2019 Rule Change Proposal 12

Purpose of Proposal: To add Madia gracilis, grassy tarweed or slender tarweed to Volume 1, Table 2A and to Volume 3 of the AOSA Rules.

Present Rule: None

Proposed Rule:

Volume 1. Principles and Procedures

Table 2A. Weights for working samples. Minimum Minimum Approximate Approximate weight for Pure weight for number of number of noxious-weed Seed Chaffy purity seeds per seeds per a Kind of seed seed or bulk Unit Seed analysisb gramc ounced # examination Grams Grams Number Number Madia gracilis (Sm.) D. D. Keck 27 4 40 657 18,616 grassy tarweed, slender tarweed

Volume 3. Uniform Classification of Weed and Crop Seeds

CONTAMINATING Nomen Spp Scientific name Common name Family CLASSIFICATION # class A F H R S T V Madia gracilis (Sm.) D. D. grassy tarweed; 457482 Asteraceae F, R W C W C W W W Keck slender tarweed

Harmonization and Impact Statement: Madia gracillis is not in the Federal Seed Act Regulations, the Canadian M & P, or the ISTA Rules. This is a commercially marketed species; therefore, adding working weights and a pure seed unit definition to the AOSA Rules will standardize seed testing procedures among laboratories. This species is not listed in Volume 3 Uniform Classification of Weed and Crop.

Supporting Evidence: Madia gracilis is a native annual found in many habitats from Baja California north through the Pacific coast states and British Columbia and east to Utah and Montana. Plants range from 6- 100 cm tall, the head inflorescence consists of both ray and disc flowers. Fruits of ray flowers are 3.2-4 mm long and 1.5-1.8 mm wide, laterally compressed, +/- 3-sided, club-shaped, +/- arched, usually beakless and lacking pappus, glabrous, black, purple or mottled, and dull; fruits of disc flowers are similar (Figure 1). This species attracts many native pollinators and other beneficial insects and the seeds provide a food source for wildlife. This native plant is used by various conservation programs and is sold commercially in roadside revegetation mixes and for use in pollinator hedgerows along the edges of agricultural fields.

Figure 1. Madia gracilis fruits. Photo by Tanya Harvey http://westerncascades.com/photos/seeds/seeds-i-o/

Seed counts were conducted at the Agri Seed Testing Lab on six seed lots received since 2008. The seed count method was in accordance to AOSA Rules, Section 13: Non-mechanical Seed Count and Working Weight Determinations (Figure 2). Refer to Appendix 1 of this proposal for replicate data.

Purity Working Weight for Madia gracilis 5 4.5 4 3.5 3 2.5 2 1.5 PurityWeights (g) 1 0.5 0 0 1 2 3 4 5 6 Lot Number

Figure 2. Purity working weights for six commercial seed lots of Madia gracilis, grassy tarweed or slender tarweed, based on non-mechanical seed counts. The red line indicates the average purity working sample weight across all six seed lots is 3.902 grams.

Results of statistical analysis are shown in Table 1. Methodology for the analysis: 1. Each set of data per seed lot (usually 8 replications) was checked for normality of distribution (Shapiro-Wilk test for normality, p  0.05; ranks not averaged for tied values). 2. For non-normally distributed data sets of a single seed lot, an outlier test was used to identify a single outlier (Grubbs’ test, p  0.05). 3. Data was rechecked after removing a single outlier. Revised data sets (after removing the outlier) were used in the final determination of average weight of 100 seeds. If removing a single outlier still resulted in non-normally distributed data, the data set for that seed lot was considered unreliable and results excluded from further data analysis. 4. Means of each lot were then used to calculate the overall mean weight of 100 seeds for that species and a 95% confidence interval for the mean. 5. The same means were also checked for normality of distribution and presence of outliers. However, no attempt was made to discard outliers at this stage. If the outlier replicate average can be ascribed to errors in data collection, then the data should be discarded. However, if the outlier is due to natural variation (e.g., genetic, varietal or cultural differences), discarding the data is not recommended. This is a judgment call unrelated to statistical analysis results.

Table 1. Species mean seed weight and confidence intervals of data checked for normality of distribution and presence of outliers.

Results of Results Single No. revised lots Mean wt. normally outlier Standard Species of normally of 100 CI (95%) for mean distributed removed error lots1 distributed seeds (Y/N) 2 (Y/N) 3 (Y/N) 4 Madia gracilis 6 Y 0.1561 0.0104 0.1293-0.1829 1Original number of tested lots. 2 Shapiro-Wilk test for normality (p  0.05). Normality test separately applied to replication data of each seed lot. 3 If data set (replications) for a seed lot is not normally distributed, one outlier (replication) is removed. Presence of outliers verified using Grubbs’ test (p  0.05). 4 Each seed lot was tested for normality after outlier was removed. If data set of a seed lot was still not normally distributed after removing outlier, that seed lot was excluded from analysis.

References: Sources for general plant information provided above and additional information on this species can be found in the following references and websites:

Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken (Eds.). 2012. The Jepson manual: vascular plants of California. 2nd Ed. University of California Press.

Ross, T.C. 2012. Plant guide for grassy tarweed (Madia gracilis). USDA-Natural Resources Conservation Service, Plant Materials Center, Corvallis, OR. https://plants.usda.gov/plantguide/pdf/pg_magr3.pdf http://www.heritageseedlings.com/page_458_52/madia-gracilis https://plants.usda.gov/core/profile?symbol=magr3 https://www.pnwflowers.com/flower/madia-gracilis

Submitted by: Sharon Davidson, RST, Agri Seed Testing, Inc., 1930 Davcor ST SE, Salem, OR 97302 [email protected]; Deborah Meyer, Purity Subcommittee AOSA Co-chair, [email protected]; and Gil Waibel, Purity Subcommittee SCST Co-chair, [email protected]

The authors would like to thank Dr. Riad Baalbaki for performing the statistical analysis.

Date Submitted: October 15, 2018 Appendix 1 – Seed counts for Madia gracilis, grassy tarweed or slender tarweed

Replication Lot 1 Lot Lot 3 Lot 4 Lot 5 Lot 6 1 0.1120 0.1820 0.1710 0.1690 0.1290 0.1600 2 0.1270 0.1800 0.1640 0.1640 0.1300 0.1610 3 0.1230 0.1800 0.1650 0.1760 0.1270 0.1630 4 0.1150 0.1830 0.1760 0.1820 0.1330 0.1620 5 0.1210 0.1850 0.1710 0.1750 0.1360 0.1650 6 0.1200 0.1870 0.1800 0.1620 0.1270 0.1600 7 0.1120 0.1830 0.1670 0.1770 0.1300 0.1590 8 0.1210 0.1820 0.1730 0.1730 0.1310 0.1600 9 0.1150 x x x x x 10 0.1220 x x x x x 11 0.1230 x x x x x 12 0.1180 x x x x x 13 0.1120 x x x x x 14 0.1210 x x x x x 15 0.1210 x x x x x 16 0.1210 x x x x x Mean 0.119 0.18275 0.170875 0.17225 0.130375 0.16125 purity wt. 2.975 4.56875 4.271875 4.30625 3.259375 4.03125 nox wt. 29.75 45.6875 42.71875 43.0625 32.59375 40.3125 wt./seed 0.00119 0.001828 0.001709 0.001723 0.001304 0.001613 seeds/g 840 547 585 581 767 620 seeds/oz 23814 15507 16585 16471 21744 17577 seeds/lb 381024 248119 265356 263542 347911 281232 Mean weight of 100 seeds = 0.1561 grams Mean purity working weight across all seed lots = 3.902 grams Mean noxious working weight across all seed lots = 39.02 grams Mean weight per seed across all seed lots = 0.001561 gram Mean number of seeds per gram across all seed lots = 657 Mean number of seeds per ounce across all seed lots = 18,616 Mean number of seeds per pound across all seed lots = 297,864