters encouraging adoption (>9000). (Dec 2019).

Proposed number of farmer beneficiaries who will participate:

800

Actual number of farmer beneficiaries who participated:

437

Proposed Completion Date:

December 31, 2019

Status:

Completed

Date Completed:

December 31, 2019

Accomplishments:

2019-Year 1

Vermont. A presentation was made at the NWCS Annual Field Day on July 25, 2019 held at Borderview Farm, in Alburgh, VT. During the presentation to 237 attendees, information on the project goals and preliminary results was shared.

Pennsylvania. A detailed summary of the NESARE project, its methods and expected results was provided by John Tooker at the Penn State Agronomic Diagnostic Clinic, Penn State Extension Field Day, held July 16 & 17, 2019 in Rockspring, PA to 100 attendees.

New York. Elson Shields provided a summary and update on the continuing research of EPNs for CRW control at the Aurora Field Day held at Musgrave Research Farm on July 11, 2019. During the tour stop, Elson was able to demonstrate how EPNs are applied to field plots, show screen tents within research blocks, and answer questions regarding the project. Throughout the day, 100 individuals stopped by the research site.

Milestone #2 (click to expand/collapse)
What beneficiaries do and learn:

2) Nine farmer collaborations (3 per state) will assist with the development of demonstration trials to evaluate the biocontrol practice in multiple environments comparing organic and non-GM corn systems. (Dec 2019)

Proposed number of farmer beneficiaries who will participate:

9

Actual number of farmer beneficiaries who participated:

13

Proposed Completion Date:

December 31, 2019

Status:

Completed

Date Completed:

December 31, 2019

Accomplishments:

2019-Year 1

Thirteen collaborators participated in the establishment of demonstration trials for this NE-SARE project.

In Pennsylvania, a single farm collaborator assisted in the development of demonstration plots to evaluate the EPNs in organic and non-GM corn systems. Having the past years’ experience to work off, and a winter meeting cycle to promote the project, both state coordinators feel the following years will be easier to recruit farms to participate.

UPDATE JUNE 2022  - Recruitment of farms was restricted due to the onset of the global pandemic. Penn State mandated restrictions due to COVID-19 prevented enrollment of additional farmers for 2020 & 2021.

Vermont had two farm collaborators who assisted in the development of demonstration plots to evaluate the EPNs in organic and non-GM corn systems.

UPDATE JUNE 2022 - A third collaborator was added in 2021, Island dairy established a 10ac field during the final year of the project.

New York collaborations are much easier to identify based on the extensive visibility of the research conducted by the Shields’ Lab and the extension resources available throughout the corn growing counties in NYS. During 2019, the Shields’ Lab was able to add a total of ten new collaborators; adopters of biological control in corn for corn rootworm through liquid manure applications.

Collaboration amongst New York farms willing to adopt the EPN technology continued despite restrictions mandated by Cornell University and New York State. Nine additional farms using the multi-species approach applied EPNs using pesticide sprayers. Unfortunately, no new farms will willing to try the liquid manure application method in 2020 or 2021.

Milestone #3 (click to expand/collapse)
What beneficiaries do and learn:

3) Three growers will be recruited via existing Extension networks in VT and PA to host the various demonstration plots. Plots will be established in continuous corn fields with a minimum of 3 years remaining in conventional production and 2 years in organic production before rotation to another crop. (Dec 2019, Dec 2020). (Note: In NY, those sites are already established and have been providing data to support this proposal.)

Proposed number of farmer beneficiaries who will participate:

6

Actual number of farmer beneficiaries who participated:

4

Proposed Completion Date:

December 31, 2021

Status:

Completed

Date Completed:

December 31, 2021

Accomplishments:

2019-Year 1

Thirteen new growers were recruited in 2019, Year 1 of the NE-SARE project.

A single grower was recruited in Pennsylvania, while two were found in Vermont using extension networks to host a demonstration site. Plots were established in continuous corn fields and will remain in conventional production throughout the current project. Building on the successes of 2019, both state coordinators feel the following years will be easier to recruit farms to participate.

As noted in the milestone, NYS sites have already been established and continue to provide data to support the proposal. Despite that, the Shields's Lab was able to find 10 new farms in 2019 to participate.

2020-Year 2

Due to restrictions on research and travel mandated by The University of Vermont and Penn State University, due to the global pandemic, the UVM Extension NWCS Team and Tooker Lab were unable to recruit in 2020. The plan for 2021 (year 3), if allowed, will resume recruitment of growers via existing Extension networks. Although the milestone states that any new demonstration sites shall remain in either a conventional production for 3 years or in an organic production for 2 years before rotation to another crop, researchers will continue pursuing new collaborators despite the loss of the 2020 field season.

2021-Year 3

Restrictions on research and travel continued to some degree because of the COVID-19 pandemic hindering recruitment of new growers.

A single grower was recruited in Vermont using extension networks to host a demonstration site. Plots were established in continuous corn fields and will remain in conventional production beyond the current project.

UPDATE JUNE 2022 - Recruitment of farms was restricted due to the onset of the global pandemic. All three universities had mandated restrictions due to COVID-19 which limited enrollment of additional farmers for 2020 & 2021.

University of Vermont researchers and the Shields' Lab will continue to monitor any reduction in stand loss and/or yield increases with the cooperating farms.

Milestone #4 (click to expand/collapse)
What beneficiaries do and learn:

4) Biocontrol nematode establishment from a single inoculation in year 1 will be documented 30-45 days after inoculation and at the end of the season. In years 2 & 3, nematode persistence will be documented at the beginning and the end of each growing season. Documentation of the continued persistence in the NY plots will be continued. All sites will be evaluated for damage from corn rootworm and other soil insects each year of the project. (Dec 2019, Dec 2020, Dec 2021).

Proposed number of farmer beneficiaries who will participate:

8

Actual number of farmer beneficiaries who participated:

7

Proposed Completion Date:

December 31, 2021

Status:

Completed

Date Completed:

December 31, 2021

Accomplishments:

2019-Year 1

In VT, demonstration plots were established at two different locations. Bio-control nematodes were then applied to the appropriate plots on May 30, 2019 (Borderview Farm) and May 31, 2019 (Bridgeview Farm). A soil assay to determine if EPNs were successfully applied was conducted 40d and 50d respectively post application. At the Borderview Farm location, randomly selected corn roots were dug out of each replicated block, washed and evaluated for feeding damage using the Iowa scale. Root ratings were conducted in a double blind format; the rating information was recorded.

In PA, a two-acre demonstration plot was established on the Schrack Farm, on June 14, 2019. A soil assay to determine if EPNs were successfully applied was conducted 100d post application; an assay was also conducted in an adjacent control plot to verify no EPNs were present. The site was not evaluated for corn root damage this year.

UPDATE 2022 - No on-site evaluation were conducted at the Schrack Farm throughout the project , site was strictly used to conduct the assay and population evaluations.

Two of the three NYS demonstration sites previously established were assayed to document persistence by EPNs. The Musgrave site had a spring and fall soil assessment in each event, EPNs were found to still be persisting within the treated areas. The Stokoe Farm site was assayed in the early summer, post planting to determine if EPNs were still persisting within the treated areas; EPNs were also persisting at this site. Corn root damage assessment was conducted at the Musgrave Research location only in 2019; within the Steinernema sp. replicated blocks. For each block as well as the untreated designated blocks, corn roots were dug out, washed and evaluated for feeding damage using the Iowa scale. Root ratings were conducted in a double blind format; the rating information was recorded.

2020-Year 2

This year all three research groups were limited on research outside their respective universities due to mandates and restrictions brought on by the COVID-19 pandemic. The hope for all three groups is that for the 2021 growing season will be a return to more standard objectives to attain all milestones.

UPDATE JUNE 2022  - Extended research of farms was restricted due to the onset of the global pandemic. Mandated restrictions for all three universities due to COVID-19 prevented researchers to conduct a more standard evaluation to achieve the objectives in the milestones.

In VT, the two demonstration sites (Borderview Farm and Bridgeview Farm) were assayed in the spring (290d and 330d respectively) prior to planting and then once again post-harvest (484d and 523d) to verify nematode populations. At the Borderview Farm location, randomly selected corn roots were dug out of each replicated block, washed and evaluated for feeding damage using the Iowa scale. Root ratings were conducted in a double blind format; the rating information was recorded.

In PA, all research was limited to the demonstration plot located at the Larson Ag Research Farm. The 16-replicated blocks were assayed in the spring (350d) prior to planting and then post-harvest (526d) to verify nematode populations within the treated plots (Bt and non-Bt variety). The Tooker Lab also evaluated selected corn roots within the blocks for CRW damage using the Iowa scale. Root ratings were conducted in a double blind format; the rating information was recorded. A drought in the summer resulted in more damage within the treated plots than previously reported as nematodes had difficulty moving throughout the soil to locate CRW larvae.

In NYS, the demonstration site established at the Musgrave Research Farm was assayed to document persistence by EPNs. The Musgrave site had a spring soil assessment in each event; within the continuous corn (2,174d) and combination corn/soy blocks (2,189d). EPNs were found to still be persisting within all the treated areas. Another soil assessment was conducted 2, 189d within the continuous corn blocks to verify nematode populations. Samples were removed from the soil surrounding the area were roots had been removed; inside the area covered by screen tents and outside the screen tents. Corn root damage assessment was conducted within the Steinernema sp. replicated blocks only in 2020. For each block as well as the untreated designated blocks, corn roots were dug out, washed and evaluated for feeding damage using the Iowa scale. Root ratings were conducted in a double blind format; the rating information was recorded.

2021-Year 3

All three research groups were limited to some degree on research outside their respective universities due to mandates and restrictions brought on by the COVID-19 pandemic.

Milestone #5 (click to expand/collapse)
What beneficiaries do and learn:

5) In NY, where the concept has been proven, 20 farms per year in years 1& 2 will be recruited to treat a single field with untreated check strips (total farms = 40). (Dec 2019, Dec 2020).

Proposed number of farmer beneficiaries who will participate:

20

Proposed number of agriculture service provider beneficiaries who will participate:

1

Actual number of farmer beneficiaries who participated:

19

Actual number of agriculture service provider beneficiaries who participated:

2

Proposed Completion Date:

December 31, 2021

Status:

Completed

Date Completed:

September 30, 2021

Accomplishments:

2019-Year 1

During the first year of the study, the Shields' Lab was able to recruit 10 farms to treat portions of selected fields with bio-control nematodes; each field site had areas remaining untreated. Two of these demonstration sites the EPNs were applied using commercially available pesticide sprayers, the remaining fields the EPNs were applied using liquid manure. At each site, farmers adhered to the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)) in establishing their demonstration plots. Each demonstration site was between 1 and 3 acres in treated areas.

2020-Year 2

Recruitment was limited this year due to the restrictions of COVID-19 and the financial impact it has had on agriculture in NYS. The Shields’ Lab was able, with the assistance of extension agents and consultants to recruit 4 additional farms to treat portions of selected fields with biocontrol nematodes; each field site had areas remaining untreated. All four demonstration sites had EPNs applied using farm owned spray rigs with assistance from the local consultants. At each site, farmers adhered to the multi-species approach, two native NY strains of bio-control entomopathogenic nematodes (EPNs), (Steinernema carpocapsae (Sc) and Steinernema feltiae (Sf)) in establishing their demonstration plots.

2021-Year 3

Recruitment was limited this year due to the restrictions of COVID-19 and the financial impact it has had on agriculture in NYS. The Shields’ Lab was able, with the assistance of extension agents and consultants to recruit 5 additional farms to treat portions of selected fields with biocontrol nematodes; each field site had areas remaining untreated. Three of the five demonstration sites had EPNs applied using farm owned spray rigs with assistance from the local consultants. The two additional sites, Table Rock and Doubledale Farm, biocontrol nematodes were applied using a commercial applicator familiar with the technology and application of biocontrol nematodes. For 2021, farmers applied only one of the native NY strains of biocontrol entomopathogenic nematodes (EPNs), Steinernema feltiae (Sf) in establishing their demonstration plots.

Milestone #6 (click to expand/collapse)
What beneficiaries do and learn:

6) In VT and PA, five farms will be recruited in each state to treat a single field prior to the final growing season of the grant (Yr 3). Interested growers will be recruited through various established Extension networks or educational events. (Dec 2021).

Proposed number of farmer beneficiaries who will participate:

5

Actual number of farmer beneficiaries who participated:

1

Proposed Completion Date:

December 31, 2021

Status:

Completed

Date Completed:

August 31, 2021

Accomplishments:

2019-Year 1

Recruiting efforts will increase in 2020.

UPDATE JUNE 2022  - Recruiting efforts were restricted due to the onset of the global pandemic. Mandated restrictions for all three universities due to COVID-19 prevented researchers to do in-person recruitment and limited travel.

2020-Year 2

In both states researchers were unable to recruit due to the limitations of COVID-19 restrictions mandated by their respective universities.

2021-Year 3

With the recruitment of N. Island Dairy during the 2021 growing season, the total number of farms that adopted the use of persistent biocontrol nematodes was 4. The other 3 farms were recruited and applied biocontrol nematodes in 2019. Unfortunately, much of the recruitment intended for this project was limited due to the COVID-19 pandemic.

Sites in Vermont and New York will continue to be monitored post-project for losses due to corn rootworm and yield restoration as a direct impact from using EPNs. The researcher site located on the Larson Ag Research Farm will also be monitored but may not remain in continuous corn post project. All demonstration sites will serve a residue population for EPNs for any future research or work using EPNs.

Milestone #7 (click to expand/collapse)
What beneficiaries do and learn:

7) Yearly outreach to over 300 growers will include field days, twilight meetings, winter meeting talks, articles in newsletters/popular press and Extension publications. All written articles will be available online. Demonstrations will include on-farm rearing to the biocontrol nematodes and application with common pesticide sprayers. (Dec 2019, Dec 2020, Dec 2021).

Proposed number of farmer beneficiaries who will participate:

300

Proposed number of agriculture service provider beneficiaries who will participate:

3

Actual number of agriculture service provider beneficiaries who participated:

2

Proposed Completion Date:

December 31, 2021

Status:

Completed

Date Completed:

December 31, 2021

Accomplishments:

2019-Year 1

At the field days in NY, PA and VT, farmers were able to see how the on-farming concept works and were able to participate and ask questions on the procedures for EPN application.

The Shields' Lab made available through the website, http://www.alfalfasnoutbeetle.org/ a updated protocol for biological control using persistent EPNs.  The document can also be found Cornell - Shields SOP for Persistent EPNs.

Yearly outreach in 2019 was 400 -500 growers and agribusiness individuals; most attended field days held in each participating project state.

 The document can also be found Cornell - Shields SOP for Persistent EPNs

2020-Year 2

No field days, in-person meetings, or demonstrations were conducted during the 2020 research year. While unable to be physical present this year, the Shields’s Lab is confident that the application and assay protocols developed in the lab have proven to be useful tool in disseminating the necessary information to interested growers to have successful nematode applications.

While limited on in-person meetings, the Shields’ Lab continued to put out articles on the benefits of adapting to using bio-control nematodes to control corn rootworm. These publications have reached an unknown number of farmers in 2020, some of which have reached out to express interest beyond the states involved in this current project. The following three articles were referenced in various newsletters/popular press and extension publications during the past year beyond just NYS.

2021-Year 3

At the field days in VT and NY, growers and agribusiness were able to see how the on-farming concept works and were able to participate and ask questions on the procedures for EPN application.

Throughout much of 2021, an effort was made to broadcast the opportunity to test the potential of this biological control technology against CRW in NY. Unlike previous years, the pandemic limited our abilities to utilize available extension programs including presentations at winter meetings. Whenever possible, research results to that point, were shared through online conversations (ZOOM), press releases, and news articles. While limited in-person meetings, the Shields’ Lab published an article for Cornell Field Crops, What’s Cropping Up? Blog. The article appeared on October 8, 2021, and can be found at the following link:

What's Cropping Up? Blog – Articles from the bi-monthly Cornell Field Crops newsletter

Elson Shields was a guest speaker at the Northeast field crop dealer meeting, on December 1, 2021. Elson presented virtually using ZOOM for certified crop advisors and his discussion focused on the current project, using biocontrol nematodes as a management tool.

Additionally, the Shields’ Lab made available to all a Standard Operating Procedure publication outlining effective biocontrol nematode management protocols.

Yearly outreach in 2021 was 400 -500 growers and agribusiness individuals; individuals participated via field days held in each participating project state, online with Zoominars, or in-person dealer meetings.

 

Milestone #8 (click to expand/collapse)
What beneficiaries do and learn:

8) 75 farmers interested in “trying” the biological control treatment will receive a project fact sheet and one-on-one technical assistance with implementation of practices. (Dec 2022).

Proposed number of farmer beneficiaries who will participate:

75

Actual number of agriculture service provider beneficiaries who participated:

2

Proposed Completion Date:

December 31, 2021

Status:

Completed

Date Completed:

December 31, 2021

Accomplishments:

2019-Year 1

Have yet to begin the creation of project fact sheet, nor has the project coordinators worked one-on-one with assistance. Farms participating in 2019 received one-on-one technical assistance with implementation of practices for demonstration plots.

UPDATE JUNE 2022  - The Shields’ Lab created a 4-page fact sheet on the application of biocontrol nematodes for control of corn rootworm beginning in the winter of 2020. Once it was completed, the Shields' Lab made available to all interested growers and/or agribusiness individuals beginning in 2020.

CRW - EPN corn spray guide 2020

2020-Year 2

In Western NY, three farms expressed interest in trying bio-control nematodes for the first time. Each farm received CRW-EPN corn spray guide prior to applying biocontrol nematodes.

Due to limitations on travel and in-person assistance, the Shields' Lab relied on using extension agents and consultants as a means to provide one-on-one technical assistance with implementation of practices related to application of the nematodes. The agents/consultants, as well as the farms were provided facts sheets previously used prior to the beginning of this project to provide a background on application protocols. 

The Shields’ Lab began creating  a Standard Operating Procedure (SOP) publication for use by growers and agribusiness in early 2021. This SOP will be the best resource for interested growers and/or agribusiness individuals interested in assisting their growers in the application of persistent biocontrol nematodes.

All three applications in Western NY proved to be successful. One of the Western, NY farms has continued to acquire EPNs in 2021 and 2022.

2021-Year 3

The Shields’ Lab made available to all expressing interest in this project  along with the CRW-EPN fact sheet a Standard Operating Procedure publication outlining effective biocontrol nematode management protocols. This guideline has proven to be the best resource for interested growers and/or agribusiness individuals interested in assisting their growers in the application of persistent biocontrol nematodes. Also shared with interested growers or agribusiness were the links to taped Zoominars in which Elson Shields discussed the current project, biological control of corn rootworm in conventional and organic corn production.

UPDATE JUNE 2022  - The Shields’ Lab made available to all the CRW-EPN fact sheet and the Standard Operating Procedure publication outlining effective biocontrol nematode management protocols for the 2021 growing season. 

Cornell - Shields SOP for Persistent EPNs

Milestone Activities and Participation Summary

Educational activities:

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

Participation Summary:

14 Farmers participated
9 Number of agricultural educator or service providers reached through education and outreach activities

Learning Outcomes

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

In NYS – the knowledge has been passed along over the past five years on the potential benefits of using EPNs for pest control in organic and commercial plantings. Farmers in Northern NY had been slowly adopting the use of EPNs for control of alfalfa snout beetle while the new research focused on the benefits associated with the persisting nature of the native species to remain in fields as sufficient population levels after a rotation into corn to combat corn rootworm.

The opportunity by the commercial applicators in Northern NY to add another service for their clients was initially met with some skepticism. However, once it was demonstrated that the process to apply was easy, and that farmer’s willing to pay for the applications, the market increased. One service provider took it the next step and began rearing and providing EPNs as part of the application process, gaining new clients as well as providing the benefits of EPNs for pest control which they strongly promote.

The development and advancement in how the nematodes can be stored long-term, using aeration has prolonged the time that biocontrol nematodes can be stored while remaining viable. This innovation also allows a different delivery method, nematodes suspended in a liquid state. Delivery in this manner provides the commercial applicator a more feasible, flexible, and farm friendly way to provide the service of applying biocontrol nematodes to their clients.

Performance Target Outcomes

Target #1

Target: number of farmers:

50

Target: change/adoption:

Fifty farms in NY, VT, and PA will implement biological control on 500 acres of corn to manage corn rootworm

Target: amount of production affected:

500 acres

Target: quantified benefit(s):

As a result farmers will reduce production costs by $50 per acre by reducing corn rootworm management costs (using non-Bt-CRW corn seed or eliminate soil insecticide). For the conventional corn producer, measurable benefits can be found with increased profits and decreased input costs resulting from lower costs in controlling CRW either by planting conventional corn or not using soil insecticides. For the Organic producer, increased yields and increased profits can be measured.

Actual: number of farmers:

22

Actual: change/adoption:

Farms in this study, chose to adopt this new technology; adopting bio-control entomopathogenic nematodes to control corn rootworm and other field pests. The end result is a long-term impact on their production of commercial or organic products after a single application; increased yields and lower costs associated with insect control.

Actual: amount of production affected:

While the target number of farms who adopted this new technology was not met, those that did adopt applied persistent biocontrol nematodes to over 1,200 acres

Actual: quantified benefit(s):

Farms adopting this technology can expect an increase in profits and decreased input costs for the conventional corn producer. For the Organic producer, increased yields and profits are expected as measurable benefits.

While difficult to verify in actual dollars for each farm, the two decade's work in Northern New York where a single application of EPNs was conducted, farms have reported to researchers as well as extension agents the results are lower costs in controlling CRW. This management practice of using persistent biocontrol nematodes benefits farms as they can either plant conventional corn or not use soil insecticides. For the Organic producer, increased yields and profits are expected as measurable benefits.

Total number of farmers who made a change or adopted a practice as a result of participating in this project was twenty-two.

Performance Target Outcome Narrative:

While the initial target of the number of farmers willing to adopt persistent biocontrol technology as a new management practice for corn rootworm fell short of fifty (50), twenty-two (22) farms thought the technology was worth investing in and adopted the use of EPNs as an additional management tool against corn rootworm. The growth of adopters was hindered throughout the project due to the global pandemic, which made one-on-one interaction nearly impossible due to restrictions and mandates brought by each participating university.

In Year 1 (2019), thirteen farms across Pennsylvania, New York, and Vermont applied persistent biocontrol nematodes to corn fields. Due to the pandemic, growth was limited to three new additional farms in Year 2 (2020) and six new farms in Year 3 (2021). Research over twenty years in New York has shown that immediate results from applying persistent biocontrol nematodes is rare. Nematodes need time to move throughout the field; applied bio-control nematodes to become established in the soil profile and redistribute themselves from the high concentration application strip/streams into the area between the application streams. The result of this is typically, impact from bio-control nematodes is not evident until the second growing season. In addition, native persistent bio-control nematode strains have phased infectivity where all applied nematodes are not immediately infective. The immediately infective IJs search out hosts and recycle whereas the dormant IJs require the passage of time to become infective before they search out hosts. In year 2, inoculated fields can be planted to non-GMO-CRW corn varieties without soil insecticide and the growers should not observe any losses from CRW or CRW related yield losses. The benefit will be reduced input costs and maintenance of previous yield.

Verification is difficult to measure in dollars and often is expressed as yield restoration by participating farmers. One measurable benefit expressed to the Shields’ Lab over the past 20 years in general terms is that farmers using this management practice can expect an increase in profits and decreased input costs for the conventional corn producer. For the Organic producer, increased yields and profits are expected as measurable benefits.

While the project failed to reach the target number of farmers, the overall acreage treated by those farmers adopting this technology more than doubled. The twenty-two farms applied the persistent biocontrol nematodes to 1,266 acres of continuous corn. Selected fields were bio-assayed for the presence of bio-control nematodes to verify first establishment, then persistence after overwintering before the cropping season begins. Successful establishment and yield impact, cost reduction, as well as the benefit of a one-time cost for application per site, has encouraged several farms to take the next step with adoption by applying EPNs to other continuous corn fields on their farm. One final measurable benefit is the concept of adoption by association; neighbors of farms who have seen their neighbors embrace this technology are more willing to try it themselves. This has been recorded multiple times over the past twenty years in New York.

22 Farmers changed or adopted a practice

Additional Project Outcomes

2 Grants applied for that built upon this project
2 Grants received that built upon this project
$111,333.00 Dollar amount of grants received that built upon this project
15 New working collaborations
Success stories:

Corn is the nation’s largest crop and corn rootworm (CRW) is the nation’s most expensive pest with farmer’s CRW control expenditures exceeding $2 B annually. In addition, CRW has developed strategies/resistance to defeat any management technology used widely including Bt-RW corn. Management technologies fail because they are primarily deployed as a single management strategy, placing extreme selection pressure on CRW to defeat the technology to survive.

Persistent biocontrol nematode technology developed in Northern New York as a management strategy against alfalfa snout beetle, has proven over the past decade to also be effective against corn rootworm in fields rotated out of alfalfa into corn as well as continuous corn fields. This project, from the beginning, was to demonstrate the effectiveness of this new technology as an additional management tool for farmers dealing with existing and increasing corn rootworm populations in New York, Pennsylvania, and Vermont.

The study demonstrated how effective and easily this technology could be adopted by farmers and agribusiness. In addition, this persistent biocontrol nematode technology is completely compatible with other management tools like Bt-RW and operates as a second independent mortality factor to reduce the insect resistance development to other management strategies. Biocontrol nematode efficacy against CRW and multi-year persistence has also been demonstrated in this completed joint research.

Assessment of Project Approach and Areas of Further Study:

The goal at the beginning of this project was to make available this new technology to farmers and agribusiness individuals within the three cooperating states involved in this joint research. The outset of the COVID-19 limited our approach to having more demonstration plots and in-person educational opportunities to increase outreach. Focus turned to what was available, Zoominars. Zoominars allowed a greater audience to be educated on the benefits of adopting persistent biocontrol nematodes to control corn rootworm.

The creation of the Shields’ Lab SOP for biological control with persistent entomopathogenic nematodes and the corn rootworm spray guide both, allowed cooperators and service providers a detailed description on how to rear, apply, conduct soil bioassays, as well as instructions on how to maintain the persistent characteristics for preservation of each species.

Opportunities for farmers and agribusiness to apply using persistent biocontrol nematodes in liquid manure was disappointing. Overall, researchers acknowledge the ease of adoption while also realizing that one area that continues to hold back adoption or increase current scale of applications is the application method itself in a field setting. The research and results conducted in this project have been enlightening and has re-focused the Shields’ Lab for future research.

Future research will focus on researching new procedures to allow delivery of nematodes in a liquid state for quicker transfer into application sprayers. Additionally, formulation modifications on concentrations and shelf life to increase long-term storage of the nematodes. An increase of shelf life and a more user-friendly formulation, removes a lot of the complexities involved with timely EPN production and field application, opening the door to a wider adoption across agriculture.

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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.