Items of Interest in Seed – January 2022 1 | Page

USDA Seed Regulatory and Testing Division 

Winter 2022 

EDITOR’S NOTES

Welcome to the newly formatted Items of Interest 

in Seed! The IOI will now be published quarterly 

in a newsletter format in order to provide updated 

information to our readers. We will still have 

articles featuring topics on seed testing, 

regulatory issues, and annual industry meeting 

reviews.

Recently, our laboratory staff have received 

some questions on the differences between oat 

fatuoids and wild oat; Botanist Anitra Walker has 

written an explanation. Additional articles discuss 

the oat variety fluorescence test and variety 

testing according to the Federal Seed Act.

As always, please let me know if you have 

suggestions for future topics by sending an email 

to elizabeth.stewart1@usda.gov. 

On behalf of the SRTD staff, I hope you enjoy 

these articles and continue to find them 

informative. 

Elizabeth Stewart, IOI Editor 

CHARACTERISTICS OF AVENA FATUA

Avena fatua, also known as ‘wild oat’, is a weed 

seed in the Poaceae family. Avena fatua is 

commonly found in cultivated oats. The seeds of 

Avena fatua vary in color from yellowish to 

brownish to red, and the surface is granular. The 

seed is narrowly elliptical and has an in-rolled 

lemma which usually obscures the upper palea of 

the seed. The lemma can be hairy or glabrous, 

and the basal hairs around the cavity can be long 

and spreading or short and stubby.

All florets have the twisted awns which leave an 

impression on the lemma as well as the enclosed 

caryopsis. The apex of the rachilla is triangular 

and sometimes has long, stiff hairs. The basal 

cavity (callus) is thick with a smooth rim, also 

known as a ‘sucker-mouth’. The sucker-mouth is 

formed by disarticulation from the spikelet in a 

complete abscission of the florets. This break 

occurs when the florets are at maturity. Similar 

seed that have a complete abscission and form a 

‘sucker-mouth’ as well are the homozygous 

fatuoids, ’false wild oats.’

Avena fatua, Steve Hurst, USDA-NRCS PLANTS Database

Fatuoid oats, or ‘false wild oats’, are often 

mistaken for the Avena fatua (wild oat) in certain 

varieties of cultivated oats. They have many 

similarities such as the sucker-mouth, hairy base, 

rough lemma, and the twisted awn. In general, 

differences include: a wider body similar to A. 

sativa and an exposed palea that is not as 

obscured as the A. fatua. Therefore, when trying 

to distinguish between the two, every 

characteristic should be analyzed to determine if 

it’s A. fatua. Sometimes, they are 

indistinguishable.

ITEMS OF INTEREST IN SEED
Items of Interest in Seed – January 2022 2 | Page

So, what to do if you cannot distinguish the 

fatuoid oats from the wild oats? According to the 

Association of Official Seed Analysts Rules for 

Testing Seeds, Volume 3. Uniform Classification 

of Weed and Crop Seeds section named 

‘CAUTIONS’ #4:

“4. When seeds of indistinguishable species are found 

as contaminants and may be classified either as weed 

or other crop depending on the species they belong 

to, they shall be regarded as weeds. For example, the 

seeds of lettuce, Lactuca sativa, cannot always be 

distinguished from seeds of weedy species of 

Lactuca.”

The same rule applies if you cannot distinguish 

the fatuoid from the wild oat. They shall be 

regarded as weed seeds.

Avena fatua – Sandy Dawson USDA AMS

Avena sativa, fatuoid homozygous, Sandy 

Dawson USDA AMS

References:

• (2021). Association of Official Seed Analyst 

Rules for Testing Seeds. 

• USDA – ARS Germplasm Resources 

Information Network (GRIN) www.ARSgrin.gov

• USDA Handbook N0. 30, 1952, “Testing 

Agricultural and Vegetable Seeds”

• USDA Handbook N0. 219, 1963, “Identification 

of Crop and Weed Seeds”

• The USDA-NRCS PLANTS Database, 

http://plants.usda.gov

For more information regarding this article, 

contact Botanist Anitra Walker (704) 810-7269; 

anitra.walker@usda.gov. 

OAT FLUORESCENCE TEST

When performing a purity test on oat seeds, a 

fluorescence test is sometimes requested. 

According to the AOSA Rules, a fluorescence

test determines the presence of varieties with 

fluorescent lemmas and paleas. It is performed 

by placing at least 400 seeds on a black 

background under ultraviolet light. Florets are 

then considered to be fluorescent, or a “white 

type” variety, if the lemma or palea fluoresce or 

appear light in color. 

The oat fluorescence test began in 1933 in 

Sweden at the Central Seed Testing Station. It 

was found that white, yellow, grey, and black 

grained oats showed different characteristics 

when exposed to ultraviolet light. In 1952, the 

procedure was written in the International Rules 

for Seed Testing as a cultivar test to distinguish 

between white and yellow oats. Later, several 

studies were published in determining fluorescent 

characteristics for different varieties, this led to 

listings of varietal descriptions which are still 

maintained by different State crop improvement 

associations, universities, and private seed 

companies. 

The Seed Regulatory and Testing Division 

(SRTD) uses the oat fluorescence test as a way 

to identify the presence of off-type varieties. 

According to the Federal Seed Act Regulations 

201.58a(e), “In determining the varietal purity, the 

fluorescence test may be used.” This section also 
Items of Interest in Seed – January 2022 3 | Page

describes ‘partially fluorescent’ seeds are to be 

considered fluorescent. 

The oat fluorescence test works best on freshly 

harvested, untreated seeds. Fluorescence can 

become diminished in older seeds. Caryopses

should not be included in this test since they do 

not fluoresce. 

SRTD botanists will use a description of the 

variety of the oat being tested to compare to the 

results of the fluorescence exam.

For example, the oat variety Ogle is described as 

a yellow, non-fluorescent floret. When testing this 

variety in a 400-seed separation test, any seed 

that fluoresces will be considered an off-type. 

This number is calculated into the purity data, by 

using the 400-seed separation procedure 3.1c in 

the AOSA Rules. 

Purity Analysis Percent by Weight 

Pure Seed (Oat) 98.67

Other Crop 0

Inert Matter 1.33

Weed Seed 0

If 30 non-fluorescence seed are found in a 400-

seed separation:

Kind Weight (g)

30 FL Oat .912

370 NFL Oat 11.08

Kind % by Weight % of Sample 

30 FL Oat 7.61 X .9867 7.51

370 NFL Oat 92.39 X .9867 91.16

Florescence oats found in an Ogle variety purity 

test will be classified as “other crop.” In this 

example 7.51% is enough to classify this as a 

mixture of varieties. 

Oat 400- seed separation test without ultraviolet 

light

Oat 400-seed separation test with ultraviolet light 

showing fluorescence (left) and non-fluorescence 

seeds (right)

References:

• (2021). Association of Official Seed Analyst 

Rules for Testing Seeds.

• Crommert, J. V. de. (1983). Fluorescence in 

Oats and its Value as a Varietal Purity 

Indicator. Electronic Theses and Dissertations -

South Dakota State University , 4327.

• Federal Seed Act Regulations (2020).

For more information regarding this article, 

contact Botanist Elizabeth Stewart (704) 810-

8873; elizabeth.stewart1@usda.gov.
Items of Interest in Seed – January 2022 4 | Page

ENFORCEMENT OF THE VARIETAL 

LABELING PROVISIONS OF THE 

FEDERAL SEED ACT 

The Agricultural Marketing Service’s current

policy statement is entitled, “Enforcement of the 

Varietal Labeling Provisions of the Federal Seed 

Act” in the Federal Register (Vol. 67, No. 185).

The purpose of this policy statement is to make 

clear that AMS has a comprehensive compliance 

program in place that monitors and tests seed 

shipped in interstate commerce for truthful 

varietal labeling. 

The Federal Seed Act (FSA) is enforced in 

cooperation with State seed control programs as 

authorized under cooperative agreements 

between State Departments of Agriculture and 

USDA’s AMS. Each year, the Seed Regulatory & 

Testing Division (SRTD) conducts Trueness- toVariety field tests to determine the accuracy of 

variety labeling of seed lots shipped in interstate 

commerce. Varietal identification may be based 

on seedlings, growing plants, mature plants, 

seeds, or fruit characteristics (7 CFR 201.58a). 

The authority for conducting tests and applying 

tolerances to determine the accuracy of labeling 

is contained in section 403 of the FSA (7 U.S.C. 

1593). The kinds of seed tested include field 

crops, vegetables, forages, and turf-grasses.

For more information regarding this article, 

contact Regulatory Supervisor Roger Burton (704) 

810-7265; roger.burton@usda.gov. 

USDA AMS MARKET MONITORING 

PROGRAM

Each year, the USDA Agricultural Marketing 

Service’s (AMS) Seed Regulatory and Testing 

Division (SRTD) conducts a wide variety of 

activities, under the Federal Seed Act (FSA) 

program, that promote compliance with Federal 

and State seed laws. One of these activities is 

the national Trueness-to-Variety (TTV) grow-out 

trials for select agricultural and vegetable seed 

kinds. SRTD’s TTV trials and other regulatory 

activities involve cooperating with State partners 

to collect, inspect, and test agricultural and

vegetable seeds to ensure the FSA is being 

applied uniformly across State lines. 

FSA sampling and testing activities, were once 

conducted exclusively by the Federal Seed Act 

program but have recently been performed by 

State inspectors and seed analysts. However, 

due to resource constraints amid ever tightening 

State budgets, some States have had to reduce 

their cooperative activities with AMS. These 

programs have also experienced reduced staff, 

elimination of seed laboratories, and priority 

shifts away from seed to fertilizer and other feebased programs. 

In the spirit of working collaboratively, SRTD is in 

a position to step in and help out! To this end, 

SRTD will start conducting some sampling and 

monitoring activities to help ensure truthful seed 

labeling and promote a level playing field across 

the nation. Such joint efforts with States will 

enhance enforcement of the FSA and achieve a 

comprehensive market monitoring program. All 

businesses in the U.S. seed industry play an 

important part in maintaining the high-quality 

seeds that U.S. consumers are accustomed to 

buying and selling.

For more information regarding this article, 

contact SRTD Director Ernest Allen (704) 810-

8884; ernest.allen@usda.gov. 

OECD SEED SCHEMES ASSESSMENT 

FEES 

Implementation of the Organization for Economic 

Cooperation and Development (OECD) Seed 

Schemes in the United States is administered by 

the USDA-AMS Seed Regulatory & Testing 

Division (SRTD), which serves as the National 

Designated Authority. The program helps U.S. 

seed producers export seed to many 

international destinations. 

Administration of the U.S. OECD Seed Schemes 

program is funded by assessment fees which 

SRTD collects quarterly from Seed Certifying 

Agencies (SCAs) based on the quantity of seed 

certified under the program. SCAs charge the 

seed companies accordingly along with their 

other normal charges for inspections and 

testing. Assessment fees are necessary to cover 

program costs. Major costs include the annual 

country participation fee to OECD, salary and 

benefits for the U.S. OECD Seed Schemes 

Program Manager, partial salary and benefits for 
Items of Interest in Seed – January 2022 5 | Page

a Seed Marketing Specialist who serves as the 

program assistant, travel related to program 

delivery, share of facility costs at the Gastonia 

office, and S&T and AMS overhead. 

Current assessment fee rates are 26 cents per 

hundredweight (cwt) for corn and 15 cents per 

hundredweight for all other crop species, which 

will remain through June 30, 2022. Effective July 

1, 2022, the rates will increase by 3 cents/cwt 

across the board. The new rates will be 29 

cents/cwt for corn and 18 cents/cwt for all other 

species. 

SRTD will continue to monitor program costs and 

revenue so that we can continue to effectively 

manage the OECD Seed Schemes program on 

behalf of the U.S. seed industry. Questions 

regarding the new fee schedule, or program 

policies and procedures, may be addressed to 

the program manager, Dr. Steve Malone at 

stephen.malone@usda.gov or by phone at 980-

308-4617 (mobile) or 704-810-8888.

CALENDAR OF EVENTS 

• Association of Official Seed Analysts/ Society

of Commercial Seed Technologist (AOSA/

SCST) Annual Meeting – Evanston, IL

June 4-9, 2022

• Organization for Economic Cooperation and

Development (OECD) Seed Schemes Annual

Meeting – Tallinn, Estonia

June 13-17, 2022

• Association of Official Seed Certifying Agencies

(AOSCA) Annual Meeting – Seattle, WA

June 2022

• AASCO Annual Meeting –Geneva, NY

July 2022

• 33rd International Seed Testing Association

Congress – Cairo, Egypt

May 8-11, 2022 

• SRTD Seed School – Gastonia, NC

August 2022 

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U.S. Department of Agriculture (USDA) civil 

rights regulations and policies, the USDA, its 

Agencies, offices, and employees, and institutions 

participating in or administering USDA programs 

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in any program or activity conducted or funded 

by USDA (not all bases apply to all programs). 

Remedies and complaint filing deadlines vary by 

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Persons with disabilities who require alternative 

means of communication for program 

information (e.g., Braille, large print, audiotape, 

American Sign Language, etc.) should contact the 

responsible Agency or USDA's TARGET Center 

at (202) 720-2600 (voice and TTY) or contact 

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