Types of Tests.


As a member of the Society of commercial Seed Technologists, the AB Seed Laboratory utilizes the AOSA rules for testing seeds. Inquiries of a price list should be made directly to the AB Seed Laboratory.

Purity and Noxious
The purpose of the purity test is to determine what proportion of the sample is pure seed, other crop, weed seed, and inert material. Upon receiving the sample, the analyst divides the bulk sample into a smaller sample, or working sample which is divided to the nearest minimum purity weight according to *Table 1 in the AOSA rules for the seed type to be tested. The analyst then separates the working sample into pure seed, inert material, other crop and weed seed portions. These separations are then weighed to 1/100 of a gram and percentages are determined for each component.
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Noxious Only
The purpose of a noxious-weed seed examination is to determine the rate of occurrence of any weed seed considered objectionable or noxious according to the USDA State Noxious Weed Seed Requirements recognized in the Administration of the Federal Seed Act. The sample is divided until the correct minimum weight for noxious-weed seed examination as listed in *Table 1 of the AOSA rules is obtained. The analyst then examines the sample and lists any noxious-weed seed as number found per pound.
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Germination
Upon imbition, the seed undergoes a metabolic transformation which initiates the germination process. 40 years of seed testing experience enables the analysts of the AB Seed Lab to provide the ideal environmental conditions for each particular species to maximize the germination potential. The AB Seed Lab utilizes fourteen high quality germinators/incubators for germination testing, including seven with the latest technology available obtained from Percival Scientific, INC. These numerous germinators are programmed to simulate a variety of environmental conditions as required by each individual species. During testing the percentage of normal seedlings that develop is recorded at preliminary (or first count) and final counts as dictated by the AOSA rules for testing seed *Table 3. At the conclusion of the germination test the percentage of normal seedlings is reported along with the percentage of hard or dormant seed. Any remaining ungerminated but not hard seed that are suspected to be dormant would have viability determined utilizing Tetrazolium testing and then reported as a separate dormant percentage.
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Tetrazolium (TZ)
The Tetrazolium Test is a chemical viability test which can determine potential germination relatively quickly, in most cases 24 hours. Seed is conditioned overnight, bisected through the embryo and placed into a solution of 2,3,5 triphenyl tetrazolium chloride. An oxidation-reduction reaction takes place between the tetrazolium solution and living cells within a seed to stain red when viable or potentially germinable. Since the TZ test is relatively quick it can be extremely useful when testing seeds with long or uncertain germination requirements or to determine dormancy in ungerminated seeds.
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Treated Germination
When seed born disease is potentially a cause of low germination a treated germination is initiated by coating the seed with fungicide and then conducting a regular germination test. A treated germination is a useful comparison with a regular germination test to determine if disease control is obtained by utilizing one of a variety of commercial fungicides available.
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Moisture Test
The moisture content of seeds is an extremely important factor that influences the retention of viability and carryover potential of a lot of seed. Using both the electronic steinlite moisture meter and an oven method, the moisture content of a seed sample is accurately determined to one tenth of a percent. With the oven method a known quanity of seed is weighed to one tenth of a gram and then placed in a moisture oven at 100 degrees Celsius for 24 hours. At the end of this time, the sample is reweighed and the percentage of seed weight that was moisture is determined using a mathematical formula.
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Accelerated Aging (VT)
The accelerated aging or vigor test is performed by exposing seed lots to three days of 100 F temperatures and 100% relative humidity and then conducting a standard germination test to determine how a seed lot tolerates adverse environmental conditions. Newly harvested seed should have vigor test results similar to germination results while older or less vigorous seed typically germinate much lower.
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Cold Germination Test
Along with standard germination tests, the Cold Test is recommended to simulate the unfavorable environmental factors which may prevail in the field later during planting. This test is meant to detect weakness and measure the seed's response to the wet, cold soil conditions at spring planting. Essentially the seeds are planted in soil or mixture of soil and sand, with a high moisture content and placed in the prechill germinator for seven days. After one week, the seed is transferred to an alternating 20/30 degrees Celsius germinator for completion of the germination test.
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Texas Cool Test
Similar to a Cold Test, a Texas Cool Test is performed on cotton seed by planting the seed with moist soil and exposing the seed to seven days of constant 20 degrees Celsius temperatures. After one week the cotton seedlings are evaluated to determine the percentages that form normal seedlings over 4 centimeters long when exposed to wet, cool soil conditions that may exist in the field.
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Research and Development
Inquiries about Research and Development should be directly sent to the AB Seed Laboratory. Please visit the contact page.
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Other Tests
Listed above are the most inquired about tests from the AB Seed Laboratory.Upon request, the AB Seed Laboratory is able to perform other tests. Any inquiries about other tests should be directed towards the Laboratory and/or specified when mailing the order.
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