- 2 -

RECOMMENDATIONS AND CONCLUSIONS

1. Grower On-Line Survey: Grower Compliance and IRM Awareness

a) BPPD concurs with ABSTC that the majority of growers who planted single trait ECB PIP products were

compliant with the refuge requirements in 2010 when national average results from the on-line survey were 

considered (76% for refuge size; 87% for refuge distance) . Compliance among growers planting CRW 

protected PIPs was low and unchanged from the reported 2009 results. Compliance percentages for stacked 

PIP products have now reached an all time low (69% for refuge size; 63% for refuge distance), yet based on 

the standard error provided, these differences were not statistically significant from the 2009 results.

Nonetheless, BPPD is concerned about these compliance numbers, especially considering that surveyed 

growers could not demonstrated increased IRM knowledge in the online survey. On an unaided basis, only 

61% of the growers could recall the correct refuge size for ECB and only 56% recalled the correct refuge 

distance for the CRW portion of the stacked PIPs. This is a slight decline from an already low awareness in 

2009 of 66% and 59% for correct refuge size. These percentages are at an all time low; ABSTC has not 

been able to demonstrate that their educational efforts increase grower awareness with refuge requirements 

for stacked PIPs. It is recommended that ABSTC meet with BPPD to discuss future approaches in 

increasing IRM knowledge and compliance among growers planting stacked PIPs. 

b) When on-line compliance results were evaluated on a regional basis, it was evident (as in 2009) that 

southern corn growers (in cotton growing regions) were up to 2.2 more likely to get out of compliance than 

their northern counterparts. Possible explanations for lower levels of compliance in the south could include 

confusion with different requirements between various PIP products or simply blatant disregard of refuge 

requirements by growers who plant both Bt corn and Bt cotton. ABSTC stated in their 2009 CAP report that 

these regional results provided them with the opportunity to intensify future educational efforts in the 

southern corn growing regions. BPPD notes that if higher non-compliance among southern corn growers 

reflects a willingness to violate refuge requirements rather than a lack of knowledge, then increased 

educational efforts may not be fruitful. Other methods to bring these growers back into compliance may 

need to be considered. 

c) Furthermore, BPPD disagrees with ABSTC’s statement that the risk of resistance evolution may be lower in 

the south despite the greater non-compliance because only 10% of the corn production occurs in that region 

(cited from 2009 USDA data). Although higher Bt adoption in conjunction with non-compliance could be a 

strong driver for resistance evolution, it cannot be discounted that consistent local non-compliance with 

refuge requirements increases the risk of resistance evolution in such areas despite lower Bt corn adoption. 

Of greater importance for local non-compliance (resistance will likely be a local phenomenon initially) is 

the amount of refuge available at that scale, and the amount of immigration of refuge insects from other 

corn growing areas. Additional data or information would be needed to evaluate ABSTC’s claim of low 

potential risk of resistance evolution in the south (with less compliance and adoption of Bt corn).
- 3 -

2. On-Farm Assessments (First Time and Reassessment): Grower Compliance

a) Adherence to refuge requirements for growers planting ECB protected PIPs was high (86.6%), and 

significant violations were lower (8.4%) than reported for the 2009 season (10.8%). 

b) For growers planting CRW protected PIPs, adherence to refuge requirements was higher (84.5%) than for 

the 2009 growing season (69.1%), and significant violations were 50% lower than reported for 2009. The 

sample size for first-time on-farm assessments keeps decreasing each year. BPPD recommends that 

individual companies increase the sample size for CRW first-time assessment. A sample size of 50-60 

farmers is likely insufficient to acquire a good understanding of confirmed on-farm compliance with IRM 

requirements.

c) Adherence to refuge requirements for growers planting stacked PIPs was similar in 2010 (83.8%) to what 

was reported for the 2009 growing season (83.3%). Significant violations were lower in 2010 (8.8%) than 

reported for the 2009 season (10.8%).

d) BPPD is aware that companies do not share their clientele list with each other and that names and locations 

of non-compliant growers are kept confidential and anonymous. Yet, BPPD recommends that ABSTC 

compile and maintain, through a neutral third party, maps showing the distribution of on-farm noncompliance pooled across registrants so that it is clear to the EPA where regions of high non-compliance are 

located. It may then be possible for ABSTC to focus compliance efforts in these regions with increased 

educational outreach or other appropriate new measures.

e) ABSTC stated that one grower had his license revoked in 2010; however, their data (Table 8) showed that 

two growers had some significant violations with compliance requirements (one grower for ECB PIPs and 

another for stacked products - unless the same grower planted both a single and stacked product and 

committed a violation for both types of PIPs in 2010) and were denied access to the technology for 2011.

3. BPPD Recommended Changes To CAP

a) It is recommended that ABSTC address the newly approved refuge requirements in the 2010 CAP: 5% and 

20% structured refuge in the Corn Belt and cotton growing regions, respectively, for pyramided 

lepidopteran traits. Future survey results for 5% and 20% structured refuge in the Corn Belt should be 

separately collected, analyzed, and provided to BPPD (as for 20% and 50% structured refuge requirements 

in the cotton growing regions).

4. ABSTC Proposed Changes for 2011

a) ABSTC stated that beginning in 2011, the refuge requirements would be listed on seed bags, which 

should raise awareness and growers’ understanding of their IRM obligations.
- 4 -

I. BACKGROUND

As a condition of registration for the corn borer-protected Bt (Bacillus thuringiensis) corn products (EPA Reg. 

Nos. 524-489, 68467-2, 67979-1 and 29964-3), corn rootworm-protected Bt corn products (EPA Reg. Nos. 524-

528, 524-551, 68467-5, 67979-5, and 29964-4), and stacked (corn-borer/corn rootworm-protected) Bt corn 

products (EPA Reg. Nos. 524-545, 524-552, 524-576, 68467-6, 67979-8, and 29964-5), the registrants must 

work together through their self-appointed Agricultural Biotechnology Stewardship Technical Committee 

(ABSTC) to implement an Insect Resistance Management (IRM) Compliance Assurance Program (CAP). The 

IRM CAP is designed to promote compliance with refuge requirements among all Bt corn growers irrespective of 

farm size. The program is composed of several parts: grower agreements, annual grower affirmation of IRM 

requirements, grower education, tips and complaints to identify non-compliant growers, third-party grower 

survey (via telephone and, since 2007, only on-line), on-farm assessments and follow-up actions (phased 

compliance program) should non-compliant growers be identified through the on-farm assessments. Individual 

registrants, however, are responsible for implementing the requirements agreed upon by the ABSTC-Insect 

Resistance Management Stewardship Subcommittee’s Compliance Assurance Program and EPA. Yearly results 

of the program are to be reported to EPA in an annual compliance assurance report (due January 31st each year). 

This review addresses the 2010 Insect Resistance Management Compliance Assurance Program Report for Corn 

Borer-Protected Bt Corn submitted by the ABSTC - Insect Resistance Management Stewardship Subcommittee. 

II. SUMMARY OF 2010 CAP

The 2010 ABSTC CAP contained a summary of the following activities: 1) 2010 third party grower surveys for 

single and stacked PIPs targeting ECB and CRW, 2) 2010 on-farm assessments, 3) tips and complaints, and 4) 

CAP activities for 2010. Grower agreements and annual grower affirmation systems are reviewed as part of 

each registrant’s annual IRM report.

ABSTC stated that beginning in 2011, the refuge requirements would be listed on seed bags which should raise 

awareness and growers’ understanding of their IRM obligations.

1. CORN BORER-PROTECTED Bt CORN REGISTRATIONS

2010 Data

In 2010, of the 269 growers who completed the online survey for single ECB PIPs, 76% planted a 20% refuge 

and 87% complied with the 1⁄2 mile distance requirement (regional results). An additional 11% of growers 

planted > 15% refuge but less than 20%, and 5% of growers surveyed failed to plant a refuge at all. Responses to 

survey questions about 

:

each field on a grower’s farm revealed that 91% of all fields planted to corn borer 

protected Bt corn had a refuge planted within the required 1⁄2 mile distance. Three percent of all fields had a 

refuge beyond 1⁄2 mile, and 6% of all fields had no refuge associated with them. The compliance results listed for 

2011 (see Table 1) have a reported margin of error of ±6.0%.

On a regional basis, 71% and 81% of growers planted the correct refuge size and 83% and 90% adhered to the 

distance requirements in the eastern and western regions of the Corn Belt, respectively. In the cotton growing 

regions, 49% of growers met the refuge size requirements and 70% reported planting all of their fields within 
- 5 -

the appropriate distance. 

When growers were asked on an unaided basis what they recalled about IRM requirements, 65% and 82% 

correctly identified the refuge size and distance requirements, respectively.

Table 1. Summary of telephone survey results for corn borer-protected Bt corn growers (Data from 2002-2006) and online 

survey results (Data from 2007 and 2010)

Survey Question

Survey Year

Telephone Online

2002 2003 2004 2005 2006 2007 2008 2009 2010

-----------% respondents-----------

Adherence to Refuge Size

Weighted average across all four 

regions surveyed

86 92 91 92 89 80 78 74% 76%

NC/SC/SE MO/TN/MS

( 50% refuge in cotton-growing 

areas)

77 82 78 82 80

N/A N/A

40% 49%

E IA/N IL (20% refuge) 88 96 95 94

89-99 77% 

and 

76%6

71% 

and 

81%6

SD/MN/NE/W IA (20% refuge) 85 93 90 91

KS/OK/TX (20% refuge) [High 

Plains]

81 82 93 95 82

Adherence to Distance Requirements

Weighted average across all four 

Regions surveyed

89 93 96 96 96 884 884 79%5 87%

NC/SC/SE MO/TN/MS [Cotton

Region]

78 83 84 80 80

N/A N/A

63% 70%

E IA/N IL 95 96 96 97

89-99

84%

and

79%6

83%

and

90%6

SD/MN/NE/W IA 89 94 98 97

KS/OK/TX [High Plains] 79 92 94 94

Awareness of IRM Requirements

All growers 88 93 92 92 92 96 98 95% 94%

Unaided Recall of IRM Requirements

Refuge size (weighted average 

across all four regions surveyed)

42 52 53 59 N/A 633 793 64% 65%
- 6 -

Refuge distance (weighted average

across all four regions surveyed)

37 49 55 53 49 793 893 82% 82%

Refuge size (Corn Belt and High 

Plains) 1 61 N/A N/A N/A N/A

Refuge size (Cotton Belt)2 31 N/A N/A N/A N/A

1

Corn belt and high plains = Iowa, Illinois, South Dakota, Minnesota, Nebraska, Kansas, Oklahoma, Texas, i.e., three of four regions surveyed 2

Cotton belt = North Carolina, South Carolina, south-eastern Missouri, Tennessee, and Mississippi 3 Cotton Belt numbers are not separated from Corn Belt survey results 4 Percent reflects only those growers that could remember the layout of all their Bt fields; 447 out of 467 (95.7%) in 2007; 298 out of 317 (94%) in 

2008.

5 on a per field basis, adherence was 92% in 2009; 5% of the fields had no refuge. 6

States in the eastern region were primarily Indiana, Illinois, Wisconsin, Ohio, Michigan; states in the western region were primarily Iowa, Nebraska, 

Minnesota, South Dakota, Missouri, and Kansas..

2. CORN ROOTWORM-PROTECTED Bt CORN REGISTRATIONS

2010 Data

In 2010, of the 54 growers who completed the online survey coleopteran protected PIPs, 73% planted a 20% 

refuge and 67% planted a refuge within or adjacent to the Bt field. An additional 10% of growers planted > 15% 

refuge but less than 20%, and 9% of growers surveyed failed to plant a refuge at all. Responses to survey 

questions about 

:

each field on a grower’s farm revealed that 70% of all fields planted to corn rootworm protected

corn had a refuge planted within the required distance. An additional 12% of all fields had a refuge planted 

beyond the required distance, while 18% of the fields had no refuge at all. The compliance results listed for 

2011 (see Table 2) have a reported margin of error of ±13.3%.

When growers were asked on an unaided basis what they recalled about IRM requirements, 33% and 22% 

correctly identified the refuge size and distance requirements, respectively.
- 7 -

Table 2. Percent Respondents for Different Questions of Telephone (2005-2006) and Online Survey (2007-2010) for RootwormProtected Bt Corn Growers

Survey Question3 20051 20062 2007 2008 2009 2010

Adherence to Refuge 93% 89% 80% 74% 79% 73%

Adherence to Distance

Requirements

87% 82% 79% 63% 71%4 67%

Awareness of IRM 

Requirements

97% 93% 97% 96% 92% 97

Unaided recall of 

refuge size

51% 57% 63% 72% 58% 33%

Unaided recall of 

refuge distance

58% 55% 33% 34% 31% 22%

 1

YieldGard RW and YieldGard Plus corn growers 2

YieldGard RW, YieldGard Plus, Herculex RW, and Herculex XTRA corn growers. 3

Weighted average across all four regions surveyed 4 on a per field basis, adherence was 76% in 2009; 14% of the fields had no refuge.

3. STACKED Bt CORN REGISTRATIONS

2010 Data:

Of the 536 growers who completed the online survey for planted stacked Bt corn (for ECB and/or CRW 

control), 69% and 63% met the refuge size and distance requirement, respectively. An additional 10% planted 

>15% but less than 20% refuge and 12% of growers failed to plant a refuge at all. The compliance results 

reported in Table 3 had a margin of error of ±4.2 %. 

Responses to survey questions about each field on a grower’s farm revealed that 73% of all fields planted to 

corn borer protected Bt corn had a refuge planted within the required 1⁄2 mile distance. However, 13% of all 

fields had a refuge beyond 1⁄2 mile, and 14% of all fields had no refuge associated with them.

On a regional basis, 65% and 76% of growers planted the correct refuge in the eastern and western regions of 

the Corn Belt, respectively. Adherence to the distance requirements for ECB and CRW was 59% and 69%. In 

the cotton growing region, 32% of growers met the refuge size requirements and 37% adhered to the distance 

requirements. 

When growers were asked on an unaided basis what they recalled about IRM requirements, 61% and 56% 

correctly identified the refuge size for ECB and CRW, respectively. On an unaided basis, 82% and 27% of 

growers correctly identified the ECB and CRW distance requirements, respectively.
- 8 -

Table 3. Percent Respondents from Different Question of Telephone and On-Line Survey for Stacked Bt Corn Growers (Data 

from 2006-2010)

Survey Question

2006 2007 2008 2009 2010

Adherence to Refuge Size1 78% 70% 72%4 71% 69%

Adherence to Distance

Requirements

92% 66% 66%3 67%3 63%

Adherence to Refuge Size –

Eastern and western regions of the

Corn Belt

N/A N/A N/A 74% and 73% 65% and 76%

Adherence to Refuge Distance –

Eastern and western regions of the

Corn Belt

N/A N/A N/A 66% and 70% 59% and 69%

Adherence to Refuge Size –

Cotton growing regions N/A N/A N/A 32% 32%

Adherence to Refuge Distance –

Cotton growing regions N/A N/A N/A 31% 37%

Awareness of IRM Requirements 95% 96% 97% 95% 94%

Unaided recall of refuge size 59% 62% and 55%2 81% 66% and 59%2 61% and 56%2

Unaided recall of refuge distance

CRW

48% 39% 36% 32% 27%

Unaided recall of refuge distance

ECB

32% 77% 86% 83% 82%

1 Weighted average across all four regions surveyed

2 First number listed is for ECB and the second number for CRW refuge compliance.

3 on a per field basis, adherence was76% in 2008 and 78% in 2009

4 on a per field basis, adherence was 73%

BPPD REVIEW OF ON-LINE GROWER SURVEY RESULTS (2010)

The survey results (see Figure 1) show that average compliance with refuge distance requirements for ECB 

protected corn expressing single PIPs was significantly higher in 2010 than in the previous year (margin of error 

+6.0%); compliance with refuge size remained approximately equal compared to 2009. Growers reported to be 

out of compliance deviated from the 20% requirement in one way or another. Further analysis of noncompliance numbers revealed that most farmers (87%) planted a refuge that was at least 15%, and that 5% 

of farmers neglected to plant a refuge at all. A regional analysis revealed that growers planting single ECB 

PIP expressing corn in eastern regions of the Corn Belt were less compliant on average (71% for refuge size, 

83% for refuge requirement) than growers in the western regions (81% for refuge size and 90% for distance 

requirement). Growers in the southern U.S. had significantly lower adherence percentages than the Corn Belt

again; the 2010 analysis reveals, however, that compliance in the south has had a small, yet statistically, 

significant increase in compliance compared to 2009 (from 40% in 2009 to 49% in 2010 for refuge size; from 

63% in 2009 to 70% in 2010 for refuge distance). It is unclear whether the observed difference is due to the 
- 9 -

smaller sample size in the south, which was reduced by 60% compared to the sample size in the eastern and 

western regions of the US. However, compliance is still below an acceptable level in the south; possible 

explanations for such lower compliance in the south could include confusion with different requirements 

between various PIP products or simply blatant disregard of refuge requirements by growers who plant both Bt 

corn and Bt cotton. ABSTC stated in their 2009 CAP report that these regional results provided them with the

opportunity to intensify future educational efforts in the southern corn growing regions. BPPD notes that if 

higher non-compliance among southern corn growers reflects a willingness to violate refuge requirements rather 

than a lack of knowledge, then increased efforts to educate them may not be fruitful. Other methods to bring 

these growers back into compliance may need to be considered. 

Grower awareness with IRM requirements was high (94%), yet the number of growers who could recall the 

correct refuge size (65%) was significantly lower compared to the number of growers who recalled the correct 

refuge distance requirements (82%). These percentages are reflective of the compliance numbers from the 

online survey.

Figure 1 Compliance trend from 2002-2010 for growers planting single ECB PIPs

Overall compliance (per grower) with refuge requirements for single PIPs targeting CRW is displayed in Figure 

2. Average compliance in 2010 has again decreased compared to 2009 and is now at the level of compliance 

(73% for refuge size, 67% for refuge distance) similar to that reported in 2008. The margin of error reported for 

CRW PIP compliance data is ±13.3%, hence the difference measured between 2010 and 2009 compliance is not 

statistically significant. The percentage of growers blatantly disregarding refuge requirements in 2010 was 

again 9%, as in 2009. Eighteen percent (18%) of all corn rootworm protected fields had no refuge associated 

with them; this is an increase from the 14% reported in 2009.

 

Grower awareness with IRM requirements in 2010 was higher than in 2009, yet, the percentage of growers who 

could recall the refuge size and distance requirements was extremely low (33% and 22%, respectively). That is 

a drastic decline from an already low awareness in 2009 of 58% and 31% for correct refuge size and refuge 

distance. These percentages are now at an all time low. BPPD believes that this decline in grower knowledge is 

0

20

40

60

80

100

120

'02 '03 '04 '05 '06 '07 '08 '09 '10

% Compliance

Planting season

Compliance with refuge requirements for ECB protected 

corn PIPs

refuge size

refuge distance
- 10 -

reason for concern and somewhat reflective of the compliance numbers from the online survey. ABSTC’s 

educational efforts have been unsuccessful at increasing grower education with respect to CRW IRM 

requirements.

Figure 2 Compliance trend from 2005-2010 for growers planting single CRW PIPs

Overall compliance (per grower) with refuge requirements for stacked corn PIPs is displayed in Figure 3. In 

2010, the reported margin of error for adherence with requirements was again ±4.2%; therefore, BPPD 

concludes that the latest national average compliance results were similar to those reported in prior years. A 

regional analysis of survey results revealed that growers’ compliance in eastern regions of the US significantly 

declined: adherence to refuge size requirements was 74% in 2009 and declined to 65% in 2010; adherence to 

refuge distance was 66% in 2009 and declined to 59%. Compliance in the western regions of the Corn Belt 

remained similar or slightly higher to those reported in 2009. Corn growers in the cotton growing regions had 

similar compliance in 2010 as in 2009 – 32% and 37% for adherence to refuge size and distance requirements. 

BPPD notes that the compliance percentages in the south are extremely low. 

BPPD notes that the number of growers who were able to correctly recall IRM requirements on an unaided 

basis reached an all time low since 2007. Only 27% of growers were able to correctly recall the correct distance 

requirement for the CRW portion of the PIP in 2010. This represents a further decline from the reported 32% in 

2009. Only 56% of the growers surveyed recalled that refuge size for the CRW PIP was 20%. The increased 

educational outreach by ABSTC is not producing the expected results among corn growers planting stacked 

PIPs.

0

20

40

60

80

100

'05 '06 '07 '08 '09 '10

% Compliance

Planting season

Compliance with refuge requirements for CRW 

protected corn PIPs

refuge size

refuge distance
- 11 -

Figure 3 Compliance trend from 2006-2010 for growers planting stacked corn PIPs

Table 4 shows the percent of growers who have blatantly disregarded refuge requirements for the individual PIP 

products planted in 2009 and 2010. Unfortunately, this information was not provided to the Agency prior to 

2009 and no historical comparison can, therefore, be made yet.

Table 4. Percent growers planting a zero % refuge for stacked Corn PIPs (data from 2009-2010)

Product Type 20091 20101

Single ECB PIPs 7% 5%

Single CRW PIPs 9% 9%

Stacked ECB/CRW PIPs 11% 12% 1

Results are listed on a per grower (not per field) basis

4. ON-FARM ASSESSMENT PROGRAM

The on-farm assessment portion of the Compliance Assurance Program identifies individual non-compliant 

growers (large and small farms) and brings them back into compliance through the Phased Compliance 

Approach. This part of the CAP is believed to enhance registrant and seed dealer understandings of the 

obstacles that hinder grower implementation of IRM requirements. Unlike the online grower survey, the onfarm assessment program is not a statistical tool for measuring the level of adherence to the IRM requirements. 

Registrants and their seed company partners independently coordinate the on-farm assessment activities each 

0

20

40

60

80

100

'06 '07 '08 '09 '10

% Compliance

Planting season

Compliance with refuge requirements for stacked corn 

PIPs

refuge size

refuge distance
- 12 -

year. Growers receiving “first-time” on farm assessments (i.e. not assessed the previous year) were selected 

from individual company customer lists and included a range of farm sizes across a number of key states. 

Growers found to be out of compliance in 2009 received a follow-up on-farm assessment in 2010. 

Company representatives were trained to conduct on-farm assessments. Topics covered in these trainings 

included IRM requirements, messages that should be communicated to growers, follow-up actions if growers 

are found to be out of compliance and how to use the IRM assessment form. All assessment forms contained the 

same questions, but the introductory paragraphs and company representative sections were customized to suit 

the needs of each registrant. Registrants responded to all compliance deviations identified in the 2009 on-farm 

assessments according to the common set of standards outlined in theCAP. 

The number of growers of each type of Bt corn who were assessed varied due to the market size of each product 

type. In 2010, a total of 3160 growers received a first time assessment. 

In 2010, 488 growers were found to be out of compliance, of which 277 had significant deviations. All 

compliance deviations were responded to in accordance with the Phased Compliance Approach, including 

reassessment in 2009. One grower met the criterion for revocation of access to stacked Bt corn according to 

EPA requirements. All other growers who planted single and stacked ECB and CRW Bt corn and who were out 

of compliance in 2009 were either successfully brought back into compliance in 2009, or no longer farmed or 

planted Bt corn in 2010.

a. Registrant results for first time on-farm assessment –growers planting ECB protected PIPs

2010 Data:

Of the 830 growers planting corn borer protected Bt corn and having received a first-time on-farm assessment 

in 2010, 13.4% were non-compliant with refuge requirements. Of all the growers assessed, 8.4% had significant 

deviations (see Table 5). On-farm assessments were conducted across a range of farm sizes with approximately 

33% of growers categorized as “small growers” with less than 250 acres of corn. As with previous years, the 

data suggest that farm size should not be a selection criterion when trying to identify non-compliant growers.

Growers significantly out of compliance in 2010 will be reassessed during the 2011 growing season.
- 13 -

Table 5. Cumulative Results for the First-Time On-Farm Lepidopteran-Protected Bt Corn Assessments (Data for 2003-2010)

Issue addressed Number of growers

2003 2004 2005 2006 2007 2008 2009 2010

Growers assessed 1961 2130 2215 2020 2083 1312 1082 830

Compliant 

growers

1,789

(91%)

2032 

(95.4%)

2089

(94.3%)

1930

(95.5%)

1895

(91.0%)

1132

(86.3%)

905

(83.7%)

719

(86.6%)

Noncompliant

growers

172 

(9%)

98 

(4.6%)

126 

(5.7%)

90

(4.5%)

188

(9.0%)

180 

(13.7%)

177 

(16.4%)

111

(13.4%)

Refuge size

deviations* 64 (3%) 27 (1.3%) 33 (1.5%) 33 (1.6%) N/A N/A N/A N/A

Refuge distance

deviations 127 (7%) 69 (3.2%) 68 (3.1%) 64 (3.2%) N/A N/A N/A N/A

Insignificant

deviations 68 (4%) 59 (2.8%) 51 (2.3%) 45 (2.2%) 59 (2.8%)

46 

(3.5%)

60 

(5.6%)

41

(5.0%)

Significant

deviations2 104 (5%) 39 (1.8%) 75 (3.4%) 45 (2.2%)

129

(6.2%)

134

(10.2%)

117

(10.8%)

70

(8.4%)

1 Some growers had compliance deviations other than refuge size or distance or some growers may have had both a refuge size and a refuge distance 

deviation; thus, the total of refuge distance and size deviations does not equal the number of non-compliant growers. 2 Significant deviations are defined as: Bt corn grower who planted less than 15% non- Bt corn refuge (except in certain cotton growing areas in 

which case it would be less than 40% non- Bt corn refuge); or planted fewer than 2/3 of the Bt corn fields are planted within 1/2 mile of a non- Bt 

corn refuge.

b. Registrant results for first time on-farm –growers planting CRW protected PIPs

2010 Data:

Of the 58 growers planting corn rootworm protected Bt corn and having received a first-time on-farm 

assessment in 2010, 30.9% were non-compliant with refuge requirements, Of all the growers assessed, 12.1% 

had significant deviations (see Table 6). On-farm assessments were randomly conducted across a range of farm 

sizes with approximately 33% of growers categorized as “small growers” with less than 250 acres of corn. As 

with previous years, the data suggest that farm size should not be a selection criterion when trying to identify 

non-compliant growers. Growers significantly out of compliance in 2010 will be reassessed during the 2011 

growing season.
- 14 -

Table 6.Cumulative Results for the On-Farm Coleopteran-Protected Bt Corn Assessment (2006-2010 data)

Issue addressed 2006 2007 2008 2009 2010

Growers assessed 395 247 134 110 58

Refuge distance 

deviations 131 N/A N/A N/A N/A

Refuge size deviations 7 N/A N/A N/A N/A

Significant 

deviations2

11

(2.8%)

16

(6.5%)

12

(9.0)

29

(26.4%)

7

(12.1%)

Insignificant 

deviations

10 

(4.0%)

8 

(3.2%) 7 (5.2%) 5 (4.5%) 3

(2.5%)

Compliant growers 374 

(94.7%)

223 

(90.3%)

115 

(85.8%)

76 

(69.1%)

51

(84.5%)

Non-compliant 

growers

21

(5.3%)

24

(9.7%)

19

(14.2%)

34

(30.9%)

9

(15.5%)

1 Some growers had compliance deviations other than refuge size or distance; thus, the total of refuge distance and size deviations does not 

equal the number of non-compliant growers. 2 Significant deviations are defined as: Bt corn grower who planted less than 15% non- Bt corn refuge (except in certain cotton growing areas in 

which case it would be less than 40% non- Bt corn refuge); or planted fewer than 2/3 of the Bt corn fields are planted within 1⁄2 mile of a nonBt corn refuge.

c. Registrant results for first time on-farm –growers planting stacked PIPs

2010 Data:

Of the 2272 growers planting corn borer protected Bt corn and having received a first-time on-farm assessment 

in 2010, 16.2% were non-compliant with refuge requirements. Of all the growers assessed, 8.8% had significant 

deviations (see Table 7). On-farm assessments were randomly conducted across a range of farm sizes with 

approximately 33% of growers categorized as “small growers” with less than 250 acres of corn. As with 

previous years, the data suggest that farm size should not be a selection criterion when trying to identify noncompliant growers. Farmers that were significantly out of compliance in 2010 will be reassessed during the 

2011 growing season.
- 15 -

Table 7. Cumulative Results of the First Time On-Farm Stacked Bt Corn Assessment1 (Data for 2006-2010)

Issue addressed 2006 2007 2008 2009 2010

Growers assessed 600 1069 1799 1789 2272

Refuge distance 

deviations 512 N/A N/A N/A N/A

Refuge size deviations 8 N/A N/A N/A N/A

Significant deviations 453

(7.5%)

77

(7.2%) 864 193(10.8%)

200

(8.8%)

Insignificant 

deviations

16 33

(3.1%) 364 106(5.9%)

168

(7.4%)

Compliant growers 539

(89.8%)

959

(89.7%)

1546

(85.9%)

1490

(83.3%)

1904

(83.8%)

Non-compliant 

growers

61

(10.2%)

110

(10.3%)

253

(14.1%)

299

(16.7%)

368

(16.2%)

1

Table adapted from page 12 of MRID 470444-01 2 Some growers had compliance deviations other than refuge size or distance; thus, the total of refuge distance and size deviations does not equal 

the number of non-compliant growers. 3 Significant deviations are defined as: A Bt corn grower who planted less than 15% non- Bt corn refuge (except in certain cotton growing 

areas in which case it would be less than 40% non- Bt corn refuge); or planted fewer than 2/3 of the Bt corn fields are planted within 1⁄2 mile 

of a non- Bt corn refuge. 4

The numbers of deviations to not add up to the 253 non-compliant cases reported.

5. On-farm Reassessment Program

In 2009, a total of 510 growers were found to be out of compliance of which 339 cases fell into the ‘significant 

violations’ category. All compliance violations were responded to in accordance with the Phased Compliance 

Approach, including a reassessment of growers in 2010 with significant violations. Of those growers who were 

reassessed in 2010, a small number did not farm or plant Bt any longer, and one grower was revoked access to 

the technology based on continued significant non-compliance.

Table 8. 2010 Reassessment data of growers significantly out of compliance in 2009

Product Type 2009 Noncompliance cases2009 significant noncompliance casesNumber of revoked 

licenses in 2010

ECB corn PIPs 177 117 1a

CRW corn PIPs 34 29 0

Stacked corn PIPs 299 193 1 a

TOTAL 510 339 2

Extracted from ABSTC 2010 CAP report

a One grower was found to be significantly out of compliance two years in a row for two unique product types
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BPPD REVIEW OF ON-FARM ASSESSMENT RESULTS (2009)

ABSTC states that “the on farm assessment program is not a statistical tool for measuring the level of adherence 

to the IRM requirements”, and that rather, “this program helps identify obstacles that hinder grower 

implementation of IRM requirements”. BPPD notes that a comparison between year-to-year on-farm survey 

results then should be made with caution because, among other things, the growers were not randomly selected 

from companies’ customer lists. BPPD is aware that companies do not share their clientele list with each other 

and that names and locations of non-compliant growers are confidential and anonymous. Yet, BPPD proposes 

that ABSTC compile and maintain, through a neutral third party, maps showing the distribution of on-farm noncompliance pooled across registrants so that it is clear to EPA where these non-compliant regions are located. It 

may then be possible for ABSTC to focus compliance efforts in these regions with increased educational 

outreach or other appropriate new measures.

For growers having planted ECB protected PIPs, adherence to refuge requirements was high (86.6%), and 

significant violations were lower (8.4%) than reported for the 2009 season (10.8%).

For growers planting CRW protected PIPs, adherence to refuge requirements was higher (84.5%) than for the 

2009 growing season (69.1%), and significant violations were 50% lower than reported for 2009. The sample 

size for first time on-farm assessments keeps decreasing each year (see Table 6). At some point, the results will 

not be very informative any longer for grower’s planting CRW protected PIPs if the sample size continues to 

shrink. BPPD recommends that individual companies increase their sample size of CRW on-farm assessments 

for 2011.

For growers planting stacked PIPs, adherence to refuge requirements was similar (83.8%) to what was reported 

for the 2009 growing season (83.3%). Significant violations were lower in 2010 (8.8%) compared to 2009 

(10.8%).

ABSTC stated that one grower had his license revoked in 2010; however, their data (Table 8) showed that two 

growers had some significant violations with compliance requirements (one grower for ECB PIPs and another

for stacked products - unless the same grower planted both a single and stacked product and committed a 

violation for both types of PIPs in 2010) and were denied access to the technology for 2011.

6. TIPS AND COMPLAINTS

2010 Data:

In 2010, the registrants received two ‘tips and complaints’. Legitimate tips and complaints were managed in 

accordance with the CAP requirements. Growers out of compliance who were identified as a result of a 

legitimate tip or complaint received an on-farm IRM visit, and growers found to be out of compliance during 

this visit were responded to in a manner consistent with the Phased Compliance Approach.
- 17 -

Table 9. Anonymous Tips and Complaints about Non-Compliance with IRM requirements

Year Number of Tips and 

Complaints

2010 2

2009 4

2008 5

2007 14

2006 3

2005 5

2004 0

2003 0

7. SUMMARY OF ABSTC’S MAIN CONCLUSIONS

The compliance assurance programs continue to be effective. In 2010, the majority of growers surveyed planted 

the required size of refuge within the required distance for all their Bt corn fields on their farms. Furthermore, 

the survey indicates that the majority of Bt fields have a refuge associated with them (82% to 94%). These 

findings are broadly similar to those found in surveys conducted over the last three years. 

ABSTC stated that compliance was similar between growers of eastern and western corn growing regions, but 

that southern corn growers showed lower levels of adherence. They attributed some of this non-compliance in 

cotton growing regions to the fact that a larger refuge size was required (50%) and that grower awareness of 

IRM requirements was lower than in the north. ABSTC reported that approximately 10% of the total US corn 

was grown in the south in 2009, and that, therefore, the effect on overall selection for resistance was likely 

small.

8. BPPD REVIEW OF OVERALL CAP

ABSTC concluded that the majority of growers who planted single trait ECB PIP products were compliant with 

the refuge requirements in 2010 when national average results from the on-line survey were considered (76% 

for refuge size; 87% for refuge distance) . Compliance among growers planting CRW protected PIPs was low

and unchanged from the reported 2009 results. Compliance percentages for stacked PIP products have now 

reached an all time low (69% for refuge size; 63% for refuge distance), yet based on the standard error 

provided, these differences were not statistically significant from the 2009 results. Nonetheless, BPPD is 

concerned about these compliance numbers, especially considering that surveyed growers could not 

demonstrated IRM knowledge in the online survey. On an unaided basis, only 61% of the growers could recall 

the correct refuge size and only 56% recalled the correct refuge distance for the ECB and CRW portion of the 

stacked PIPs. ABSTC has not been able to demonstrate that their educational efforts increase grower awareness 

with refuge requirements for stacked PIPs.. It is recommended that ABSTC meet with BPPD to discuss future 

approaches in increasing IRM knowledge and compliance among growers planting stacked PIPs.

The online survey measuring 2010 grower compliance with refuge requirements for stacked PIPs demonstrated 

(as in 2009) that southern corn growers (in cotton growing regions) were up to 2.2 more likely to get out of 
- 18 -

compliance than their northern counterparts. Possible explanations for lower levels of compliance in the south 

could include confusion with different requirements between various PIP products or simply blatant disregard 

of refuge requirements by growers who plant both Bt corn and Bt cotton. ABSTC stated in their 2009 CAP 

report that these regional results provided them with the opportunity to intensify future educational efforts in the 

southern corn growing regions. BPPD notes that if higher non-compliance among southern corn growers 

reflects a willingness to violate refuge requirements rather than a lack of knowledge, then increased educational 

efforts may not be fruitful. Other methods may be needed to bring these growers back into compliance. 

Furthermore, BPPD disagrees with ABSTC’s statement that the risk of resistance evolution may be lower in the 

south despite the greater non-compliance because only 10% of the corn production occurs in that region (cited 

from 2009 USDA data). Although higher Bt adoption in conjunction with non-compliance could be a strong 

driver for resistance evolution, it cannot be discounted that consistent local non-compliance with refuge 

requirements in the south increases the risk of resistance evolution in such areas despite lower Bt corn adoption. 

Of greater importance for local non-compliance (resistance will likely be a local phenomenon initially) is the 

amount of refuge available at that scale, and the amount of immigration of refuge insects from other corn 

growing areas. Additional data or information would be needed to evaluate ABSTC’s claim of low potential 

risk of resistance evolution in the south (with less compliance and adoption of Bt corn).

In contrast to the online survey program, ABSTC states that “the on farm assessment program is not a statistical 

tool for measuring the level of adherence to the IRM requirements”, and that rather, “this program helps 

identify obstacles that hinder grower implementation of IRM requirements”. BPPD notes that a comparison 

between year-to-year on-farm survey results then should be made with caution because, among other things, the 

growers were not randomly selected from companies’ customer lists. BPPD is aware that companies do not 

share their clientele list with each other and names and locations of non-compliant growers are kept confidential 

and anonymous. Yet, BPPD recommends that ABSTC compile and maintain, through a neutral third party,

maps showing the distribution of on-farm non-compliance pooled across registrants so that it is clear to the EPA

where regions of high non-compliance are located. It may then be possible for ABSTC to focus compliance 

efforts in these regions with increased educational outreach by the registrants or other appropriate new 

measures.

BPPD recommends that individual companies increase the sample size for CRW first-time assessment. It 

appears that a sample size of 50-60 farmers is likely insufficient to acquire a good understanding of confirmed 

on-farm compliance with IRM requirements.

REFERENCES

Bookout J, D Guyer, MSmith, and N Storer. 2011. 2010 insect resistance management compliance assurance 

program report for corn borer-protected Bt corn, corn rootworm-protected Bt corn, and corn borer/corn 

rootworm-protected stacked Bt corn.