FOR INFORMATION AND ACTION

DA-2024-05 

February 14, 2024 

Subject: APHIS Reduces Karnal Bunt (Tilletia indica) Regulated Areas in Maricopa and Pinal 

 Counties in Arizona 

To: State, Tribal, and Territory Agricultural Regulatory Officials

 

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

Karnal bunt regulated areas in Maricopa and Pinal Counties, Arizona. This is following a review 

of the results of the 2023 survey of Karnal bunt-regulated areas in Arizona. 

Specifically, APHIS is removing three fields in Pinal County from the list of regulated areas 

because these fields meet the five-year cumulative tillage requirement included in the criteria for 

deregulation listed in 7 Code of Federal Regulations (CFR) § 301.89-3(e)(2). 

In addition, APHIS is reducing the three-mile buffer area around positive fields in Maricopa and 

Pinal Counties to 0.2 miles based on an analysis APHIS completed on January 26, 2015. The 

analysis determined that a reduced buffer distance of 0.2 miles will provide the desired level of 

phytosanitary protection from Karnal bunt’s causal agent, Tilletia indica. APHIS did not 

implement the reduced buffer in 2015 because it was not operationally and administratively 

feasible to do so based on the number of fields regulated at the time. With the significant 

decrease in the number of infested fields since 2015, APHIS and the Arizona Department of 

Agriculture (AZDA) are now instituting the 0.2-mile buffer. This action to reduce the buffer is 

consistent with the regulations in 7 CFR 301.89-3(c). The buffer reduction will free multiple 

growers from quarantine requirements and relieve APHIS of continued monitoring in buffer 

fields that never had a positive Karnal bunt detection, without compromising safeguards against 

the spread of T. indica. 

Due to the above changes, APHIS is removing a total of 36,982 field acres (835 fields) in 

Arizona from Karnal bunt regulation: 15,361 field acres (379 fields) in Maricopa County and 

21,621 field acres (456 fields) in Pinal County, including 11,717 field acres (228 fields) on AkChin Indian Community tribal land and 6,830 field acres (162 fields) on Salt River PimaMaricopa Indian Community tribal lands. Accordingly, there are no more restrictions on the 

interstate movement of Karnal bunt-regulated articles from these areas; however, other portions 

of Maricopa and Pinal Counties remain regulated. AZDA has established a parallel state 

quarantine. 

Karnal bunt is a fungal pest that affects wheat quality. APHIS regulates this plant disease because 

many trading partners require that U.S. wheat be certified as grown in areas free of Karnal bunt. 

We appreciate the cooperative relationship with the Ak-Chin Indian Community, the Salt River 

Pima-Maricopa Indian Community, the wheat industry and AZDA in the effort to limit the spread 

of Karnal bunt. APHIS will follow this action by publishing a notice in the Federal Register. 
More information about the Karnal Bunt Program and federal Karnal bunt regulations is 

available at the following website: APHIS Karnal Bunt webpage. 

For additional information about the Karnal Bunt program, please contact National Policy 

Manager, Lynn Evans-Goldner, at lynn.evans-goldner@usda.gov or (301) 851-2286. 

 

Dr. Mark L Davidson 

Deputy Administrator 

Plant Protection and Quarantine 

Attachment: Federal Order
FEDERAL ORDER

Domestic Quarantine for

Karnal Bunt (Tilletia indica) 

DA-2024-05 

February 14, 2024 

This Federal Order reduces the Karnal bunt-regulated areas in Maricopa and Pinal Counties 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 also issued pursuant to the regulations promulgated under the Plant Protection 

Act found at 7 Code of Federal Regulations (CFR) § 301.89 et seq.

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

total regulated area in Arizona by 36,982 field acres (835 fields): 15,361 field acres (379 fields) 

in Maricopa County and 21,621 field acres (456 fields) in Pinal County, including 11,717 field 

acres (228 fields) on Ak-Chin Indian Community tribal land and 6,830 field acres (162 fields) on 

Salt River Pima-Maricopa Indian Community tribal lands. Accordingly, there are no more 

restrictions on the interstate movement of Karnal bunt regulated articles from these areas; 

however, other portions of Maricopa and Pinal Counties remain regulated. 

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 APHIS Administrator has determined, as in this case, that the 

designation of less than an entire state as a quarantined-Karnal bunt area is adequate is to prevent 

the intrastate spread of Karnal bunt. In addition, 7 CFR § 301.89-3(b)(1)(i) requires that the state 

enforce an intrastate Karnal bunt quarantine equivalent to the federal regulations. The state plant 

regulatory official for Arizona confirmed the establishment of an intrastate quarantine for the 

regulated area that mirrors the Federal Regulatory requirements as specified in CFR § 301.89 et 

seq. 

Following a review of the results of the 2023 survey of Karnal bunt-regulated areas in Arizona, 

APHIS is reducing the regulated area. Specifically, APHIS is removing three fields in Pinal 

County from the list of regulated areas because these fields meet APHIS’ requirements and

criteria for deregulation. 7 CFR § 301.89-3(e) provides for the release from regulation of fields 

previously infected with Karnal bunt if the field is tilled at least once per year for a total of 5 

years (the years need not be consecutive). After tilling, the field may be planted with a crop or 

left fallow. If the field is planted with a host crop, the crop must test negative, through the 

absence of bunted kernels, for Karnal bunt. 
In addition, on January 26, 2015, APHIS completed an analysis that determined that a reduced 

buffer distance of 0.2 miles will provide the desired level of phytosanitary protection from 

Karnal bunt’s causal agent, Tilletia indica. Accordingly, APHIS is reducing the three-mile buffer 

area around positive fields in Maricopa and Pinal Counties to 0.2 miles. APHIS did not 

implement the reduced buffer in 2015 because it was not operationally and administratively 

feasible to do so because of the number of fields regulated at the time. With the significant 

decrease in the number of infested fields since 2015, APHIS and the Arizona Department of 

Agriculture (AZDA) are now instituting the 0.2-mile buffer. The buffer reduction frees multiple 

growers from quarantine requirements and relieves APHIS of continued monitoring in buffer 

fields that never had a positive Karnal bunt detection, without compromising safeguards against 

the spread of T. indica. This action to reduce the buffer is consistent with the regulations at 7 

CFR 301.89-3(c) that provide for the temporary designation of regulated areas and the 

termination of the temporary designation provided that the owner or person in possession of, or, 

in the case of publicly owned land, the person responsible for the management of, an area for 

which the designation is terminated is given written notice of the termination by APHIS. 

Regulated areas § 301.89-3(a): 

Arizona – regulated portions of the State: 

Maricopa County: 

(1) Scottsdale: Sections 28, 29, 32 and 33 of Township 2 North and Range 5 East. 

(2) Palo Verde: Sections 7, and 17 through 20 of Township 1 South and Range 4 West; and 

Sections 12 and 13 of Township 1 South and Range 5 West. 

Pinal County: 

(1) Maricopa: Section 34 of Township 4 South and Range 3 East; Sections 3, 11, and 14 of 

Township 5 South and Range 3 East. 

In accordance with 7 CFR § 301.89-3(a), this Federal Order replaces Federal Order DA-2023-05 

issued April 24, 2023, and a list of the revised Karnal bunt regulated areas is published on the 

APHIS Karnal Bunt webpage. APHIS will follow this action by publishing a notice in the 

Federal Register.

For more details on the Karnal Bunt Program and federal Karnal bunt regulations, please contact 

National Policy Manager, Lynn Evans-Goldner, at lynn.evans-goldner@usda.gov or (301) 851-

2286. 

We appreciate the cooperative relationship with the Ak-Chin Indian Community, the Salt River 

Pima-Maricopa Indian Community, the wheat industry, and the Arizona State Department of 

Agriculture in the effort to limit the spread of Karnal bunt.