Biological Control of Corn Rootworm in Conventional and Organic Corn Production

Progress 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

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

Click linked name(s) to expand/collapse or show everyone's info
  • 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 field cages. Single 10X10 screen cages were placed within each demo-block prior to the anticipated adult CRW emergence around mid-July. All screen cages (total of 16) were set up by July 6th, 2019. Observations for CRW adult emergence began on July 8, 2019. Cages 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 using field cages from both the bio-control nematode treated and untreated plots. Two 10X10 screen cages were placed within each demo plot prior to the anticipated adult CRW emergence around mid-July (Northeast and Southwest corners). All screen cages (total of 16) were set up by July 10th, 2020. Observations for CRW adult emergence began on July 13th, 2020. Cages 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.

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.

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 field cages. Single 10X10 screen cages 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 cages (total of 12) were set up by July 10th. Observations for CRW adult emergence began on July 15, 2019. Cages 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 using field cages from both the bio-control nematode treated and untreated plots. Single 10X10 screen cages 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 cages (total of 12) were set up by July 17th, 2020. Observations for CRW adult emergence began on July 21st, 2020. Cages 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.

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.

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. Adult collection cages (screen tents) were erected in the corn plots located at Musgrave Research Farm, began setting up on July 9th.  Single 10x10 screen cages were placed over the Steinernema sp. variety x treatment x replication prior to the anticipated adult CRW emergence around mid-July. All screen cages (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.

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 cages added to collect any surviving adult CRWs. All screen cages (total of 12) were set up by July 12th.

Observations for CRW adult emergence began on July 15, 2019. Cages 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 Year 2, a spring assay to verify bio-control nematode populations will be attempted in Year 3 if current mandates limiting travel and research are lifted.

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. Adult collection cages (screen tents) were erected in the corn plots located at Musgrave Research Farm, began setting up on July 6th, 2020. Single 10x10 screen cages were placed over the Steinernema sp. variety x treatment x replication prior to the anticipated adult CRW emergence around mid-July. All screen cages (total of 12) were set up by July 8th, 2020. Researchers determined that the evaluation on the Steinernema feltiae and Hetrorhabditis bacteriophora treated areas would not occur in 2020.

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 cages added to collect any surviving adult CRWs. All screen cages (total of 9) were set up by July 6th, 2020.

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.

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 and persisting. The fluctuations in assay results will need further analysis in comparison to future soil assays in Year 3 and the subsequent evaluations on CRW presence and damage at the demonstration site.

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

2021

 

 

 

 

             

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

 

 

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. The fluctuations in assay results will need further analysis in comparison to future soil assays in Year 3 at the Bridgeman View Farm.

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

2021

 

 

 

 

             

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

2021

 

 

 

 

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.

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.

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

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

Cry 34/35

.12

.05

.95

.14

SmartStack

.10

.01

.13

.04

Cry 3Bb1

.20

.07

.72

.08

 

 

 

 

 

 

Untreated variety

Untreated variety

 

Outside Tents

Inside Tents

 

Mean

SE

Mean

SE

Conventional Corn

.49

.13

2.13

.07

Cry 34/35

1.13

.2

1.87

.14

SmartStack

.10

0

.15

.02

Cry 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

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

Cry 34-35

4,274

1,425

379

3,746

937

285

Smart Stack

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

Cry 34/35

.17

.15

.29

.12

SmartStack

.07

.01

.10

.02

Cry 3Bb1

.10

.03

-

-

 

 

 

 

 

 

Untreated variety

Untreated variety

 

Outside Tents

Inside Tents

 

Mean

SE

Mean

SE

Conventional Corn

.64

.25

.68

.26

Cry 34/35

.83

.24

1.39

.08

SmartStack

.09

.01

.07

.02

Cry 3Bb1

.77

.23

-

-

 

 

 

 

 

 

Sf & Hb EPN Combo

 

 

 

No Tents

 

 

 

Mean

SE

 

 

Conventional Corn

.84

.25

 

 

Cry 34/35

1.14

.07

 

 

SmartStack

.10

.01

 

 

Cry 3Bb1

.16

.04

 

 

 

 

 

 

 

Participation Summary
24 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.

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:
6
Proposed Completion Date:
December 31, 2019
Status:
Completed
Date Completed:
December 31, 2019
Accomplishments:

2019-Year 1

Six 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.

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

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.

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:
3
Actual number of farmer beneficiaries who participated:
6
Proposed Completion Date:
December 31, 2020
Status:
In Progress
Accomplishments:

2019-Year 1

Six 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.

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.

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:
3
Actual number of farmer beneficiaries who participated:
5
Proposed Completion Date:
December 31, 2021
Status:
In Progress
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.

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.

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.

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
Actual number of farmer beneficiaries who participated:
17
Proposed Completion Date:
December 31, 2020
Status:
In Progress
Accomplishments:

2019-Year 1

During the first year of the study, the Shields' Lab was able to recruit 13 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.

 

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
Proposed Completion Date:
December 31, 2021
Status:
In Progress
Accomplishments:

2019-Year 1

Recruiting efforts will increase in 2020.

2020-Year 2

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

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
Actual number of farmer beneficiaries who participated:
327
Proposed Completion Date:
December 31, 2021
Status:
In Progress
Accomplishments:

2019-Year 1

At the field days in VT and NY, 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.

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, 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.

 

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 farmer beneficiaries who participated:
3
Actual number of agriculture service provider beneficiaries who participated:
2
Proposed Completion Date:
December 31, 2022
Status:
In Progress
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.

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. 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. These fact sheets will be updated in the final year of this project.

Milestone Activities and Participation Summary

Educational activities:

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

Participation Summary:

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

Learning Outcomes

20 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 meant 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.

Performance Target Outcomes

Target #1

Target: number of farmers:
50
Target: change/adoption:

50

Target: amount of production affected:

500 acres

Target: quantified benefit(s):

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:
17
Actual: change/adoption:

Adopting bio-control entomopathogenic nematodes to control corn rootworm and other field pests impacting their production of commercial or organic products

Actual: amount of production affected:

N/A

Actual: quantified benefit(s):

Increase in profits and decreased input costs for the conventional corn producer because of lower costs in controlling CRW either by planting conventional corn or not using 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.

Performance Target Outcome Narrative:

Seventeen farms have applied bio-control nematodes to corn fields. Typically, impact from bio-control nematodes are not evident until the second growing season because time is required for the 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.  In addition, these 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, each of these fields will be bio-assayed for the presence of bio-control nematodes to verify establishment and overwintering before the cropping season begins.  Farmers should see the impact of these inoculated bio-control nematodes in the second growing season based on the NY research over multiple growing seasons.  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.

20 Farmers changed or adopted a practice

Additional Project Outcomes

13 New working collaborations
Success stories:

2019-Year 1 - It is too early in the project for farmers to have experienced success stories.  Full impact of biocontrol nematodes will be observed in year 2 and 3 of the project.

2020-Year 2 – Despite the COVID-19 pandemic limiting research and impacting farms financially, four farms who had expressed interest in attaining bio-control nematodes for application in the management of corn rootworm were successful in doing so this past year. Any potential observations on the impact biocontrol nematodes had for those farmers adding demonstration plots from Year 1 were limited or not achieved. Our goal is to observe, record and report any impact biocontrol nematodes had on the participating farms in the final year of this project.

Assessment of Project Approach and Areas of Further Study:

The creation of the Shields’ Lab standard operational procedures for biological control with persistent entomopathogenic nematodes has allowed cooperators and service providers a detailed description on how to rear, apply, conduct soil bio-assays, as well as instructions on how to maintain the persistent characteristics for preservation of each species.

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 on application with liquid manure has shown to be a quick means to apply nematodes without too much labor. Additionally, the Shields’ Lab is currently researching new procedures to allow delivery of nematodes in a liquid state for quicker transfer into application sprayers.

 

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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.