Seed Laboratory

AOSA Purity Test (p) This test determines the percentage by weight of pure seed, other crop seeds, inert matter, and weed seeds in a test sample. This test can be conducted on commercial, certified, official, and other samples. When a customer orders an AOSA purity test, the lab also conducts and reports an all-states noxious weed exam, see below. *ISTA Accredited Test

AOSA Noxious Weed Exam This test reports the name and number of any noxious weed seeds found in a test sample (minimum 25,000 seeds) based on the Federal all-states noxious-weed seed requirements. A noxious exam for a particular state such as Hawaii or Wisconsin can be performed as well. The test does not report other seeds that are not in the noxious list. The noxious exam is required by the Oregon Certification Program and is automatically conducted when an AOSA purity is ordered.

ISTA Purity Test (ista/p) This test determines the percentage by weight of pure seed, other seeds, and inert matter. The minimum sample size is 2500 seeds (see the ISTA International Rules for Seed Testing for more details). ISTA Orange and Blue Certificates can only be issued for species listed in the ISTA Rules, Chapter 2. 

https://www.seedtest.org/en/international-rules-_content---1--1083.html

Undesirable Grass Seeds (UGS) The UGS test is an examination of a test sample (minimum 25,000 seeds) for ten species deemed undesirable in seven eastern states (MD, VA, WV, PA, NJ, NH and DE). These species are bentgrass, bermudagrass, annual bluegrass, rough bluegrass, meadow fescue, tall fescue, orchardgrass, redtop, timothy, and velvetgrass. When marketing turf varieties into the listed states, the seed label must list the name and number per pound or ounce of UGS species found in a test sample under the heading "Noxious Weed Seed" or "Undesirable Grass Seed". This test can be conducted on commercial, certified, or official samples.

AOSA Crop & Weed Exam (CW) This exam provides a complete listing of all species (both crops and weeds) found in a test sample (minimum 25,000 seeds) and categorizes the seeds as crop seeds or weed seeds. Both the actual number of seeds found in a test sample (e.g., 1 seed in 50g) and the rate of occurrence (number of seeds per pound) are reported. Because the CW test provides complete listing of all the seeds found in a test sample, Oregon Sod Quality and UGS reports can be generated in most cases without testing the sample again, saving time and money for customers. This test can be conducted on commercial, certified, official or other samples. It is required for Certified AOSA/EC basic and pre-basic tagging, Canada testing, and WA Sod Quality.

ISTA Other Seed Determination (OSD) (also called Determination of Other Seeds by Number) This test determines the number and identity of other seeds in a test sample. The extent of this determination is referred to as the scope of the test. The scope depends on customer needs: *ISTA Accredited Test 

• Complete in which the whole working sample (minimum 25,000 seeds) is searched for all other seeds present (this equates to the AOSA C&W exam).
• Limited in which the search is restricted to stated species in the whole working sample.
• Reduced in which only part of the working sample is examined for all other seeds.
• Reduced-Limited in which only part of the working sample is examined for stated species only.

Soil Exam Determines the percentage of soil particles in the working sample. Can be performed as a sequential test (i.e. other tests will be done only if soil exam results are within a certain specification). *ISTA Accredited Test

Oregon Sod Quality Exam (SQ) (Certification eligible samples only.) Search for specific crops and weeds as defined by the program. Sod tests are stopped if disqualifying contaminants or amounts of contaminants are found. Please see the Oregon Sod Quality page for more information.

Pest and Disease Exam The working sample is examined for a list of pests and diseases. Affected seeds are removed, identified, weighed and reported by percentage.

Ergot A test to detect Ergot (Claviceps purpurea) in a sample. The ergoted seeds are removed, weighed and reported as percentage. *ISTA Accredited Test

Orobanche Test Determines the presence of Orobanche seeds in a submitted sample of red clover using a dry method. This test requires its own sample. *ISTA Accredited Test

Dodder and OR Prohibited Exam Certified alfalfa and red clover samples must be tested using a dodder mill. The material removed is examined for dodder or any other Oregon prohibited weeds. A 500g bulk examination is required for certification purposes.

Noxious/Prohibited Tests for Other Countries A test performed at customer request. The noxious weeds list varies with the country. The customer must provide a current list of noxious/prohibited weeds of the particular country.

Seed Test Weight

• Weight per bushel (lbs/bu)
• Seed count (1000 seed wt, seeds per pound, etc) *ISTA Accredited Test

Seed weight can indicate seed size, density, and the presence of shriveled, small, less developed seeds in a lot. Depending on the variety, production site, and rainfall during the growing season, there can be significant differences in the number of seeds per pound. This test helps in determining the seeding rate.

Germination A physiological viability test which determines the percentage of live seeds that produce normal seedlings under favorable germination conditions. Both AOSA and ISTA require 400 seeds for germination in most cases. *ISTA Accredited Test

ISTA Germination Test (ista/g) This test determines the germination percentage of the seed.

Fluorescence Test for Ryegrass This test requires germinated seedlings, and determines the fluorescence level of any particular ryegrass sample. It is used to estimate a potential contamination of perennial ryegrass with annual ryegrass. This test is performed on all AOSA ryegrass germinations and is used to differentiate Annual from Perennial ryegrass under AOSA rules. It is performed on ISTA samples by request and is not used in ISTA purity calculations. 

Ammonia Fluorescence Test for Fine Fescue: A quick test to distinguish between Festuca ovina and Festuca rubra. The roots of F. rubra fluoresce yellow and the roots of F. ovina fluoresce green when sprayed with a 0.5% solution of ammonium hydroxide. This test is performed on all AOSA fine fescue germination tests. It is performed on ISTA samples by request. *ISTA Accredited Test

Fluorescence Grow-out for Ryegrass: A test involves growing fluorescent ryegrass seedlings using a specific protocol. At the end of the prescribed test period, the plants are evaluated according to their growth habits. The data is used to make AOSA purity calculations as to the percentage of perennial and annual ryegrass in a sample. Growout results may be reported on an ISTA certificate but the results are not used in ISTA purity calculations.

Grow-out of Other Species: A test in which seedlings are grown in greenhouse conditions until they develop characteristics that allow them to be differentiated. This is applicable to a wide range of species and is useful in conditions where normal purity determinations cannot be made with certainty.

Varietal Fluorescence Level (VFL): This test is required by the National Grass Variety Review Board before releasing a new ryegrass variety describing its inherited fluorescence level or to re-describe an existing variety. It involves fluorescence tests of at least 3000 seeds and a grow-out of the fluorescing seedlings following a specific protocol.

Tetrazolium (TZ) A quick biochemical viability test which determines the number of live seeds based on dehydrogenase activity in seeds. It indicates the percentage of viable (live) and non-viable seeds in any sample regardless of its dormancy level. The test can be performed in 24-48 hours. *ISTA Accredited Test

ISTA Tetrazolium (ista/tz) This test determines the viability percentage of the seed.

xxx

Cold Test (CT): A vigor test that indicates the potential emergence of seeds under early spring field conditions where cold and wet soils are prevalent. Used for corn, beans, peas, and vegetables that are planted in the early spring. 

Accelerated Aging (AAT): A vigor test, where seeds are stressed with high temperature and relative humidity for a period of time prior to the germination test. High quality seeds tolerate such stress conditions and retain their capabilities to produce normal seedlings when germinated.

Conductivity Test (CT): A test to measure the integrity of the cell membranes. Low vigor seeds have leaky membrane structure and release electrolytes into the soak-water. The level of electrolytes is reflected in high electric conductivity of the soak-water.

Speed of Germination (SG): High quality seeds germinate faster than poor quality seeds.  The number of normal seedlings recorded in the first count represents the population of fast germinating seeds and thus functions as a vigor measurement (AOSA Seed Vigor Testing Handbook). 

Ploidy by Cytometry: A test separating diploid and tetraploid ryegrass genotypes, or any genotypes with different chromosome numbers based on the amount of DNA in the nucleus of plant cells. This test can be performed on germinated seedlings or leaf tissue from the greenhouse or field. Currently it is being used for research projects in a broad range of crops.

Phenol Test: A quick test for cultivar identification. It is based on color reaction between phenol solution and seed coat (pericarp). It can be used for wheat, barley, oat, ryegrass and bluegrass.

When a test sample is compared with a pure control check, it can be determined if the sample is pure or mixed with other cultivars.

Clearfield Wheat Bioassay: Determine the percentage of the “Clearfield®” trait (a herbicide tolerant trait) in a population of 400 seed sample that represents a seed lot. The test is completed in approximately 10 days.

Sodium Hydroxide Test for Wheat (NaOH): A chemical test used to distinguish between red and white wheat in situations where it is difficult to distinguish between the two types (i.e. when seeds have been weather-damaged, treated, or are simply hard to distinguish by the naked eye).

Blackleg Testing: A test that detects the presence of Phoma lingam (Leptosphaeria maculans) on seed. The test is for Brassica species: canola, kale, turnip, cabbage, cauliflower, etc.

Endophyte: A test to detect the presence or absence of endophyte fungi (Neotyphodium spp.) in seeds. It helps growers to make decisions regarding the marketing of grass seeds for feed or turf purposes.

Mosaic Virus Testing: A test that detects the presence mosaic virus on seed. This test is for squash, tomato, pepper, cucumber, potato, and other species of garden seed.

Seed Moisture Content: This test determines the percentage by weight of moisture content in seeds. Seed moisture content affects the capacity of seeds to stay alive and maintain germinability and vigor over time. *ISTA Accredited Test

Oil and Protein: Using Nuclear Magnetic Resonance Spectrometry (NMR), we can determine oil, protein, and moisture content in seeds of various oil crops. The test is non-destructive and the machine can be calibrated for a wide range of crops. Read more.

Chemical tests to detect mechanical damage and seed coat injuries: Fast green, Ferric chloride and Indoxyl acetate tests are used to reveal mechanical injuries and physical fractures in seed coats of corn, soybeans, and other seeds.

Thermogradient Germination Test

• Identifies the optimum germination temperatures for various crops.
• Screens varieties for cold and/or heat tolerance.
• Determines the relative quality of different seed lots.

Custom Testing Research projects for seed companies, research, and extension educators

This customer-driven area focuses on any seed related research in response to specific needs of others including research, extension, and industry customers that are working on seed related projects. The following are some examples that were completed in the last few years:

Examples of Completed Projects

• The effect of maturity stages on purity and viability of some native species.
• Germination and dormancy studies of native species such as sedges (Carex mertensii).
• Purity and TZ study to identify, quantify, and measure the viability of bird seeds
• The effect of heat treatment on breaking seed dormancy and increase germination of seeds.
• Seed search in soil samples to understand persistence of crop, weed, range seeds, etc.
• Germplasm screening of California brome by ploidy level.
• Ploidy germplasm screening for St. Augustinegrass and other species.
• Effects of various seed coating on germination of some grasses.
• Effect of seed coating on germination and vigor of Bluegrass.
• Ploidy evaluation of Brassica species.
• Effect of seed coating on germination and growth performance of selected grasses.

Visit the old page: https://seedlab.oregonstate.edu/seed-testing-services