FOR INFORMATION AND ACTION

DA-2022-27 

August 17, 2022 

Subject: APHIS Amends Karnal Bunt (Tilletia indica) Regulated Areas in La Paz, Maricopa, and Pinal 

Counties in Arizona 

To: State and Territory Agricultural Regulatory Officials

Effective immediately, the Animal and Plant Health Inspection Service (APHIS) is amending the Karnal

bunt regulated areas in La Paz, Maricopa, and Pinal Counties in Arizona. 

APHIS is removing seven fields (199 acres) from the list of regulated areas. One field has been regulated for 

twenty-one years, four fields for twenty-three years, and two fields for twenty-four years. Thirty-seven (37) 

acres in La Paz County are on the Colorado River Indian Reservation of the Colorado River Indian Tribes; 

32 acres are non-tribal land in Maricopa County; and 130 acres in Pinal County are on the Gila River Indian 

Reservation of the Gila River Indian Community. 

In 1999, APHIS regulated four fields in Pinal County, not because they were positive for Karnal bunt, but 

because they were planted with non-fungicide treated wheat seed. On February 5, 2003, APHIS published a 

final rule removing the requirement that host seed be fungicide-treated before planting. Therefore, APHIS is

removing these four fields from regulation because the fields never tested positive for Karnal bunt and seed 

treatment is no longer a requirement in 7 C.F.R. § 301.89. 

A recent APHIS analysis concluded that the likelihood of any teliospores of T. indica remaining viable in 

three additional fields (one each in La Paz, Maricopa, and Pinal counties) is negligible because: they had a 

low initial population of T. indica when first regulated, a sustained host-free period (more than twenty years) 

after their first planting, and a record of both tillage and irrigation that enhances population reduction through 

suicidal germination of teliospores in the soil. Accordingly, APHIS is deregulating these seven fields (199 

acres). However, other portions of La Paz, Maricopa, and Pinal Counties remain regulated. 

APHIS regulates Karnal bunt because many trading partners require that U.S. wheat be certified as grown in 

areas free of this plant disease. APHIS will follow this emergency action by publishing a notice in the 

Federal Register. 

More information on Karnal bunt is available at the following website: 

http://www.aphis.usda.gov/plant-health/kb

For additional information about the Karnal bunt program, please call National Policy Manager, Lynn EvansGoldner, at (301) 851-2286. 

Dr. Mark L Davidson 

Deputy Administrator 

Plant Protection and Quarantine 

Attachment: Federal Order
United States Department of Agriculture

Animal and Plant Health Inspection Service 

Plant Protection and Quarantine

Federal Order

Domestic Quarantine for

Karnal Bunt (Tilletia indica)

DA-2022-27 

August 17, 2022 

This Federal Order amends the Karnal bunt regulated areas in La Paz, Maricopa, and Pinal Counties in 

Arizona and reduces the overall regulated area in Arizona. 

This Federal Order is issued pursuant to the authority provided by the Plant Protection Act of June 20, 

2000, Section 412(a), 7 U.S.C. 7712(a). The Act authorizes the Secretary of Agriculture to prohibit or 

restrict the movement in interstate commerce of any plant, plant part, or article if the Secretary

determines the prohibition or restriction is necessary to prevent the dissemination of a plant pest within 

the United States. The regulatory authority provided by 7 U.S.C. 7754 allows the Secretary to issue 

orders to carry out this provision of the Plant Protection Act. This Federal Order is likewise issued

pursuant to the regulations promulgated under the Plant Protection Act found at 7 CFR 301.89 et seq. 

Section 7 CFR § 301.89-3(b) allows the designation of less than an entire state as a Karnal bunt 

regulated area only when the Administrator of the Animal and Plant Health Inspection Service (APHIS) 

has determined, as in this case, that the designation is adequate to prevent the interstate spread of Karnal

bunt. In addition, 7 CFR § 301.89-3(b)(1)(i) requires that in order for less than an entire state to be 

designated that the Administrator find that the state is enforcing an intrastate Karnal bunt quarantine that 

is equivalent to federal Karnal bunt regulations. The Arizona State Plant Regulatory Official has

confirmed the establishment of an intrastate quarantine area for Karnal bunt that mirrors the federal 

regulatory requirements as specified in 7 CFR § 301.89. 

This Federal Order updates and replaces the regulated areas in Arizona designated in the Code of 

Federal Regulations located at 7 CFR § 301.89-3(g), and replaces Federal Order (DA-2011-69) issued 

December 6, 2011, Federal Order (DA-2013-51) issued November 22, 2013, Federal Order (DA-2016-

57) issued October 3, 2016, Federal Order (DA-2017-08) issued April 11, 2017, Federal Order (DA2018-09) issued April 5, 2018, Federal Order (DA-2019-08) issued May 8, 2019, Federal Order (DA2020-04) issued February 4, 2020, Federal Order (DA-2021-27) issued October 22, 2021, and Federal

Order (DA-2022-04) issued February 2, 2022. This Federal Order does not negate the removal of wheat,

durum wheat, and triticale harvested for silage from the list of regulated articles at 7 CFR § 301.89-2 as

presented in Federal Order (DA-2017-08).

APHIS is reducing the Karnal bunt regulated area in La Paz, Maricopa, and Pinal Counties in Arizona

by removing seven fields (199 acres) from the list of regulated areas. One field has been regulated for 

twenty-one years; four have been regulated for twenty-three years; and two have been regulated for 
twenty-four years. One field (37 acres) in La Paz County is on the Colorado River Indian Reservation of 

the Colorado River Indian Tribes; one field (32 acres) in Maricopa County is not on tribal land; and five 

fields (130 acres) in Pinal County are on the Gila River Indian Reservation of the Gila River Indian 

Community.

In 1999, APHIS regulated four fields (73 acres) in Pinal County on the Gila River Indian Reservation, 

not because they were positive for Karnal bunt, but because they were planted with non-fungicide 

treated wheat seed. On February 5, 2003, APHIS published a final rule (Docket No. 01–118–2) that 

removed the requirement that T. indica hosts, wheat and triticale seed, be treated with a fungicide before 

being planted within a Karnal bunt regulated area. For twenty-two years, two of these fields were 

abandoned and left fallow, and two were planted continuously to non-host perennial crops. In addition, 

each field was also tilled and irrigated at least once. These factors would inhibit the ability of T. indica

teliospores to survive, even if they were initially present. Therefore, APHIS is removing these four fields 

(73 acres) from regulation because the fields never tested positive for Karnal bunt; a fungicide seed 

treatment is no longer a requirement in 7 C.F.R. § 301.89; and the fields have not been planted to host 

crops for decades.

Based on the findings of an APHIS analysis, APHIS is removing an additional three fields (126 acres)

from the list of regulated areas. The analysis concluded that the likelihood of any teliospores of T. indica

remaining viable in these fields is negligible. The initial T. indica populations in these fields was 

predicted to be extremely low (0.002 to 0.006 percent) based on the bunted kernel counts from a 4-

pound wheat seed sample, which contains approximately 45,400 seeds (7 CFR §201.46). The analysis 

found that a sustained period with no host crops and a record of both tillage and irrigation would further 

reduce the population of T. indica. The likelihood of any teliospores remaining viable in these fields,

which were not planted with host crops for more than 20 years, is negligible. Teliospores decline over 

time through disintegration in the soil; and tillage and irrigation enhances population reduction through 

suicidal germination. Therefore, APHIS is removing three fields (126 acres) from regulation.

Accordingly, there are no more restrictions on the interstate movement of Karnal bunt regulated articles 

from these seven fields (199 acres). However, other portions of La Paz, Maricopa, and Pinal Counties 

remain regulated.

Regulated areas § 301.89-3 (g).

The Table below lists the seven individual fields in Arizona that are deregulated for Karnal bunt. 
Individual Fields in Arizona Deregulated for Karnal bunt (Tilletia indica)

Field Acres County Tribe

LP1 37 La Paz Colorado River Indian Tribes of the Colorado River Indian Reservation

M1 32 Maricopa None

P1 57 Pinal Gila River Indian Community of the Gila River Indian Reservation

P2 36 Pinal Gila River Indian Community of the Gila River Indian Reservation

P3 18 Pinal Gila River Indian Community of the Gila River Indian Reservation

P4 10 Pinal Gila River Indian Community of the Gila River Indian Reservation

P5 9 Pinal Gila River Indian Community of the Gila River Indian Reservation

Arizona – additional regulated portions of the State:

La Paz County. Beginning at the northeast corner of sec. 36, T. 8 N., R. 21 W.; then south to the 

southeast corner of sec. 1, T. 7 N., R. 21 W.; then east to the northeast corner of sec. 7, T. 7 N., R. 20 

W.; then south to the southeast corner of sec. 19, T. 7 N., R. 20 W.; then west to the southwest corner of 

sec. 19, T. 7 N., R. 20 W.; then south to the southeast corner of sec. 36, T. 7 N., R. 21 W.; then west to 

the southwest corner of sec. 32, T. 7 N., R. 21 W.; then north to the northwest corner of sec. 32, T. 7 N., 

R. 21 W.; then west to the southwest corner of sec. 30, T. 7 N., R. 21 W.; then north from that point to 

the Colorado River; then northeast along the Colorado River to the northern boundary of sec. 32 T. 8 N., 

R. 21 W.; then east to the point of beginning.

Maricopa County. (1) Beginning at the southeast corner of sec. 21, T. 1 N., R. 1 E.; then west to the 

southwest corner of sec. 24, T. 1 N., R. 1 W.; then north to the southeast corner of sec. 14, T. 1 N., R. 1 

W.; then west to the southwest corner of sec. 14, T. 1 N., R. 1 W.; then north to the northwest corner of 

sec.35, T.2 N., R.1 W.; then east to the northeast corner of sec. 35, T.2 N., R.1 W.; then north to the 

northwest corner of sec. 25, T. 2 N., R.1 W.; then east to the southwest corner of sec. 20, T.2 N., R. 1 E.; 

then north to the northwest corner of sec. 20, T. 2 N., R.1 E.; then east to the northeast corner of sec. 21, 

T. 2 N., R.1 E.; then south to the southeast corner of sec. 21, T.2 N. R. 1 E.; then east to the northeast 

corner of sec. 27, T.2 N., R.1 E.; then south to the southeast corner of sec. 27, T.2 N. R. 1 E.; then east 

to the northeast corner of sec. 35, T. 2 N., R. 1 E.; then south to the southeast corner of sec. 14, T. 1 N., 

R. 1 E.; then west to the southwest corner of sec. 15, T. 1 N., R. 1 E.; then south to the point of 

beginning.

(2) Beginning at the southeast corner of sec. 4, T. 1 S., R. 1 W.; then west to the northeast corner of sec.

7, T. 1 S., R. 1 W.; then south to the southeast corner of sec. 7, T.1 S., R. 1 W.; then west to the 

southwest corner of sec. 9, T. 1 S., R. 2 W.; then north to the northwest corner of sec. 9, T. 1 S., R. 2 W.; 

then west to the southwest corner of sec. 5, T.1 S., R.2 W.; then north to the northwest corner of sec. 5, 

T.1 S., R. 2 W.; then east to the southwest corner of sec. 33, T. 1 N., R. 2 W.; then north to the northwest 

corner of sec. 21, T.1 N., R.2 W.; then east to the northeast corner of sec. 22, T.1 N, R.2 W.; then north 

to the northwest corner of sec. 14, T.1 N., R.2 W.; then east to the northeast corner of sec. 14, T.1 N., 

R.2 W.; then south to the southeast corner of sec. 14, T.1 N., R.2 W.; then east to the northeast corner of 

sec. 20, T.1 N., R.1 W.; then south to the southeast corner of sec. 20, T.1 N., R.1 W.; then east to the 

northeast corner of sec. 28, T.1 N., R.1 W.; then south to the point of beginning.

(3) Beginning at the southeast corner of sec. 35, T. 2 N., R. 5 E.; then west to the northeast corner of sec. 

4, T. 1 N., R. 5 E.; then south to the southeast corner of sec. 4, T. 1 N., R. 5 E.; then west to the 
southwest corner of sec. 4, T. 1 N., R. 5 E.; then south to the southeast corner of sec. 17, T. 1 N., R. 5 E.; 

then west to the southwest corner of sec. 17, T. 1 N., R. 5 E.; then north to the northwest corner of sec. 

17, T. 1 N., R. 5 E.; then west to the southwest corner of sec. 12, T. 1 N., R. 4 E.; then north to the 

northwest corner of sec. 12, T. 1 N., R. 4 E.; then east to northeast corner of sec. 12, T. 1 N., R. 4 E.; 

then north to the northwest corner of sec. 18, T. 2 N., R. 5 E.; then east to the northeast corner of sec.14, 

T. 2 N., R. 5 E.; then south to the point of beginning.

(4) Beginning at the southeast corner of sec. 32, T. 2 N., R. 1 W.; then west to the southwest corner of 

sec. 34, T. 2 N., R. 2 W.; then north to the southeast corner of sec. 21, T. 2 N., R. 2 W.; then west to the 

southwest corner of sec. 21, T. 2 N., R. 2 W.; then north to the northwest corner of sec. 21, T. 2 N., R. 2 

W.; then east to the northeast corner of sec. 21, T. 2 N., R. 2 W.; then north to the northwest corner of 

sec. 34, T. 3 N., R. 2 W.; then east to the northeast corner of sec. 32, T. 3 N., R. 1 W.; then south to the 

point of beginning.

(5) Beginning at the southeast corner of sec. 27, T. 1 S., R. 4 W.; then west to the southwest corner of 

sec. 27, T. 1 S., R. 5 W.; then north to the northwest corner of sec. 22, T. 1 S., R. 5 W.; then east to the 

northeast corner of sec. 22, T. 1 S., R. 5 W.; then north to the northwest corner of sec. 26, T. 1 N., R. 5 

W.; then east to the northeast corner of sec. 29, T. 1 N., R. 4 W.; then south to the southeast corner of 

sec. 29, T.1 N., R. 4 W.; then east to the northeast corner of sec. 33, T. 1 N., R. 4 W.; then south to the 

southeast corner of sec. 33, T. 1 N, R. 4 W.; then east to the northeast corner of sec. 3, T. 1 S., R. 4 W.; 

then south to the point of beginning.

Pinal County: (1) Beginning at the southeast corner of sec. 4, T. 6 S., R. 4 E.; then west to the southwest 

corner of sec. 4, T. 6 S., R. 4 E.; then south to the southeast corner of sec. 17, T. 6 S., R. 4 E.; then west 

to the southwest corner of sec. 16, T. 6 S., R. 3 E.; then north to the southeast corner of sec. 5, T. 6 S., R. 

3 E.; then west to the southwest corner of sec. 6, T. 6 S., R. 3 E.; then north to the southeast corner of 

sec. 31, T. 5 S., R. 3 E.; then west to the southwest corner of sec. 31, T. 5 S., R. 3 E.; then north to the 

southeast corner of sec. 24, T. 5 S., R. 2 E.; then west to the southwest corner of sec. 24, T. 5 S., R. 2 E.; 

then north to the northwest corner of sec. 1, T. 5 S., R. 2 E.; then east to the southwest corner of sec. 31, 

T. 4 S., R. 3 E.; then north to the northwest corner of sec. 30, T. 4 S., R. 3E.; then east to the southwest 

corner of sec. 20, T. 4 S., R. 3E.; then north to the northwest corner of sec. 20, T. 4 S., R. 3E.; then east 

to the northeast corner of sec. 19, T. 4 S., R. 4 E.; then south to the northwest corner of sec. 32, T. 4 S.,

R. 4 E.; then east to the northeast corner of sec. 32, T. 4 S., R. 4 E.; then south to the northwest corner 

of sec. 21, , T. 5 S., R. 4 E.; then east to the northeast corner of sec. 21, , T. 5 S., R. 4 E.; then south to 

the northwest corner of sec. 4, T. 6 S., R. 4 E.; then east to the northeast corner of sec. 4, T. 6 S., R. 4 

E.; then south to the point of beginning.

(2) Beginning at the intersection of the Maricopa/Pinal County line and the northeast corner of sec. 4, T. 

3 S., R. 6 E.; then south to the southeast corner of sec. 28, T. 3 S., R. 6 E.; then west to the southwest 

corner of sec. 28, T. 3 S., R. 6 E.; then south to the southeast corner of sec. 32, T. 3 S., R. 6 E.; then west 

to the southwest corner of sec. 35, T. 3 S., R. 5 E.; then north to the northwest corner of sec. 26, T. 3 S., 

R. 5 E.; then west to the southwest corner of sec. 22, T. 3 S., R. 5 E.; then north to the northwest corner 

of sec. 3, T. 3 S., R. 5 E.; then east along the Maricopa/Pinal County line to the point of beginning.

APHIS appreciates the cooperative relationship with the state regulatory officials, Colorado River Indian 

Tribes of the Colorado River Indian Reservation, Ak-Chin Indian Community, Gila River Indian 
Community of the Gila River Indian Reservation, the Salt River Pima Maricopa Indian Community, and 

the wheat industry, in our effort to prevent the spread of Karnal bunt.

For more information on the Karnal bunt program, please call National Policy Manager, Lynn EvansGoldner, at (301) 851-2286.