2020 IOWA EVALUATION OF INSECTICIDES AND PLANT

IOWA STATE UNIVERSITY OF SCIENCE AND TECHNOLOGY

2020 IOWA EVALUATION OF INSECTICIDES AND

PLANT-INCORPORATED PROTECTANTS

CORN PESTS RESEARCH PROJECT

DEPARTMENT OF ENTOMOLOGY AMES, IOWA 50011-3140

Stephen Dinsmore, CHAIR

INSECTS INVESTIGATED

Corn Rootworm

Diabrotica virgifera virgifera and Diabrotica barberi &

Black Cutworm Agrotis ipsilon

Report Authors March 2, 2021 Aaron Gassmann File number: 307-20 Ben Brenizer

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2020 IOWA EVALUATION OF INSECTICIDES AND PLANT INCORPORATED PROTECTANTS

TABLE OF CONTENTS Page 1. Research Personnel .......................................... 1 2. Introduction and Objective ............................... 2 3. Testing Procedures and Evaluations ........... 2-5 4. Results and Discussion ................................ 5-6 5. Studies Conducted ........................................... 7 6. Corn Rootworm Evaluation Tables Ames (Johnson Farm) Insecticide on non-RW Bt corn Root Injury/Percent Consistency ............. 8 Stand Count ............................................ 9 Yield ...................................................... 10 Insecticide on non-RW Bt corn Root Injury/Product Consistency ........... 11 Stand Count .......................................... 12 Yield ...................................................... 13 Insecticide on RW Bt corn Root injury/Product Consistency ........... 14 Stand Count ……...……...………...........15 Yield.……………………….…….….........16 Boone (Bruner Farm) Insecticide on non-RW Bt corn Root Injury/Product Consistency ........... 16 Stand Count .......................................... 17 Yield ...................................................... 17

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Insecticide on non-RW Bt corn Root Injury/Product Consistency ........... 18 Stand Count .......................................... 18 Yield ...................................................... 19 Insecticide on non-RW Bt corn Root Injury/Product Consistency ........... 20 Stand Count .......................................... 21 Yield ...................................................... 22 Black Cutworm Study Stand Count .......................................... 23 Yield ...................................................... 23 7. Appendix I - Agronomic Information ....... 24-25 8. Appendix II – Weather Data ...................... 26-29 9. Appendix III - Materials Tested ................. 30-31 10. Appendix IV - Research Pictures .................. 32

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2020 IOWA EVALUATION OF INSECTICIDES AND PLANT INCORPORATED PROTECTANTS

CORN PESTS RESEARCH PROJECT

DEPARTMENT OF ENTOMOLOGY

AMES, IOWA 50011-3140

Project Leader: Aaron Gassmann

Research Associate II: Ben Brenizer

Assistant Scientist III: Ram Shrestha Graduate Research Assistants: Coy St. Clair Abigail Kropf John McCulloch Eliott Smith Technical Assistants: Mattea Contreras Jiage (Leslie) Du Lydia Holmes Kc Kenney Ryan Meehan Rylee Patterson University Research Farm Superintendents: Kent Berns Mike Fiscus Dallas Maxwell Kenneth Pecinovsky Myron Rees

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INTRODUCTION In Iowa, the species of corn rootworm (CRW) that are of economic importance include western corn rootworm Diabrotica virgifera virgifera LeConte and northern corn rootworm D. barberi Smith and Lawrence, and these two species are the most damaging pests of corn, Zea mays, in the United States Corn Belt. Eggs are laid in the soil during the summer and hatch the following spring. Larval feeding on corn roots in June may diminish yield by reducing plant growth and drought tolerance, and by imposing harvest losses due to plant lodging. Adult emergence from the soil is underway by early July, with most adult emergence completed by mid-August. Additional crop losses may be caused by adult beetles feeding on corn silk and soft doughy kernels. In Iowa, crop rotation, where it fits cropping practices, remains the preferred method of management. However, it is also economically feasible to protect corn roots with soil-applied insecticides and plant incorporated protectants, which are transgenic corn hybrids that produce insecticidal toxins derived from Bacillus thuringiensis (Bt). In additional to corn rootworm, several above-ground lepidopteran pests feed on corn in Iowa. These include the European corn borer Ostrinia nubilalis, black cutworm Agrotis ipsilon, fall armyworm Spodoptera frugiperda, and corn earworm Helicoverpa zea. Over the last two decades, Bt corn varieties have been made commercially available to protect corn from these pests.

OBJECTIVE The goal of this research program is to serve the agricultural community of Iowa by monitoring and evaluating the performance of registered and pre-

commercial insecticides and transgenic corn hybrids. To achieve this goal, we maintain a viable, proactive, progressive and scientifically sound product evaluation program.

TESTING PROCEDURES AND

EVALUATIONS Field Sites: Research plots were established at two Iowa State University Research and Demonstration Farms in 2020: 1) Johnson Farm (Story County) and 2) Bruner Farm (Boone County). At these two locations, two sections of the study site are rotated annually as either research plots or late-planted trap crop. The seed planted for the trap crop is a mixed maturity blend with a greater proportion of late-maturing varieties. This trap crop constitutes a favorable environment for adult female CRW late in the season when other fields are maturing, and can result in a high abundance of CRW larvae the following season. Table 1 lists the CRW studies conducted at each location, and provides information on a study conducted with black cutworm.

METHODS

Field plot design: For all locations, the experimental design was a randomized complete block with four replications. Corn rootworm field plots were 4 rows wide and 35 feet in length. Plots were cut back to 30 feet in length after planting to facilitate root digging. Planting: Unless state otherwise, seeds were pre-bagged in the laboratory and then planted with a four-row John Deere Max EmergeTM 7100 Integral Rigid Frame Planter that had 30-inch row spacing. Seeds were planted at a depth of 2 inches with a spacing of 6 inches between seeds (35,600 seeds per acre).

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The standard planter fiberglass seed hoppers with attached finger-pickup mechanism were replaced with modified units. On these modified units, the metal plate that covered the fingers was replaced with a 7/8 inch clear Plexiglas plate. Inserted through the Plexiglas was a small stainless-steel cylinder. The cylinder was positioned to deliver seed to the pickup fingers. At the beginning of each replication, pre-bagged seeds were poured into the steel cylinder. At the beginning of each replication, a hydraulic motor (attached to the planter’s drive shaft) was activated to deliver seed immediately into the ground. At the end of each replication, this same hydraulic motor was activated to expel any unplanted seed, and the finger pickup mechanism was visually inspected through the clear Plexiglas plate to ensure that no seed was present. Planting of studies that only evaluated a single hybrid was accomplished by adding bulk seed hoppers to the planter. Plant-incorporated protectants: Plant-incorporated protectants were evaluated in corn hybrids producing insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt), and these are described in Appendix III. Seed treatments: All the DeKalb hybrids were treated with Acceleron 250. These seed treatments target secondary pests, such as wireworm and seed corn maggot but may have some, limited efficacy against CRW larvae at levels higher than 250 mg active ingredient per kernel. MBI-206 BM3SE1, MBI-306 SC1, MBI-3P1b, and Abamectin + Thiamethoxam was applied to seeds in the Marrone Bio Innovations Study (Tables 2-4). Poncho 600 was applied to seeds in the Valent Study (Tables 5-7). NIPSIT was applied

to seeds in the Valent black cutworm Study (Tables 20-21). Granular soil-applied insecticides: The granular insecticides Aztec 2.1G and Force 3.0G were applied with modified Noble® metering units mounted on the planter. The Noble units were calibrated in the laboratory to accurately deliver material at a tractor speed of 4 mph. Aztec 2.1G and Force 3.0G insecticides were applied with in-furrow placement. Liquid soil-applied insecticides: Insecticides were applied in-furrow at planting with a compressed-air system built directly into the planter by Almaco manufacturing (Nevada, IA). All liquid products were applied as ounces per 1000 row feet. All liquid insecticides were applied with a Teejet XR80015EVS spray nozzles at 21 psi to deliver 5 GPA of finished spray at a tractor speed of 4 mph. Before the field plot season, new spray nozzles were installed and calibrated with water to ensure proper application of product. For these liquid applications each row was checked for correct spray pattern prior to plot application and monitored during application to ensure that insecticides were applied correctly. Final incorporation was accomplished with drag chains. SmartBoxTM application of soil-applied insecticides: Aztec-HC 9.34G insecticide was applied with modified SmartBoxTM metering units mounted on the planter. The commercial SmartBoxTM units were removed from their large-base containers and sandwiched between a flat metal plate on the bottom and a custom-made, threaded plastic cap on the top. The bottom plate was fabricated so that it could slide in and out of the

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same planter mounting brackets used for the Noble units. An inverted 1 L Nalgene bottle attached to the top provided a secure and sealed container for insecticide for the SmartBoxTM units. Clear plastic tubes directed the granular insecticides to both the in-furrow and T-band placement. A controller mounted in the tractor cab was used to operate all the SmartBoxTM metering units. These units were managed using the AMVAC SmartBox System Manager. All treatments were applied at 4 mph using the “fixed speed mode” on the SmartBoxTM controllers. These SmartBoxTM metering units were calibrated before going to the field to deliver ounces of product per 1000 row feet. General methodology: During planting, each row was constantly monitored to ensure that insecticides were applied correctly. Final incorporation was accomplished with drag chains mounted behind the closing wheels.

Evaluations Stand counts: These were measured by laying a two-inch PVC pipe cut to the length of 17’5” long (1/1000 of an acre for 30-inch row spacing) between the two corn rows and counting the number of plants in both rows. Late season stand counts were measured following the same procedure as early season stand counts. Measurements for both dates were averaged to provide a single value for stand counts. Due to heavy rainfall and standing water the study found in tables 17-19 had reduced stand counts in the first block for the following treatments: Bifender(0.34 rate), MBI-306 SE1(0.60 rate), MBI-306 SE1(0.60 rate) + Bifender(0.34 rate),

MBI-306 SE1(0.60 rate) + Bifender(0.84 rate), VCP-031(0.91 rate), and Force EVO. Root injury: After the majority of corn rootworm larvae had finished feeding, roots were dug to assess feeding injury. This took place from July 20 to July 29, 2020. Prior to leaving the field, excess soil was removed from roots and all roots were labeled with study name and plot number using a fine-point permanent marker. Roots were cleaned at the ISU Johnson Farm’s root washing station. Roots were first soaked in water for 2 to 8 hours and then washed with a hose to remove any remaining soil. Roots were evaluated for rootworm feeding injury following the Iowa State University 0 to 3 node-injury scale: Node-Injury Scale (0-3): 0.00 - No feeding injury (lowest rating

that can be given). 1.0 - One node (circle of roots), or the

equivalent of an entire node, pruned to within 1.5 inches of the stalk or soil line.

2.00 - Two nodes pruned. 3.00 - Three or more nodes pruned.

(Highest rating that can be given) Injury between complete nodes pruned is noted as the percentage of the node missing (e.g., 1.50 = one and a half nodes pruned and 0.25 = one quarter of one node pruned). The linear node-injury scale allows injury to be expressed intuitively and has proved useful in evaluating minor injury. For an interactive guide to the node-injury scale, see the website for the Department of Entomology at Iowa State University. http://www.ent.iastate.edu/dept/faculty/gassmann/rootworm

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Product consistency: Percent product consistency was calculated as the percentage of times a treatment limited feeding injury to 0.25 node or less (greater injury can result in economic yield loss, especially when plants are moisture stressed). Black Cutworm Study: For the black cutworm study, field plots were 2 rows wide and 25 feet in length. Plots were cut back to 20 feet and metal barriers were placed around one row per plot to contain black cutworm larvae. Plants were infested on May, 27, 2020 with 2 larvae placed on each plant. Larvae used for infesting plants ranged from 3rd to 5th instar. Initial stand counts were collected on May 27, 2020 prior to infestation of the plants. Stand counts included every plant located within the barriers. The second stand counts were collected on June 3, 2020 and the third on June 11, 2020. The second and third evaluation recorded the number of uncut plants within the barrier. The difference between the initial stand counts and the other stand counts were used to determine the number of cut plants. Yields: Studies that were taken to yield were machine harvested with a modified John Deere 9450 plot combine owned by Iowa State University. Weight (pounds) and percent moisture were recorded with a high capacity grain gauge, (HarvestMaster brand), which used Mirus harvest software. These measurements were converted to bushels per acre of No. 2 shelled corn (56 lbs. per bushel) at 15.5% moisture in Microsoft Excel.

Due to the reduced stand counts in the study found in tables 17-19 yield wasn’t collecting in the first block for the following treatments: Bifender(0.34 rate), MBI-306 SE1(0.60 rate), MBI-306 SE1(0.60 rate) + Bifender(0.34 rate), MBI-306 SE1(0.60 rate) + Bifender(0.84 rate), VCP-031(0.91 rate), and Force EVO.

Data analysis Data were analyzed with analysis of variance (ANOVA) procedures using SAS Enterprise Guide 7.1. When a significant treatment effect was present pairwise comparisons made among means with an experiment wise error rate of P < 0.05.

Results and Discussion

In general, rootworm feeding pressure at the Johnson Farm was moderate to heavy. A study evaluating various experimental seed treatments had several treatments where an average of over 2 nodes of root injury was observed for some treatments (Table 2). This study did not detect any differences between the untreated check and the various treatments for root injury (Table 2). This result is consistent with past research, which has found limited reductions in rootworm feeding injury from seed treatments. Another study at the Johnson Research Farm evaluated various insecticides on non-Bt corn (Table 5), including both soil-applied insecticides and seed treatments. In this study, the untreated check suffered more than 1.5 nodes of injury on average. While some products significantly reduced root injury, others did not differ from the untreated check.

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Rainfall in April and June were well below normal (Appendix II) and this may have reduced the efficacy of soil-applied insecticides. A third study, conducted at the Johnson Research Farm tested the effect of soil-applied insecticide on non-CRW-Bt corn and on corn that contained rootworm active Bt traits (Table 8). When applied on non-CRW-Bt corn, soil insecticide significantly reduced root injury. However, when applied to Bt corn, no significant reduction in root injury was observed. In general, rootworm pressure at the Bruner Research was low, with untreated checks suffering less than 0.5 nodes of injury. Additionally, heavy rain during late May led to standing water in some studies, which makes data on root injury difficult to interpret. A study looking at the application of insecticides to non-RW-Bt corn, found some reductions in root injury from the application of soil-applied insecticide (Table 14). However, no significant effects on yield were detected (Table 16). Black cutworm is an early season pest that feeds on corn seedlings, often severing (cutting) plants at the base. We conducted a study that evaluated seed treatments and insecticides applied at planting as a management tool for black cutworm. We found some evidence of a reduced number of cut plants in one of our treatments, but in general, the number of cut plants did not differ from the untreated check (Table 20).

ADDITIONAL INFORMATION Agronomic information and field history are listed in Appendix I. Weather data from the test site or the nearest Iowa

climatological station are listed in Appendix II. Information on materials tested is listed in Appendix III. Pictures of various research activities are in Appendix IV.

RESEARCH SUPPORT Support for this research was provided by the Iowa State University Agriculture and Home Economics Experiment Station and by the following companies: AMVAC, Dow, FMC, Marrone Bio Innovations, Monsanto, and Syngenta.

WAIVER OF ENDORSEMENT

This report deals with the relative ability of each treatment to protect corn from damage by insects. This information is not presented to endorse the use of any product and the name of Iowa State University should not appear in any advertising without prior written consent. Iowa State University, their respective officers, agents, or employees, have not made, and do not hereby make, any representation, warranty or covenant with respect to the use of these test results, nor will they be liable for any damages, losses, or claims, including those of an incidental or consequential nature, arising out of the use of these test results.

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1All of the corn rootworm studies were conducted following a corn rootworm trap crop, to ensure the presence of rootworm larvae in the study; The black cutworm study was conducted following soybeans to reduce the presence of non-target pests

Test Location Types of Studies Table

Numbers Entries/

Test Rows/ Plot

Experimental Unit Size Row Length (ft) #Reps

Corn Rootworm Story County Johnson Farm

1) Insecticides on non-RW Bt corn (study #1)

2-4 15 4 30 4


5-7 9

4 30 4

3) Insecticides on RW Bt corn 8-10 8 4 30 4

Boone County Bruner Farm


11-13 5 4 30 4


14-15 8 4 30 4

3) Insecticides on Bt corn (study #3)

16-19 11 4 30 4

Black Cutworm Story County Johnson Farm

1) Insecticides on Bt corn 20-21 7 2 20 4

Table 1. Iowa evaluation of insecticides and plant-incorporated protectants.

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1 Planted April 29, 2020 evaluated July 23, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Non-RW Bt = Seed provided by MBI 3 All Insecticides listed as fluid ounces per 100 lbs. of seed

4 Seed treatments were applied to seed coat before planting 5 Means based on 20 observations (5 roots/2 rows x 4 replications) 6 Iowa State Node-Injury scale (0-3). Number of full or partial nodes completely eaten 7 Product consistency = Percentage of times nodal injury was 0.25 (¼ node eaten) or less

8 Significant difference between the treatment means for Node-Injury (ANOVA, P < 0.05); No significant difference between the treatment means for Product Consistency (ANOVA, P ≥ 0.05)

Table 2. Average Root Injury and Product Consistency for Insecticide on Non-RW Bt Corn: Johnson Farm, Story County1

Treatment2 Rate³ Placement4 Node- Injury5,6,8

Product Consistency7,8

MBI-3P1b

0.40 Seed Trt 1.60a 5

MBI-306 SC1 0.20 Seed Trt 1.61a 0

MBI-306 SC1

0.40 Seed Trt 1.64a 10

MBI-306 SC1

0.10 Seed Trt 1.77ab 10

Abamectin + Thiamethoxam

1.25 Seed Trt 1.81abc 10

Untreated

------ --------- 1.87abcd 5

MBI-306 SC1

0.05 Seed Trt 1.88abcd 0

MBI-306 SC1


MBI-206 BM3SE1


MBI-3P1b


MBI-3P1b


MBI-3P1b


MBI-3P1b

0.60 Seed Trt 2.17bcd 0

MBI-3P1b

0.80 Seed Trt 2.31cd 0

MBI-306 SC1 0.80 Seed Trt 2.37d 0

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Table 3. Average Stand Count for Insecticide on Non-RW Bt Corn: Johnson Farm, Story County1

1 Planted April 29, 2020; evaluated May 20 and September 22, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Non-RW Bt = Seed provided by MBI 3 All Insecticides listed as fluid ounces per 100 lbs. of seed

4 Seed treatments were applied to seed coat before planting 5 Data presented as plants per 1/1000 of an acre 6 Significant difference between the treatment means (ANOVA, P < 0.05)

Treatment2 Rate³ Placement4 Stand Counts5,6

MBI-306 SC1

0.05 Seed Trt 32.8a

Untreated

------ --------- 31.5ab

MBI-306 SC1

0.60 Seed Trt 31.2abc

MBI-3P1b


MBI-3P1b

0.80 Seed Trt 31.0bcd

MBI-3P1b




MBI-3P1b


MBI-3P1b


MBI-306 SC1 0.20 Seed Trt 30.3bcd

MBI-306 SC1


MBI-206 BM3SE1


MBI-306 SC1


MBI-306 SC1

0.10 Seed Trt 29.7cd

MBI-3P1b 0.10 Seed Trt 29.3d

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Table 4. Average Yield for Insecticide on Non-RW Bt Corn: Johnson Farm, Story County1

1 Planted April 29, 2020; machine harvested October 16, 2020 for crop destruct 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Non-RW Bt = Seed provided by MBI 3 All Insecticides listed as fluid ounces per 100 lbs. of seed

4 Seed treatments were applied to seed coat before planting 5 Means based on 4 observations (4-row treatment x 30 row-feet/treatment x 4 replications) 6 Significant differences between the treatment means (ANOVA, P < 0.05) 7 Yields converted to 15.5% Moisture

Treatment2 Rate3 Placement4 Bushels/Acre5,6,7

MBI-306 SC1

0.60 Seed Trt 180.9a

MBI-306 SC1

0.40 Seed Trt 175.4ab

MBI-306 SC1 0.20 Seed Trt 175.1ab

Untreated

------ --------- 174.6ab

MBI-3P1b

0.40 Seed Trt 173.3ab

MBI-3P1b


MBI-306 SC1


MBI-206 BM3SE1




MBI-3P1b

0.10 Seed Trt 155.5abcd

MBI-3P1b


MBI-306 SC1


MBI-306 SC1


MBI-3P1b

0.60 Seed Trt 142.9cd

MBI-3P1b 0.80 Seed Trt 136.1d

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1 Planted April 29, 2020 evaluated July 21, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Non-RW Bt = Seed provided by Valent 3 Force CS, Ampex SC 2055, and Capture LFR listed as fluid ounces per 1000 row feet; Aztec listed as ounces per 1000 row feet; Poncho listed as milligrams of a.i. per seed

4 Furrow = insecticide applied in furrow at planting time; Seed Treatment = insecticide applied to seed coat before planting 5 Means based on 20 observations (5 roots/2 rows x 4 replications) 6 Iowa State Node-Injury scale (0-3). Number of full or partial nodes completely eaten 7 Product consistency = Percentage of times nodal injury was 0.25 (¼ node eaten) or less

8 Significant difference between the treatment means for both Node-Injury and Product Consistency (ANOVA, P < 0.05)

Table 5. Average Root Injury and Product Consistency for Insecticide on Non-RW Bt Corn: Johnson Farm, Story County1

Treatment2 Formulation Rate³ Placement4 Node- Injury5,6,8


Aztec

2.10 GR 6.70 Furrow 0.59a 20ab

Force CS

2.10 SC 0.57 Furrow 0.96ab 25a

Ampex SC 2055

1.71 SC 0.46 Furrow 1.09bc 0b

Poncho

600 FS 1.25 Seed Trt 1.14bcd 20ab

Ampex SC 2055

1.71 SC 0.69 Furrow 1.24bcd 5ab

Ampex SC 2055


Capture LFR


Poncho

600 FS 0.50 Seed Trt 1.44cd 5ab

Check ------ ------ ---------- 1.51d 0b

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Table 6. Average Stand Count for Insecticide on Non-RW Bt Corn: Johnson Farm, Story County1

1 Planted April 29, 2020; evaluated May 20 and September 22, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Non-RW Bt = Seed provided by Valent 3 Force CS, Ampex SC 2055, and Capture LFR listed as fluid ounces per 1000 row feet; Aztec listed as ounces per 1000 row feet; Poncho listed as milligrams of a.i. per seed

4 Furrow = insecticide applied in furrow at planting time; Seed Treatment = insecticide applied to seed coat before planting 5 Data presented as plants per 1/1000 of an acre

6 Significant difference between the treatment means (ANOVA, P < 0.05)

Treatment2 Formulation Rate³ Placement4 Stand Counts5,6

Force CS

2.10 SC 0.57 Furrow 29.6a

Ampex SC 2055

1.71 SC 0.69 Furrow 29.4ab

Aztec

2.10 GR 6.70 Furrow 28.8ab

Ampex SC 2055

1.71 SC 0.46 Furrow 28.8ab

Capture LFR

1.50 SC 0.98 Furrow 28.5ab

Check

------ ------ ---------- 28.4ab

Poncho

600 FS 1.25 Seed Trt 28.2ab

Ampex SC 2055

1.71 SC 0.86 Furrow 27.6ab

Poncho 600 FS 0.50 Seed Trt 27.5b

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Table 7. Average Yield for Insecticide on Non-RW Bt Corn: Johnson Farm, Story County1

1 Planted April 29, 2020; machine harvested October 16, 2020 for crop destruct 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Non-RW Bt = Seed provided by Valent 3 Force CS, Ampex SC 2055, and Capture LFR listed as fluid ounces per 1000 row feet; Aztec listed as ounces per 1000 row feet; Poncho listed as milligrams of a.i. per seed

4 Furrow = insecticide applied in furrow at planting time; Seed Treatment = insecticide applied to seed coat before planting 5 Means based on 4 observations (4-row treatment x 30 row-feet/treatment x 4 replications) 6 Significant differences between the treatment means (ANOVA, P < 0.05) 7 Yields converted to 15.5% Moisture

Treatment2 Formulation Rate3 Placement4 Bushels/Acre5,6,7

Ampex SC 2055

1.71 SC 0.46 Furrow 175.9a

Capture LFR

1.50 SC 0.98 Furrow 168.8ab

Aztec

2.10 GR 6.70 Furrow 168.5ab

Force CS

2.10 SC 0.57 Furrow 164.6ab

Ampex SC 2055

1.71 SC 0.86 Furrow 161.9ab

Poncho

600 FS 1.25 Seed Trt 159.4ab

Ampex SC 2055

1.71 SC 0.69 Furrow 154.6ab

Poncho

600 FS 0.50 Seed Trt 149.5b

Check ------ ------ ---------- 146.6b

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1 Planted April 29, 2020 evaluated July 21, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Pioneer non-RW Bt = Pioneer AcreMax (P1151 AM); DeKalb SSTX

= Dekalb brand Smartstax RIB (DKC 62-52); Pioneer AMXT = Pioneer AcreMax Xtreme (P1197 AMXT); Syngenta Duracade = (G12W66-5222-EZ1)

3 All Insecticides listed as ounces per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Means based on 20 observations (5 roots/2 rows x 4 replications) 6 Iowa State Node-Injury scale (0-3). Number of full or partial nodes completely eaten 7 Product consistency = Percentage of times nodal injury was 0.25 (¼ node eaten) or less

8 Significant difference between the treatment means for both Node-Injury and Product Consistency (ANOVA, P < 0.05)

Table 8. Average Root Injury and Product Consistency for Insecticide on RW Bt Corn: Johnson Farm, Story County1



Dekalb SSTX

------ ------ --------- 0.03a 100a

Dekalb SSTX + Aztec HC

9.34 GR 1.50 Furrow 0.05a 100a

Pioneer AMXT + Aztec HC

9.34 GR 1.50 Furrow 0.07a 100a

Syngenta Duracade + Aztec HC

9.34 GR 1.50 Furrow 0.07a 90a

Pioneer AMXT

------ ------ --------- 0.08a 90a

Pioneer AM + Aztec HC

9.34 GR 1.50 Furrow 0.12a 85a

Syngenta Duracade

------ ------ --------- 0.14a 90a

Pioneer AM ------ ------ --------- 0.46b 50b

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Table 9. Average Stand Count for Insecticide on RW Bt Corn: Johnson Farm, Story County1

1 Planted April 29, 2020 evaluated May 29, 2020 and September 22, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Pioneer non-RW Bt = Pioneer AcreMax (P1151 AM); DeKalb SSTX


3 All Insecticides listed as ounces per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Data presented as plants per 1/1000 of an acre 6 Significant difference between the treatment means (ANOVA, P < 0.05)


Syngenta Duracade

------ ------ --------- 32.4a

Dekalb SSTX

------ ------ --------- 32.1ab


9.34 GR 1.50 Furrow 32.1ab


9.34 GR 1.50 Furrow 31.4ab

Pioneer AM

------ ------ --------- 31.3ab

Pioneer AMXT

------ ------ --------- 31.1ab


9.34 GR 1.50 Furrow 30.4ab

Syngenta Duracade + Aztec HC 9.34 GR 1.50 Furrow 29.1b

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Table 10. Average Yield for Insecticide on RW Bt Corn: Johnson Farm, Story County1

1 Planted April 29, 2020; machine harvested October 16, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Pioneer non-RW Bt = Pioneer AcreMax (P1151 AM); DeKalb SSTX


3 All Insecticides listed as ounces per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Means based on 4 observations (4-row treatment x 30 row-feet/treatment x 4 replications) 6 Significant differences between means (ANOVA, P < 0.05) 7 Yields converted to 15.5% Moisture

1 Planted May 11, 2020 evaluated July 28, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Dekalb non-RW Bt = Dekalb VT2P RIB (DKC 62-98) 3 All treatments used Nucleus HP 8-24-4 fertilizer as a carrier 4 All Insecticides listed as fluid ounces per 1000 row feet 5 Furrow = insecticide applied in furrow at planting time 6 Means based on 20 observations (5 roots/2 rows x 4 replications) 7 Iowa State Node-Injury scale (0-3). Number of full or partial nodes completely eaten 8 Product consistency = Percentage of times nodal injury was 0.25 (¼ node eaten) or less

9 Significant difference between the treatment means for Node-Injury (ANOVA, P < 0.05); No Significant difference between the treatment means for Product Consistency (ANOVA, P ≥ 0.05)


Pioneer AMXT

------ ------ --------- 224.4a


9.34 GR 1.50 Furrow 218.5a


9.34 GR 1.50 Furrow 209.5ab

Dekalb SSTX

------ ------ --------- 200.7abc

Pioneer AM

------ ------ --------- 190.5bcd


9.34 GR 1.50 Furrow 186.5bcd

Syngenta Duracade + Aztec HC

9.34 GR 1.50 Furrow 183.5cd

Syngenta Duracade ------ ------ --------- 175.1d

Table 11. Average Root Injury and Product Consistency for Insecticide on Non-RW Bt Corn: Bruner Farm, Boone County1

Treatment2,3 Formulation Rate4 Placement5 Node- Injury6,7,9


Check

------ ------ --------- 0.16a 80

Force EVO

2.10 EC 0.57 Furrow 0.17a 80

Ampex E-Z

1.71 SC 0.69 Furrow 0.18a 70

Index

2.80 CS 0.72 Furrow 0.24ab 65

Capture LFR 1.50 SC 0.98 Furrow 0.30b 50

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Table 12. Average Stand Count for Insecticide on Non-RW Bt Corn: Bruner Farm, Boone County1

1 Planted May 11, 2020; evaluated June 8 and September 24, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Dekalb non-RW Bt = Dekalb VT2P RIB (DKC 62-98) 3 All treatments used Nucleus HP 8-24-4 fertilizer as a carrier 4 All Insecticides listed as fluid ounces per 1000 row feet 5 Furrow = insecticide applied in furrow at planting time

6 Data presented as plants per 1/1000 of an acre 7 Significant difference between the treatment means (ANOVA, P < 0.05) Table 13. Average Yield for Insecticide on Non-RW Bt Corn: Bruner Farm, Boone County1

1 Planted May 11, 2020; machine harvested October 21, 2020 for crop destruct 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Dekalb non-RW Bt = Dekalb VT2P RIB (DKC 62-98) 3 All treatments used Nucleus HP 8-24-4 fertilizer as a carrier 4 All Insecticides listed as fluid ounces per 1000 row feet 5 Furrow = insecticide applied in furrow at planting time

6 Means based on 4 observations (4-row treatment x 30 row-feet/treatment x 4 replications) 7 No significant differences between means (ANOVA, P ≥ 0.05) 8 Yields converted to 15.5% Moisture

Treatment2,3 Formulation Rate4 Placement5 Stand Counts6,7

Check ------ ------ --------- 32.5a

Capture LFR

1.50 SC 0.98 Furrow 31.7ab

Force EVO

2.10 EC 0.57 Furrow 31.6ab

Index

2.80 CS 0.72 Furrow 31.1ab

Ampex E-Z 1.71 SC 0.69 Furrow 30.0b

Treatment2,3 Formulation Rate4 Placement5 Bushels/Acre6,7,8

Force EVO

2.10 EC 0.57 Furrow 212.8

Index

2.80 CS 0.72 Furrow 212.5

Check ------ ------ --------- 208.7

Capture LFR

1.50 SC 0.98 Furrow 202.5

Ampex E-Z 1.71 SC 0.69 Furrow 190.3

18

1 Planted May 11, 2020 evaluated July 28, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Dekalb non-RW Bt = Dekalb VT2P RIB (DKC 62-98) 3 Ethos XB, Xyway, and Capture LFR listed as fluid ounces per 1000 row feet; Force 3G listed as ounces per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Means based on 20 observations (5 roots/2 rows x 4 replications) 6 Iowa State Node-Injury scale (0-3). Number of full or partial nodes completely eaten 7 Product consistency = Percentage of times nodal injury was 0.25 (¼ node eaten) or less



1 Planted May 11, 2020; evaluated June 8 and September 24, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Dekalb non-RW Bt = Dekalb VT2P RIB (DKC 62-98) 3 Ethos XB, Xyway, and Capture LFR listed as fluid ounces per 1000 row feet; Force 3G listed as ounces per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Data presented as plants per 1/1000 of an acre 6 Significant difference between the treatment means (ANOVA, P < 0.05)




Force

3.00 GR 5.00 Furrow 0.19a 65

Ethos XB

1.50 SC 0.73 Furrow 0.25ab 60

Xyway

2.50 SC 0.44 Furrow 0.27ab 70

Xyway

2.50 SC 0.87 Furrow 0.28ab 55

Ethos XB

1.50 SC 0.49 Furrow 0.29ab 50

Capture LFR

1.50 SC 0.73 Furrow 0.32ab 45

Capture LFR

1.50 SC 0.49 Furrow 0.34ab 40

Untreated ------ ------ --------- 0.39b 40


Capture LFR

1.50 SC 0.73 Furrow 33.0a

Xyway

2.50 SC 0.44 Furrow 32.8ab

Force

3.00 GR 5.00 Furrow 32.6ab

Untreated

------ ------ --------- 32.4ab

Ethos XB

1.50 SC 0.49 Furrow 32.2ab

Capture LFR

1.50 SC 0.49 Furrow 31.8ab

Xyway

2.50 SC 0.87 Furrow 31.6ab

Ethos XB 1.50 SC 0.73 Furrow 31.1b

19

Table 16. Average Yield for Insecticide on Non-RW Bt Corn: Bruner Farm, Boone County1

1 Planted May 11, 2020; machine harvested October 21, 2020 for crop destruct 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Dekalb non-RW Bt = Dekalb VT2P RIB (DKC 62-98) 3 Ethos XB, Xyway, and Capture LFR listed as fluid ounces per 1000 row feet; Force 3G listed as ounces per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Means based on 4 observations (4-row treatment x 30 row-feet/treatment x 4 replications) 6 No Significant differences between means (ANOVA, P ≥ 0.05) 7 Yields converted to 15.5% Moisture


Capture LFR

1.50 SC 0.73 Furrow 211.9

Capture LFR

1.50 SC 0.49 Furrow 207.4

Ethos XB

1.50 SC 0.49 Furrow 206.8

Ethos XB

1.50 SC 0.73 Furrow 202.8

Xyway

2.50 SC 0.44 Furrow 195.5

Untreated

------ ------ --------- 194.7

Xyway

2.50 SC 0.87 Furrow 193.4

Force 3.00 GR 5.00 Furrow 190.6

20

1 Planted May 12, 2020 evaluated July 29, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Viking non-RW Bt = (53-12 GS-UNT) 3 All Insecticides listed as fluid oz. per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Means based on 20 observations (5 roots/2 rows x 4 replications) 6 Iowa State Node-Injury scale (0-3). Number of full or partial nodes completely eaten 7 Product consistency = Percentage of times nodal injury was 0.25 (¼ node eaten) or less



Treatment2 Rate³ Placement4 Node- Injury5,6,8


Untreated

------ --------- 0.30a 45

Bifender

0.34 Furrow 0.30a 55

Force EVO

0.57 Furrow 0.31a 65

VCP-031 0.46 Furrow 0.33a 40

MBI-306 SE1 + Bifender

0.60 + 0.34 Furrow 0.34a 40

VCP-031

0.91 Furrow 0.36ab 45

MBI-306 SE1

0.90 Furrow 0.38ab 40

MBI-306 SE1

1.20 Furrow 0.40ab 50


0.60 + 0.84 Furrow 0.40ab 50

Bifender

0.84 Furrow 0.42ab 45

MBI-306 SE1 0.60 Furrow 0.54b 35

21


1 Planted May 12, 2020; evaluated June 8 and September 29, 2020 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Viking non-RW Bt = (53-12 GS-UNT) 3 All Insecticides listed as fluid oz. per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Data presented as plants per 1/1000 of an acre 6 Significant difference between the treatment means (ANOVA, P < 0.05) 7Treatments Bifender(0.34 rate), MBI-306 SE1(0.60 rate), MBI-306 SE1(0.60 rate) + Bifender(0.34 rate), MBI-306 SE1(0.60 rate) +

Bifender(0.84 rate), VCP-031(0.91 rate), and Force EVO had reduced stand counts in the first block due to standing water

Treatment2 Rate³ Placement4 Stand Counts5,6,7

VCP-031 0.46 Furrow 30.9a

MBI-306 SE1

1.20 Furrow 30.4ab

Untreated

------ --------- 30.3ab

MBI-306 SE1

0.90 Furrow 30.3ab

Bifender

0.84 Furrow 30.1ab

Force EVO

0.57 Furrow 30.1ab

MBI-306 SE1

0.60 Furrow 28.8abc


0.60 + 0.84 Furrow 28.3abcd


0.60 + 0.34 Furrow 27.5bcd

VCP-031

0.91 Furrow 26.8cd

Bifender 0.34 Furrow 25.7d

22

Table 19. Average Yield for Insecticide on Non-RW Bt Corn: Bruner Farm, Boone County1

1 Planted May 12, 2020; machine harvested October 21, 2020 for crop destruct 2 Non-RW Bt = an absence of any Bt trait targeting corn rootworm; Viking non-RW Bt = (53-12 GS-UNT) 3 All Insecticides listed as fluid oz. per 1000 row feet 4 Furrow = insecticide applied in furrow at planting time 5 Means based on 4 observations (4-row treatment x 30 row-feet/treatment x 4 replications), Treatments Bifender(0.34 rate), MBI-306

SE1(0.60 rate), MBI-306 SE1(0.60 rate) + Bifender(0.34 rate), MBI-306 SE1(0.60 rate) + Bifender(0.84 rate), VCP-031(0.91 rate), and Force EVO had 3 replications instead of 4 due to poor stand in the first block

6 Significant differences between means (ANOVA, P < 0.05) 7 Yields converted to 15.5% Moisture

Treatment2 Rate3 Placement4 Bushels/Acre5,6,7

Bifender

0.84 Furrow 204.5a


0.60 + 0.84 Furrow 196.7ab

Untreated

------ --------- 193.8ab

VCP-031

0.91 Furrow 193.7ab

Force EVO

0.57 Furrow 193.4ab

MBI-306 SE1

1.20 Furrow 191.8ab

MBI-306 SE1

0.60 Furrow 191.4ab

Bifender

0.34 Furrow 186.6ab


0.60 + 0.34 Furrow 180.8ab

VCP-031 0.46 Furrow 179.2ab

MBI-306 SE1 0.90 Furrow 169.5b

23

Table 20. Average Stand and Cut Plants in Black Cutworm Study: Johnson Farm, Story County1

1 Planted May 8, 2020; Stand Count conducted May 27, 2020; first Cut Plant evaluation conducted June 3, 2020; final Cut Plant evaluation conducted June 11, 2020

2 Seed provided by Valent 3 Ampex SC (2055) and Capture LFR listed as fluid oz. per 1000 row feet; NIPSIT(VC2100) listed as milligrams of a.i. per seed

4 Furrow = insecticide applied in furrow at planting time; Seed Trt = applied to seed coat prior to planting 5 Number of plants contained in metal black cutworm barrier 6 No Significant differences between means for Stand Counts and final Cut Plant evaluation (ANOVA, P ≥ 0.05); Significant difference

in between means for the first Cut Plant evaluation (ANOVA, P < 0.05)

Table 21. Average Yield in Black Cutworm Study: Johnson Farm, Story County1

1 Planted May 8, 2020; machine harvested October 16, 2020 for crop destruct 2 Seed provided by Valent 3 Ampex SC(2055) and Capture LFR listed as fluid oz. per 1000 row feet; NIPSIT(VC2100) listed as milligrams of a.i. per seed

4 Furrow = insecticide applied in furrow at planting time; Seed Trt = applied to seed coat prior to planting 5 Means based on 4 observations (2-row treatment x 30 row-feet/treatment x 4 replications) 6 No significant differences between means (ANOVA, P ≥ 0.05) 7 Yields converted to 15.5% Moisture


Cut Plants6

Cut Plants6

NIPSIT(VC2100) + Ampex SC(2055)

5.00 FS + 1.71 SC

1.25 + 0.46

Seed Trt + Furrow 23.0 3.5b 4.3

NIPSIT(VC2100)

5.00 FS

0.50

Seed Trt

23.3

4.8ab

7.0

Check

------

------

---------

24.0

5.5ab

7.0

NIPSIT(VC2100)

5.00 FS

1.25

Seed Trt

24.8

6.0ab

5.8

Capture LFR

1.50 SC

0.98

Furrow

23.5

6.3ab

7.0

Ampex (VC-2055)

1.71 SC

0.86

Furrow

25.5

7.3a

6.5


5.00 FS +

1.71 SC

0.50 +

0.69

Seed Trt +

Furrow

23.5

7.8a

6.5


NIPSIT(VC2100)

5.00 FS 1.25 Seed Trt 223.0

NIPSIT(VC2100)

5.00 FS 0.50 Seed Trt 218.3

Ampex (VC-2055)

1.71 SC 0.86 Furrow 217.4

Capture LFR

1.50 SC 0.98 Furrow 215.0


5.00 FS + 1.71 SC

0.50 + 0.69

Seed Trt + Furrow 214.4


5.00 FS + 1.71 SC

1.25 + 0.46

Seed Trt + Furrow 209.8

Check ------ ------ --------- 206.0

24

APPENDIX I

Agronomic Information

25

2020 Field History Data

Story County, IA-ISU Johnson Farm Boone County, IA-ISU Bruner Farm Corn Rootworm Studies Corn Rootworm Studies (following trap crop) (following trap crop) Insecticide History 2019 Corn (trap crop) Corn (trap crop) 2018 Corn (field plots) Corn (field plots) 2017 2016

Corn (trap crop) Corn (field plots)

Corn (trap crop) Corn (field plots)

2015 Corn (trap crop) Corn (trap crop) Tillage Fall 2019-Corn stalks disk ripped

Spring 2020-field cultivation (2X) Fall 2019-Deep rip; Spring 2020-field cultivation (2X)

Variety

Pioneer P1151AM Dekalb DKC 62-52 SS RIB Pioneer P1197 AMXT Syngenta G12W66-5222-EZ1

Dekalb DKC 62-98 RIB VT2P Viking 53-12 GS-UNT

Planting Date April 29, May 8 May 11, May 12 Planting Rate 35,600 seeds/A 35,600 seeds/A Herbicides

2.5 pints/acre Surestart II -April 22-PRE; 3 oz/acre Capreno & 12 oz/acre Atrazine-June 12-POST

15 oz/acre Verdict-May 16-PRE; 1 oz/acre Impact-July 2-POST 6 oz/acre Buctril-July 2-POST

Fertilizer1

N P K S Zn

N P K S Zn

Fall/2018 Preplant

17.5 70 130 - - 200

24 80 120 20 2 200

Dates Stand Count May 20, May 29, September 22 June 8, September 24, September 29 Root Digging July 21, July 23 July 28, July 29 Harvest October 16 October 21 Soil Type Clay loam & loam Silty clay loam Soil Organic Matter % 3.4 3.5 Soil pH 5.7 6.1 1 ISU Johnson Farm (Story County) Spring-preplant 200 lbs. actual N in 32% UAN form applied late April at ISU Johnson Farm (Ames); Fall/2019 applied- 17.5 lbs. Nitrogen, 70 lbs. Phosphorus, 130 lbs. Potassium applied; ISU Bruner Farm (Boone County) MESZ phosphorus applied May 31 at 200 lbs/A, Potash on April 1 at 200 lbs/A analysis of these applications showed 24-80-120-20-2, 32% UAN applied at 200 lbs/A on May 1

26

APPENDIX II

Weather Data

27

1. Weather station located 5 miles WSW of Ames at ISU AEA/Agronomy Farm. Low/High Temperatures & Rainfall amounts for Ames & Boone from Mesonet Weather Station website at: http://mesonet.agron.iastate.edu/agclimate/

Ames & Boone¹ 2020 Rainfall and Temperature

April May June

Day Temp.(F°) Precip.

(inches)


(inches)


(inches) High Low High Low High Low 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

61 63 61 44 60 63 81 81 55 52 52 49 40 39 39 40 47 66 68 66 67 77 76 67 66 69 78 79 63 69

34 35 27 22 29 42 54 50 28 22 37 32 22 21 15 15 15 34 40 37 33 46 45 49 42 43 49 53 46 44

0.10

0.09 0.91

0.05

0.13

0.12

0.09

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

81 80 77 75 54 59 62 61 67 64 56 58 60 63 71 74 73 58 60 62 61 71 71 81 80 77 76 77 74 71 72

48 56 50 49 43 42 42 36 32 39 41 38 42 52 49 50 54 50 51 56 55 55 60 60 64 65 65 63 53 51 57

0.45

0.02 0.02

0.02 0.32 0.07

1.39 0.06

0.55 0.03 0.29 1.74 0.19 0.13

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

88 94 94 91 90 86 90 90 90 74 82 86 86 79 86 86 85 86 86 79 87 86 72 79 84 84 84 86 85 86

63 69 67 70 65 66 69 72 67 58 55 60 61 56 64 64 60 66 67 64 64 63 58 56 58 71 69 68 75 73

0.06

0.21 0.23

0.27

0.80

Temp. Avg.

61.3 35.4 Total(in.) Temp. Avg.


85.4 64.6 Total(in.) 48.3 1.49 59.4 5.28 75.0 1.57

Normal 61.5 4.80 Normal 71.0 4.96 Normal 74.0 4.84 D.F.N. -13.2 -3.31 D.F.N -11.6 0.32 D.F.N. 1.0 -3.27

28



July August September


(inches)


(inches)


(inches) High Low High Low High Low 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

82 88 88 87 89 89 90 93 92 87 88 85 86 86 87 81 87 90 85 81 81 81 82 90 92 90 84 86 88 88 81

70 68 62 58 53 57 70 71 71 62 67 63 64 69 63 56 66 76 71 68 65 62 61 67 72 74 66 62 67 66 61

0.42

1.80

0.04

0.14

0.33

0.06

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

81 80 74 73 73 76 84 88 88 88 80 84 87 86 85 86 86 78 80 83 86 88 92 93 94 93 93 94 91 78 78

57 66 53 50 52 61 63 68 68 60 56 64 72 68 62 60 63 56 56 58 59 66 65 69 67 67 69 48 56 54 59

0.04

0.13

0.71

0.12

0.02

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

76 88 88 83 85 90 91 67 49 52 58 66 77 79 83 82 74 69 69 73 80 80 79 81 85 88 88 62 63 67

53 57 65 49 53 68 53 45 44 46 51 56 49 53 55 58 47 44 47 47 50 52 53 59 60 60 56 47 45 47

0.03

0.33 1.49 0.75 0.27 0.19 0.02

0.06 0.05

Temp. Avg.



75.7 52.3 Total(in.) 76.0 2.79 72.9 1.02 64.0 3.19

Normal 72.5 4.80 Normal 65.0 3.27 Normal 52.5 2.60 D.F.N. 3.5 -2.01 D.F.N. 7.9 -2.25 D.F.N. 11.5 0.59

29



October


(inches)


(inches)


(inches) High Low High Low High Low 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

64 56 56 58 73 81 80 78 86 85 80 79 64 70 68 51 65 63 43 39 45 48 46 37 37 31 39 58 57 49 64

46 33 43 34 40 48 53 46 57 50 55 48 46 46 34 29 42 32 20 32 36 43 33 20 30 20 11 26 30 24 18

0.16 0.03

0.55 0.33

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Temp. Avg.


Total(in.) Temp. Avg.

Total(in.) 47.8 1.07

Normal 37.5 2.05 Normal Normal D.F.N. 10.3 -0.98 D.F.N. D.F.N.

30

APPENDIX III

Materials Tested

31

Table 1. Commercial insecticides used in studies in 2020

Table 2. Rootworm active Bt Traits

Product name

Rate (ounces per 1000 row-feet; unless specified) Active ingredient Company

Aztec 2.1G 6.70 tebupirimphos & cyfluthrin AMVAC Chem. Corp.

Aztec HC 1.50 tebupirimphos & cyfluthrin AMVAC Chem. Corp.

Bifender 0.34 & 0.84 bifenthrin Vive Crop Protection Inc.

Capture LFR 0.49, 0.73, & 0.98 bifenthrin FMC

Ethos XB 0.49 & 0.73 bifenthrin FMC

Force 3G 5.00 tefluthrin Syngenta

Force CS 0.57 tefluthrin Syngenta

Force EVO 0.57 tefluthrin Syngenta

Index 0.72 chlorethoxyfos & bifenthrin AMVAC Chem. Corp.

Poncho 0.50 & 1.25 mg ai/seed clothianidin Bayer Crop Science

Xyway 0.44 & 0.87 flutriafol FMC

Product name Events targeting rootworm Toxin Company

Agrisure Duracade 5307 + MIR604 eCry3.1Ab + mCry3A Syngenta

Pioneer AMXT DAS-59122-7 + MIR604 Cry34/35Ab1 + mCry3A Corteva

Smartstax RIB DAS-59122-7 + MON 88017 Cry34/35Ab1 + Cry3Bb1 Bayer & Corteva

32

APPENDIX IV 2020 Research Photos

Assembling black cutworm barriers at Johnson Research Farm located near Ames, Iowa. From left to right Leslie Du, Ryan Meehan, and Lydia Holmes

Conducting late season stand counts at Bruner Research Farm located between Ames and Boone, Iowa.

Documents

2020 IOWA EVALUATION OF INSECTICIDES AND PLANT