Items of Interest in Seed – Fall 2022 1 | Page

USDA Seed Regulatory and Testing Division

Fall 2022 

EDITOR’S NOTES

This issue of the Items of Interest in Seed features 

an article on verification of seed dividers. This is a 

common practice for seed laboratories that are 

accredited. The goal of the accredited seed 

program is to promote uniformity between 

laboratories by auditing to the USDA standard and 

the Association of Official Seed Analyst rules. If 

you are interested in becoming a USDA 

Accredited Seed Laboratory, please contact us. 

The Items of Interest in Seed team is starting a 

new list serve to announce when new issues are 

posted. If you would like to be included, please 

e-mail 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 

RECENT AND UPCOMING ACTIVITIES 

CANADIAN GRADER TRAINING 

SRTD will offer a Canadian Grader training in 

early 2023 to any Certified Seed Analysts or 

Registered Seed Technicians. Analysts who pass 

the exam will be issued a grader number by the 

Canadian Food Inspection Agency. They will be 

able to assign Canadian grade names to seed lots 

moving from the U.S. into Canada, which allows 

those lots to move directly into commerce without 

the need for further testing and grading. 

To sign up for the training, e-mail 

todd.erickson@usda.gov. 

SRTD REGULATORY SUPERVISOR AND 

AGRONOMIST POSITIONS

Roger Burton, SRTD’s Regulatory Supervisor, 

retired in July. SRTD is in the process of 

advertising for a new supervisor to oversee the 

Seed Marketing Specialists. SRTD is also posting 

a job opening for an Agronomist. This position 

runs the trueness-to-variety program, which 

monitors the correct labeling of variety names for 

seed traded in interstate commerce. 

ISTA SEED SYMPOSIUM

Plant Physiologist Dr. Yujia Wu and SRTD 

Director Ernest Allen attended the International 

Seed Testing Association (ISTA) Seed 

Symposium on November 2_ 4, 2022, in Athens, 

Greece. Representatives from several countries 

participated. The symposium is held every three

years to share and improve seed scientific 

research and technical development. Several 

presentations were given orally or by poster 

sessions. 

Dr. Wu was invited to present “Polyacrylamide 

Isoelectric Focusing Electrophoresis for 

Differentiating Kentucky 31 Tall Fescue Varieties 

by Esterase Enzyme.” Dr. Wu’s presentation 

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

described his test method that identified a unique 

four band pattern in the Kentucky 31 variety, which 

was not detected in some other commercial 

varieties of tall fescue. This type of variety 

differentiation was previously only determined by

field grow-out tests. The laboratory test method 

can provide results in a much shorter time frame. 

The details of the IEF test method will be 

published by ISTA Seed Science and Technology

Journal in the upcoming year. 

Ernest Allen and Dr. Wu – ISTA Seed Symposium 2022

For more information regarding this article, contact 

Plant Physiologist Dr. Yujia Wu (704) 810-7267; 

yujia.wu@usda.gov. 

DIVIDER VERIFICATION

ISO 17025, the ISTA Accreditation Standard, and 

the USDA Accredited Seed Laboratory Program 

all require that equipment which affects test 

results to be calibrated or verified at regular 

intervals. In seed testing, this equipment typically 

includes balances, germination chambers, and 

dividers. The laboratory is allowed to set the 

intervals, provided they are justifiable. The 

standard interval used is one year, but if the 

laboratory has records to show equipment stability 

over longer periods of time, they may extend the 

interval.

Calibration involves adjusting equipment that is 

performing outside of the accepted range. 

Verification ensures that the equipment is 

performing properly, but no adjustments are made. 

While balances and germination chambers can 

have their internal settings changed, dividers do 

not have settings that can be altered, aside from 

assuring that the divider is level. Divider 

verification ensures that a sample is divided into 

two equal halves, and that there is no selection 

bias for larger or smaller seed.

There are three main types of dividers used in 

seed testing today. The gamet divider has a cone 

shaped hopper which the seed are poured into. A 

spinner attached to a motor then moves the seed 

through the hole at the bottom of the hopper, 

where it then separates into two chutes. 

Receiving pans must be placed under the chutes 

to catch the falling seed before they are poured

back into the hopper. The Boerner divider 

operates under a similar principal, except that 

gravity moves the seed through the divider rather 

than a motor. A series of baffles below the hopper 

divide the seed into the two chutes. Soil dividers 

can be used for larger seed like soybeans, or 

coated seed. Seed is poured into a rectangular 

hopper, and then passes directly through an array 

of baffles into one of two receiving pans.

The verification process is essentially the same for 

all three dividers. Two properties must be verified: 

that a sample passing through the divider results 

in two roughly equal halves, and that the 

contaminants passing through the divider, 

whether they are large or small seed, do not favor 

one chute over the other. These two properties 

can be checked with a single verification sample, 

made with a mixture of two different species of 

seed. The two species should be of different sizes, 

so they can be easily separated by sieving. One 

species should make up the bulk of the sample. 

For example, 80% watermelon seed and 20% 

tomato seed, by weight. The sample is divided a 

set number of times. The laboratory records the 

weights of seed in the two receiving pans, which 

should be approximately a 50:50 ratio, and the 

weights of the two species after dividing, which 

should closely match the initial ratio (example: 

80:20 from the example above). This process 

should be repeated at least 10 times, and the 

weight averages calculated. The tolerance applied 

to these weights is determined by the laboratory 

and can be either a percentage (generally 1% to 
Items of Interest in Seed – Fall 2022 3 | Page

5%) or based on standard deviations (2 or 3). If 

any of the reps are too far out of tolerance from 

the mean, the verification fails and must be 

repeated. The ISTA Seed Sampling Handbook 

also has a tolerance calculation that can be 

applied.

A divider which fails verification should be 

inspected before the process is repeated. 

Although rare, baffles can sustain damage and 

become mis-aligned. If a divider is biased towards 

one side, adjusting the level of the divider can 

sometimes bring it within tolerance. If moving the 

divider outside of the level position brings it within 

tolerance, then the laboratory must clearly state in 

their procedure that the divider level is not to be 

adjusted after verification.

Dividers should be clearly marked with a unique 

identifier (lab number or serial number) and date 

of last verification. Dividers which fail verification 

must be removed from service.

For more information regarding this article, contact 

Seed Laboratory Supervisor Todd Erickson (704) 

810-8877; todd.erickson@usda.gov. 

RECORD KEEPING FOR SEED

The Federal Seed Act (FSA) Section 202 requires 

that all persons transporting agricultural or 

vegetable seed in interstate commerce, shall keep 

the following records of a seed lot, for a minimum 

of three years: records of origin, treatment, 

germination, and purity. 

What actually needs to be retained? Under the 

Federal Seed Act Regulations part 201.2(I) is the 

definition of complete records. This gives the 

information needed under the following sections: 

Section 201.4 Maintenance and accessibility, 

201.5 Origin, 201.6 Germination, 201.7 Purity 

(including variety), and 201.7a Treated Seed. A 

great source to review is a publication on the AMS 

SRTD website, https://www.ams.usda.gov/rulesregulations/fsa, find the tab Seed Company 

Records and the Federal Seed Act. 

For more information regarding this article, contact 

Seed Marketing Specialist Rodney McNeace 

(704) 810-8879; rodneyb.mcneace@usda.gov. 

FEDERAL SEED ACT CASES SETTLED

The Federal Seed Act (FSA) provides authority for 

the regulation of the interstate shipments of 

agricultural and vegetable seeds. The FSA 

requires that seed shipped in interstate commerce 

are labeled with certain information necessary for 

the seed buyer to make an informed choice. The 

labeling information and any advertisements 

pertaining to the seed must be truthful. Between 

September 1, 2021, and August 31, 2022, a total 

of 37 seed companies paid $98,100 to settle 

alleged violations of the FSA.

For specific information regarding these violations, 

please visit https://www.ams.usda.gov/rulesregulations/fsa then Filing a Complaint and View 

a list of settled FSA Cases . USDA’s Agricultural 

Marketing Service (AMS) administers the FSA by 

leveraging its resources with State departments of 

agriculture. These investigations were a result of 

joint efforts with seed regulatory officials in 

Arkansas, Connecticut, California, Florida, 

Georgia, Illinois, Indiana, Kentucky, Louisiana, 

Maryland, Michigan, Missouri, New York, North 

Carolina, Pennsylvania, Texas, Utah, and Virginia. 

By working collaboratively with State partners, 

Seed Regulatory and Testing Division helps 

promote uniformity among State seed laws and 

fair competition within the seed trade through the 

enforcement of the FSA.

For more information regarding this article, contact 

Seed Marketing Specialist Kevin Robinson (704) 

810-7264; kevin.robinson2@usda.gov. 

TRUENESS-TO-VARIETY OVERVIEW

Each year the Seed Regulatory and Testing 

Division (SRTD) conducts trueness-to-variety 

(TTV) field tests to determine if seed lots are 

correctly labeled as to variety. Varietal evaluations 

are conducted by crop experts at State 

Universities and State departments of agriculture 

in cooperation with SRTD. SRTD relies on State 

seed control programs to submit the samples for 

inclusion in the TTV tests.

This summer, sweet corn is being grown at 

Purdue University, West Lafayette, IN. In addition, 

melons, cucumbers, and garden beans, are 
Items of Interest in Seed – Fall 2022 4 | Page

currently being evaluated at the Piedmont 

Research Station, Salisbury, NC. 

SRTD would like to thank all the States for 

participating in the TTV program. Once results and 

information have been compiled, participating 

States will be notified of the evaluation results. 

For more information regarding the TTV program 

or directions for submitting samples, contact Seed 

Marketing Specialist Alvin Allen (704) 810-8878; 

alvin.allen@usda.gov. 

CALENDAR OF EVENTS 

• OECD Technical Working Group Meeting

Paris, France 

January 23-27, 2023

• ISTA Annual Meeting 

Verona, Italy

May 29-June 3, 2023

• Association of Official Seed Certifying 

Agencies (AOSCA) Annual Meeting 

Bloomington, MN

 June 3-7, 2023 

• AOSA/SCST Annual Meeting 

Saskatoon, Canada 

June 9-15, 2023

• Organization for Economic Cooperation and 

Development (OECD) Seed Schemes Annual 

Meeting 

Antalya, Turkey 

June 19-23, 2023

• SRTD Seed School 

Gastonia, NC 

 August 2023 

 

In accordance with Federal civil rights law and 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 

are prohibited from discriminating based on race, 

color, national origin, religion, sex, gender identity 

(including gender expression), sexual orientation, 

disability, age, marital status, family/parental 

status, income derived from a public assistance 

program, political beliefs, or reprisal or retaliation 

for prior civil rights activity, in any program or 

activity conducted or funded by USDA (not all 

bases apply to all programs). Remedies and 

complaint filing deadlines vary by program or 

incident. 

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 

USDA through the Federal Relay Service at (800) 

877-8339. Additionally, program information may 

be made available in languages other than English.

To file a program discrimination complaint, 

complete the USDA Program Discrimination 

Complaint Form, AD-3027, found online at How 

to File a Program Discrimination Complaint and at 

any USDA office or write a letter addressed to 

USDA and provide in the letter all of the 

information requested in the form. To request a 

copy of the complaint form, call (866) 632-9992. 

Submit your completed form or letter to USDA by: 

(1) mail: U.S. Department of Agriculture, Office 

of the Assistant Secretary for Civil Rights, 1400 

Independence Avenue, SW, Washington, D.C. 

20250-9410; (2) fax: (202) 690-7442; or (3) email: 

program.intake@usda.gov. 

USDA is an equal opportunity provider, employer, 

and lender.