Understanding Seed Labels
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Estoy de Acuerdo / I agree
As a horse owner, you always have to think ahead in order to stay ahead. Even though we are in the winter months now, Spring is right around the corner which means you should be thinking about Spring pastures and possibly pasture renovations. Here are a few helpful hints to make sure that you are getting the best seed for your money.
There is a “Seed Law”. This law requires seed being sold to adhere to a minimum set of guidelines and standards which should be listed on a suitable label. Access the North Carolina Seed Law. There are certain exemptions and additional standards which can be found in the NC Administrative Code Title 2, Subchapter 48C. Not all bags of seeds are created equal, even if they follow the seed law. There is a large amount of variation in seed quality. Adherence to the seed law only guarantees that the bag of seed you are purchasing meets the claim on the bag so it is important to shop around and compare labels.
So what has to be on the label? What does this information mean? (Information from “A Simplified Guide to Understanding Seed Labels”)
- Variety and Kind – Cultivar/release name, species and common name
- Lot number – A series of letters or numbers assigned by the grower for tracking purposes
- Origin – Where the seed was grown
- Net weight – How much material is in the container
- Percent pure seed (purity) – How much of the material is actually the desired seed
- Percent inert matter – How much of the material in the bag is plant debris or other materials that are not seed
- Percent other crop seeds – Other non-weed seeds
- Percent weed seeds – Seeds considered weed species
- Name of restricted noxious seed (with number per pound of seed). Noxious weed species vary by state. There are 2 types of noxious weeds – restricted and prohibited. Restricted weeds are listed as number of seeds per pound of material in the bag. There should be NO prohibited weeds.
- Percent germination (germ) – An average percentage of seed that will germinate readily
- Hard seed – Seed which does not germinate readily because of a hard seed coat
- Dormant seed – Seed which does not germinate readily because it requires a pre-treatment or weathering in the soil. (Some suppliers may combine hard and dormant seed on the label).
- Germination test date – Date should be within 12 months of the planned date for using the seed
- Name and address of the company responsible for analysis (seller or grower)
The Natural Resources Conservation Service’s Plant Materials Program recommends using seed labels to help you shop around for the best value that will meet your needs. They suggest that you always check the purity/germination and if it is very low, you might not want that variety or mix. If noxious weeds are listed on the tag, take into account that they could most likely become a problem in your pasture by becoming hard to control and outcompeting your desirable grass. NRCS also suggests that you purchase seed based on the Pure Live Seed (PLS) which you will use to calculate the amount of seed you will need for planting. Their calculations are as follows:
You need to determine viability first.
Viability = germination + hard seed + dormant seed
The second step is to calculate the amount of Pure Life Seed (PLS).
PLS = (%purity x %viability) / (100)
Finally, to calculate the amount of seed needed for planting. . .
Bulk seed/acre = (lbs. of PLS recommended per acre) / (percent PLS)
Seed inspectors visit dealers regularly to spot check seeds. During checks, inspectors take random samples of bags to have them analyzed for accuracy by NCDA&CS Seed Lab. If there is a discrepancy in the sample versus its label, a “stop-sale” notice is issued until the seed is brought back within standard and meets the label claims. Inspectors and dealers usually work together to make sure that consumers are being supplied the best seed possible.
Now that you hopefully have a better understanding of seed tags, go ahead and start shopping around for your spring pasture needs. For more information, please contact your local Agriculture Extension Agent.
Englert, J.M. 2007. A Simplified Guide to Understanding Seed Labels. Maryland Plant Materials Technical Note No. 2. USDA-NRCS National Plant Materials Center, Beltsville, MD. 3p.
Ferguson, J.M., et al. 2017. Seed and Seed Quality. AG-448. NC State Extension. Raleigh, NC. 29p.
Jamie Warner Extension Agent, Agriculture – Livestock and Forestry Call Jamie
NIH Research on Marijuana and Cannabinoids
The NIH supports a broad portfolio of research on cannabinoids and the endocannabinoid system. This research portfolio includes some studies utilizing the whole marijuana plant (Cannabis sativa), but most studies focus on individual cannabinoid compounds. Individual cannabinoid chemicals may be isolated and purified from the marijuana plant or synthesized in the laboratory, or they may be naturally occurring (endogenous) cannabinoids found in the body.
Cannabinoids are classified here as:
- Phytocannabinoids – cannabinoids found in leaves, flowers, stems, and seeds collected from the Cannabis sativa plant.
- Endogenous – cannabinoids made by the body: examples include N-arachidonoylethanolamine or anandamide (AE) or 2-arachidonoylglycerol (2-AG). AE and 2-AG activity can be manipulated by inhibiting their corresponding hydrolases FAAH or MAGL, preventing their degradation.
- Purified naturally occurring cannabinoids purified from plant sources: examples include cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC),.
- Synthetic cannabinoids synthesized in a laboratory: examples include CB1 agonists (CPP-55, ACPA), CB2 agonists (JWH-133, NMP7, AM1241), CB1/CB2 nonselective agonist (CP55940), ajulemic acid (AJA), nabilone, and dronabinol.
There is considerable interest in the possible therapeutic uses of marijuana and its constituent compounds (see NIDA’s DrugFacts, Is Marijuana Medicine?). In 2015, the NIH developed three reporting categories to describe the research efforts underway to examine the chemical, physiological, and therapeutic properties of cannabinoids and the physiological systems they affect.
- Cannabinoid Research reports the total NIH investment in all cannabinoid research including basic research, animal and human preclinical studies, and clinical research. Studies examining cannabis use disorder and societal/health impacts due to changing marijuana laws and policies are also included. Studies examine all classes of cannabinoids (purified, synthetic, endogenous, phytocannabinoids), molecules that modify their concentration or activity (e.g. FAAH inhibitors), as well as the physiological systems they target (e.g. endocannabinoid system).
- Cannabidiol Research – subset of the Cannabinoid Research category that reports all NIH projects examining basic, preclinical, and therapeutic properties of CBD.
- Therapeutic Cannabinoid Research – subset of the Cannabinoid Research category (above) that reports all NIH projects examining the therapeutic properties of all classes of cannabinoids (purified, synthetic, endogenous, phytocannabinoids).
These categories are publically accessible on the NIH Categorical Spending website and will be updated annually.
Colorado State University
Contact your local county Extension office through our County Office List.
Improve Yield With High Quality Seed – 0.303
by M.A. Brick * (12/14)
- Seeds are one of the least expensive but most important factors influencing yield potential.
- Seed quality is determined by germination and purity analysis.
- By law, all crop seeds must be labeled for germination percent, crop seed, weed seed and inert matter content, and the date of germination test.
- Purchase seed stock from a reputable seed dealer who has proper cleaning, handling and storage facilities.
Seeds are one of the least expensive but most important factors influencing yield potential. Crop seeds contain all the genetic information to determine yield potential, adaptation to environmental conditions, and resistance to insect pests and disease.
One of a farmer’s most critical management decisions is the selection of seed source and variety. The cost of seed stocks usually is less than 5 to 10 percent of total production costs. Yet seed stocks can affect the yield potential of a crop more than any other input factor.
Seed quality is determined by many factors, principally seed purity and germination. However, many other factors, such as the variety, presence of seed-borne disease, vigor of the seed, and seed size are important when considering seed purchase.
Seed purity is determined by the amount of unwanted material present in the pure seed. Contaminants such as noxious weed seed, unwanted crop seed or inert matter not only increase production costs, but also substantially reduce the quality and quantity of the harvest. If you purchase seed that has not been properly conditioned to remove unwanted weed seed, include in your decision-making the increased herbicide cost to control newly introduced noxious or common weeds.
Seed germination tests assess the ability of the seed to produce a healthy plant when placed under favorable environmental conditions. Germination tests are conducted for a prescribed time period under laboratory conditions that assure optimum moisture, temperature and light. Unfortunately, these conditions are seldom encountered in the field, and field emergence may be overestimated by standard germination tests.
Seed lots that have low germination also are less vigorous due to seed deterioration. As seeds deteriorate, loss of vigor precedes loss of viability, so seeds with low germination usually will be less vigorous. Hence, in seed lots with poor germination, those seeds that do germinate often produce weaker seedlings with reduced yield potential. However, some species (such as many native grasses) have inherently low germination potential and cannot be assumed to have poor vigor due to low germination.
Varietal purity indicates genetic purity of the seed. This factor is extremely important in obtaining pure stands of a specific variety. Varietal mixtures can cause uneven maturity, lower yield potential, increased susceptibility to disease and insect pests, and be less adapted to specific environmental conditions.
Varietal mixtures are difficult to detect through examination of the physical characteristics of the seed. Seed certification programs and many seed companies rely heavily on inspection of the seed production field to assure varietal purity. When choosing seed stocks, select those that are labeled by variety name, preferably certified seed. When you purchase certified seed, obtain proper documentation to prove that the seed has been certified, such as a certified seed tag or bulk sales certificate that shows the variety by name.
Seed vigor usually cannot be assessed by the Consumer. Germination and seed size (in the case of cereal grains) often are good indicators of seed vigor. However, in the case of hybrid varieties, seed size or plumpness is sometimes not related to seed vigor. Research in Kansas and other states shows significant yield increases when large seeds were compared to small seeds from the same lot. These differences were accentuated when deep planting was used and point out the need to remove the small seed during seed conditioning.
State and federal laws require that all agricultural seed be labeled. Labeling requirements for some flower, tree and shrub seeds may differ. If the seed has been treated a label must state the seed has been treated, the commonly accepted coined chemical name of the applied substance, and if the substance in the amount present is harmful to human or other vertebrate animals, a caution statement such as “Do not use for food, feed, or oil purposes.” Toxic substances shall be labeled with a poison symbol. Terms that must appear on the label are:
- varietal name and kind of seed;
- lot number;
- percentage by weight of pure seed;
- percentage by weight of all weed seeds;
- percentage by weight of all crop seeds;
- percentage by weight of inert matter;
- name and number per pound of restricted noxious weed seeds; and
- the date of the germination test.
Terms that appear on the label are:
Variety name: The name of the kind or kind and variety for each agricultural seed component present in excess of 5 percent of the whole and the percentage by weight of each. If the variety is not stated, the label shall show the kind and the words “Variety Not Stated” or “VNS”. Hybrids shall be labeled as hybrids.
Lot Number: A lot number or other lot identification.
Origin: State or foreign country of origin if known; if not known, the fact shall be stated.
Pure seed: The percentage by weight of crop seed compared to other components. The best quality seed is nearly 100 percent pure. To meet certified seed standards for small grains, seed must be more than 98 percent pure.
Other crop seed: The percentage by weight of any other crop seed in the test sample.
Inert matter: The percentage by weight of sand, sticks, broken seed parts and other foreign material in the seed. This percentage is small in high-quality seed. Higher percentages of inert material will increase the cost of the remaining pure, live seed.
Weed seed content: The percentage by weight of weed seed. State seed regulations do not allow any prohibited noxious weed seeds to be present. Any restricted noxious weed seed content must be listed on the label.
Germination: The percentage of germination, exclusive of hard or dormant seed. The percentage of dormant or hard seed if present and the calendar month and year the germination test was completed. The date of test should be within the previous 13 months on the time of sale to ensure the quality of seed and to comply with seed laws.
Labeler: The name and address of the person who labeled the seed, or who sells, offers or exposes the seed for sale within the state.
Purchasing Quality Seed Stock
High quality seed can be purchased from any reputable seed dealer who has experience in producing, conditioning (cleaning) and storing seed stocks.
During seed production, proper fertilization, adequate water, sufficient isolation (for cross pollinated Crops), proper roguing of off-types, and timely harvests are all important factors. Care also must be taken to clean harvesting equipment, trucks, and storage and handling facilities to prevent contamination. During the conditioning and packaging process, the seed must be handled carefully to avoid contamination and damage.
Proper seed moisture at the time of packaging and seed treatment also are important considerations. Seed storage conditions must maintain the vigor and quality of the seed. Excess humidity or heat can cause severe damage to seed in a short time.
Seed dealers should have the capability and facilities to provide the conditions listed above. Their reputation as quality seed dealers usually is a good indicator of the quality of seed offered for sale. Don’t hesitate to ask questions regarding the origin of the seed and appearance of the seed field. If the dealer is a neighbor, ask to see the seed production fields prior to harvest.
* Colorado State University Extension specialist, soil and crop sciences and director of Colorado Seed Programs. 3/95. Revised 12/14.