b'Seed Trade Associationsfor purity and foreign seed tomant seeds. So why is that? (ASTA) director of stateestablish a baseline. A sub- We have seen the trend; now affairs. In any process, Isample for each species waswe have to figure out why. believe there is always roomsubmitted to the seed testingThe accuracy of TZ test for improvements, innovationslabs without the purpose ofresults is very dependent on and efficiencies. I hesitate tothe test being revealed. the expertise of the analyst speculate on the outcomes,Seed labs tested the seedand their level of familiarity but I am certain this surveysamples to obtain the requiredwith the morphology of the will generate positive actionseed label information. Theembryo structure of the seed for everyone involved in thelabs returned test reports tokind being tested.seed industry, including ourthe respective seed compa- Goltz believes a large part seed customers. nies. Tetrazolium (TZ) dor- of seed control officials work ASTA and AASCO cooper- mancy tests were performedis education. ated to select 12 seed testingon three species: Indiangrass,When I run into a regula-labs that offer services for apurple prairie clover and bigtory violation, it comes down fee to seed producers and tobluestem. to intent. Did the individual the public. Corporate labs thator company understand they test only their own seed wereNatives, PLS and TZ tests were violating the law? If no, not included. ASTA membersDenise Thiede, manager ofthen it is an education prob-donated seed and paid forthe Seed, Noxious weed,lem. If yes, then it is an ethical the seed testing. ASTA andHemp, and Biotechologyissue. If a seed lab comes toUniformity hasAASCO provided additionalprograms of the Minnesotathe top more often because it financial support for the survey. Department of Agriculture,is out of tolerance more thanbeen a challenge in Nine seed lots receivedsays native seeds, as well asothers, the question becomes,seed testing everfrom ASTA members wereother seed with a significantIs this a proficiency issue? Or used in the study: Bigamount of dormant or hardis it more along the ethicalsince seed testing bluestem (Andropogonseeds, is sold based on purelines? We dont know. Thats gerardi Vitman), Germanlive seed (PLS). The value ofgoing to be the next stepstarted in the(Italian) millet (Setaria italicaa seed lot is determined byfrom our perspective. Why islate 1800s.subsp. Italica), Indiangrassthe amount of PLS is calcu- this happening? I think that is (Sorghastrum spp.), Kentuckylated from a TZ test score.where AOSA and SCST are David Johnstonbluegrass (Poa pratensis L.),Determining seed viabilitycurrently working.oat (Avena sativa L.), Pearlusing triphenyl tetrazolium millet [Cenchrus americanuschloride (TZ test) is not aNoxious Weed Seed (L.) Morrone], Purple prairie- simple, black and white test.Violationsclover (Dalea purpurea Vent.),Viability determination via TZAn analysis that is often even rye (Secale cereale L. subsp.analysis requires an analyst tomore critical than TZ test-Cereale) and wheat (Triticumevaluate a seemingly infiniteing is finding and identifying aestivum L.). array of pink stains beforenoxious weed seed contami-Each of the nine seeddeciding whether a seed isnation. If a regulatory inspec-samples was divided intoalive and respiring or dead. tion identifies a seed sample 13 subsamples according toThere are specific guide- and finds a seed listed on a AOSA Seed Testing rules.lines in AOSA rules aboutNoxious Weed List, a stop-Samples sent for testing wereplant and root structures andsale order may be placed on spiked with a known quan- what constitutes normal andthe entire lot.tity of selected weed seedsabnormal plants, says Goltz.From a regulatory per-and other crop seed contami- And yet, some of these testingspective, identifying nox-nants. One subsample of eachcompanies are consistentlyious weeds is extremely species, held for future refer- giving higher germinationimportant, says Thiede. In ence, was carefully examinedscores for samples with dor- our efforts to keep palmer JUNE 2021SEEDWORLD.COM /45'