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 IRM knowledge in the online survey. On an 

unaided basis, only 33% of the growers could recall the correct refuge size and only 22% 

recalled the correct refuge distance for the ECB and CRW portion of the stacked PIPs. This 

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. ABSTC does 

not appear to be achieving its educational goals among growers planting stacked PIP 

products. Educational efforts have also been unsuccessful at increasing grower education 

with respect to CRW IRM requirements. 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 

- 2 - 
needed to evaluate ABSTC’s claim of low potential risk of resistance evolution in the south 

(with less compliance and adoption of Bt corn). 

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 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 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). 

- 3 - 
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 selfappointed 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 noncompliant growers, third-party grower survey (via telephone and, since 2007, only on-line), onfarm 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%.

- 5 - 
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 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% 

- 6 - 
Unaided Recall of IRM Requirements

Refuge size (weighted average 

across all four regions surveyed) 

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

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%. 

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 the appropriate distance. 

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 Rootworm-Protected 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% 

 1YieldGard RW and YieldGard Plus corn growers 2YieldGard RW, YieldGard Plus, Herculex RW, and Herculex XTRA corn growers. 3Weighted 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 refuge 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, 66% 

and 59% correctly identified the refuge size for ECB and CRW, respectively. On an unaided 

basis, 83% and 32% 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 non-compliance 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, 

- 9 - 
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 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 noncompliance 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 

0

20

40

60

80

100

120

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

% Compliance

Planting season

Compliance with refuge requirementsfor ECB protected

corn PIPs

refuge size

refuge distance

- 10 - 
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 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 

0

20

40

60

80

100

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

% Compliance

Planting season

Compliance with refuge requirementsfor CRW

protected corn PIPs

refuge size

refuge distance

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 69% in 2010; adherence to refuge distance was 

67% in 2009 and declined to 63%. Compliance in the western regions of the Corn Belt remained 

- 11 - 
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. 

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

0

20

40

60

80

100

'06 '07 '08 '09 '10

% Compliance

Planting season

Compliance with refuge requirementsfor stacked corn

PIPs

refuge size

refuge distance

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 

- 12 - 
4. ON-FARM ASSESSMENT PROGRAM 

The on-farm assessment portion of the Compliance Assurance Program identifies individual noncompliant 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 on-farm 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 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 the PCA. 

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 onfarm assessment in 2010, 86.6% were fully compliant with refuge requirements (see Table 5). Of 

the 13.4% non-compliant growers, 8.4% had significant deviations. On-farm assessments were 

conducted across a range of farm sizes with approximately 33% of growers categorized as “small 

- 13 - 
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. 

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: 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 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 onfarm assessment in 2010, 84.5% were fully compliant with refuge requirements. Of the 30.9% 

non-compliant growers, 15.5% had significant deviations. 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 

(13.0%) 

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: 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 2 mile of a non- Bt 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 onfarm assessment in 2010, 83.8% were fully compliant with refuge requirements. Of the 16.2% 

non-compliant growers, 8.8% had significant deviations. 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. 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 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 cases 2009 significant noncompliance cases Number 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 

- 16 - 
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 non-compliance 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 33% of the growers could recall 

the correct refuge size and only 22% recalled the correct refuge distance for the ECB and CRW 

portion of the stacked PIPs. It appears that ABSTC is not achieving its educational goals among 

growers planting stacked PIP products. It is recommended that ABSTC meet with BPPD to 

discuss future approaches in increasing IRM knowledge and compliance among growers planting 

stacked PIPs. 

- 18 - 
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 noncompliance 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 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 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. 

 

- 19 - 
- 20 - 

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.