A Look into the N.C. Seed Laboratory

“We want to not only help and protect those who plant the seed, but the ones who produce it, too,” said Dr. Dianne Farrer, the Seed & Fertilizer Administrator of the Plant Industry Division. With the N.C. Department of Agriculture and Consumer Services, The N.C Seed Laboratory’s mission is to ensure the truth in labeling with seeds. Located in Raleigh, the lab provides germination percentage, seed quality and purity tests for homeowners/consumers, farmers and seed production companies.

A red brick building with three levels, diverging in almost a castle-shape. Many windows line the building.
This is the building that the N.C. Seed Lab is kept in.

Within the Plant Industry Division, there are two major sections: Plant Protection and Seed and Fertilizer. The N.C. Seed Laboratory focuses on seed regulation and services. The process all begins when someone sends seeds to the lab. “There are two types of seed samples that come to us,” said Dr. Farrer, “Official seed samples and service seed samples. Official seed samples are collected by our field inspectors and are regulated according to state laws and rules, including issuing a stop sell. With service seed samples, that comes from just about anyone including seed companies, farmers, seed processors and small hardware stores. All we can do for them is offer recommendations about germination or purity of their seed.”

“A stop sale order is triggered when the seed label or the germination test results or test date are not in alignment with the state statutes, rules and regulations,” said Dr. Farrer. The reason these state regulations exist is to ensure all those who use the seed know what seed they are putting in the ground and how well they will germinate, which helps ensure a good product for farmers and consumers. If a seed had a low germination rate, that would not be beneficial to anyone planting that seed. That is why N.C. Seed Lab offers services to help determine the germination for not just farmers, but all various seeds across the state of North Carolina.

A lab space with white bags that hold seeds, red tubs with paper work, and baskets with seed packages that need to be sorted.
White bags with seeds in them on a tray with a fan in the background.
Plant seeds from all across the state are sorted in this room

Regardless of seed sample type, there are many different tests they can go through. The most common test for these seeds is germination. Germination is when a dormant seed begins to grow into a new plant,” said Dr. Farrer. “Instead of planting the seed in soil, we simulate growing conditions by putting seeds onto moistened paper towels and letting them grow. That way, it keeps the seed free from diseases and fungi that might be present in soils, while providing the optimum growing conditions for each kind of seed.”

Some lima bean looking seeds that have roots sprouting out from them on a brown paper towel.
Germinated soybeans on a paper towel

To grow a seed this way, the seed goes through a careful preparation process to equally distribute the seeds across the paper towel used. Some smaller seeds, such as grass seeds, require a petri-dish to grow on instead of a paper towel environment.

Pieces of wood with holes placed neatly in them. The mechanism is a piece of board attached is slid out and the seed falls through.
For seeds to be placed perfectly, seeds are placed in the holes of this tool. Then, the bottom is removed, causing the seeds to fall onto the paper towel evenly.
A box with a tube attached to a flat frame with green pelt used to suck up seeds
A seed dispenser similar to the one above, except it uses vacuum power to pick up and place smaller seeds.

Once carefully placed and rolled into the paper towel, the seeds are placed into large machines that are essentially reverse refrigerators called germinators. Instead of keeping things cold, these machines keep things warm. In addition to keeping the plants warm, germinators provide light for the plant and keep air flow constant to have the seed in the best environment possible for maximum growth or germination.

A fridge looking scene with cardboard, sealed boxes of seeds within.
The inside of a germinator. Those baskets are filled with plant seeds being germinated.
Eight containers that look like fridges that are actually germinators
A long line of germinators prepping seeds to be examined

Once fully germinated, the expert seed analysts look at the strict criteria for germinated seeds to see which pass the test and which do not. When they find the ones that do not work, they list the reasons why on a criteria sheet. Once the results are in, they carefully package and store the leftover seed within a climate-controlled room to keep the remaining seeds viable in case there is a requested retesting of the seed. “Our service seed samples we get are stored for around three to four months while our official seed samples usually stay for up to a year,” said Dr. Farrer. “The reason why they are kept so long is to have enough seed for additional tests or if customers request retests.”

A windowless room with black shelves lining the walls. Tons of white boxes are stacked on these shelves.
The storage room where official seed samples are stored.

Besides the germination test, there are several other tests conducted at the lab including purity tests. This test shows the quality of the seed via physical inspection under tools such as microscopes. For reference in identification of these seeds, seed analysts use a herbarium, or a collection of preserved and labeled seeds.

A black microscope with a small petri-dish underneath it. On the screen, the barely visible petri-dish is seen clearly with small seeds within.
This microscope is used to zoom in and inspect the quality of seeds. Right now, it is inspecting a batch of white clover seeds.
A cabinet with drawers that hold dozens of small tubes of seeds.
This tall cabinet of drawers houses the Herbarium, which has hundreds of samples to use as identification for seeds.

Within the N.C. Seed Laboratory, the staff is highly experienced and have very keen eyes and skills to identify seeds and to process them. Some of the interesting equipment found can be seen below:

A blue and black box that has a screen, a number pad, and a screen to display information.
This machine is known as a grain moisture/test weight machine. Back in the 1980’s, it was used to obtain test weights and grain moisture before such measurements were a standard part of combines used in harvesting grains, valuable information when trying to sell your grain at a local elevator or feedmill.
Two machines: a blue one and a silver one. Both have a tube rising from the front and the middle of the machine, where the seeds are blown and the trash is separated.
This machine is known as a blower. It is used to separate seeds and trash (or, as called in the lab, inert matter).
A silver machine with a space in the top for where seeds fall down into it. Two tubes stick out the sides to separate the seeds.
A divider machine is used to unbiasedly separate seed samples into smaller working sizes/weights for further laboratory analysis.

With the help of the N.C. Seed Laboratory, stores, farmers, processors and consumers can have their seeds tested to find the optimum germination percentage the seeds will have, the quality and the purity of their seed. “During the summer, since most agriculture seeds are in the ground, we try to focus on homeowners or consumers more,” said Dr. Farrer. “We do this by checking on the seeds of popular stores such as Lowes, Tractor Supply and Walmart. After all, we want to help not only farmers, seed companies and producers, but homeowners or avid gardeners as well.”