quantifying and identifying weed seed ... notable exotic taxa found in grass seed (158 taxa total)...

QUANTIFYING AND IDENTIFYING WEED SEED CONTAMINANTS IN CROP SEED, GRASS SEED, WILDFLOWER MIXES, AND BIRD SEED

Jeffery S. Conn USDA-ARS Fairbanks, Alaska

Acknowledgements

  Nan Werdin – Pfisterer, USDA-ARS   Gretchen Garcia, USDA-ARS   Jamie Martin, USDA-ARS   Washington State Seed Lab

USDA Disclaimer Mention of a trademark, proprietary product, or vendor does not constitute a guarantee of warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products or vendors that may also be suitable.

Increasing Rate of Exotic plant Taxa in Alaska (Carlson and Shephard 2007)

How Do New Plant Species Reach Alaska?

  Ornamentals   Hay/Straw   Crop/Reveg Seed   Bird Seed   Autos/RVs   Equipment   Migrating birds   Clothing/outdoor gear

  Boats   Float planes   Soil mixes   Wind

Goal: Determine Size of Pathways

How many propagules arrive via each pathway?

Importance of Knowing Pathway Size

  Focus detection efforts   Focus Research on

Mitigation Strategies   Agencies & legislature

can prioritize which pathways to “cork” first

Why Studying Pathways and Prevention is Important to Alaska

  Pristine ecosystems   Increasing

temperatures   Relatively few invasive

species now   Low cost for

prevention VS control   Few border crossings

and ports make it feasible

Weed Propagules from Crop, Grass, Bird Seed and Wildflower Mixes

Determine:

1)  Species and numbers of propagules arriving in Alaska

2)  If type of seed or seed broker are predictors of number of propagules arriving

Methods

  Surveyed stores and nurseries to determine  Types of seed sold  Brokers of seed (suppliers)

  Bought crop, grass, bird seed and wildflower seed mixes from all major brokers

  Photographed seed bags and certification tags

  Sampled bags using Association of Official Seed Analysts (AOSA) guidelines

Methods

  Samples examined by Washington State Seed Lab (crop and weed exam)  Weed Contaminants listed with number of seed per pound

of sample   One-way ANOVA used to determine if number of weed

seeds/lb and number of species for grass seed and crop seed was influenced by seed type or broker.

  Two-way ANOVA used to examine whether the combined effects of Bird Seed Type and Broker influenced the number of seed or species of weed contaminants in bird seed.

Sampling with Trier

Size of trier and size and number of samples differ between:

1.  Crops 2.  Size of Bag

Bag Photos

Front of bag Seed tag

Seed Lab Report

Grass Seed Sources Broker Blue grass Fescue Annual Rye Perennial

Rye Grass Mix

AK Feed X X X X

AK G&P X X X X X

Coldspot X X

Denali Seed X

DF Marks X

Holm Town X X X X X

Irwin & Son X X

Landmark Seed

X

Lilly Miller X

Mountain View Seeds

X X

Pennington X X X X

Scotts X

Sun Mountain X

Turf Seed Inc. X

0

2000

4000

6000

8000

10000

12000

Num

ber

of S

eeds

Per

Pou

nd

Samples

Number of Exotic Plant Seeds Per Pound of Grass Seed (n=97)

―Mean=5258sampleswithvalue0

0

2

4

6

8

10

12

14

16

18

20

Num

ber

of S

peci

es

Samples

Number of Exotic Species in Grass Seed Samples (n=97)

―Mean=3.578sampleswithvalue0

23 Notable Exotic Taxa Found in Grass Seed (158 taxa total) Scientific Name Common Name

Amaranthus retroflexus redroot pigweed

Avena fatua wild oat

Bromus tectorum downy brome

Chenopodium album lambsquarters

Cirsium arvense Canada thistle

Crepis spp. hawkbeard

Elytriga repens quackgrass

Galium spp. bedstraw

Hieracium spp. hawkweed

Lythrium hyssopiflora Hyssop loosestrife

Melilotus spp. sweetclover

Persicaria maculosa ladysthumb

Scientific Name Common Name

Persicaria pensylvanicum

Pennsylvania smartweed

Phalaris arundinacea reed canarygrass

Rumex acetosella sheep sorrel

Silene spp catchfly

Solanum villosum hairy nightshade

Sonchus asper spiny sowthistle

Sonchus oleraceus common sowthistle

Spergula arvensis corn spurry

Stellaria media common chickweed

Taraxucum officinale common dandelion

Thlaspi arvense field pennycress

Crop Seed Sources

Broker Clovers Cereals Pasture Grass

Alaska Garden and Pet X X X DF Marks X

Holm Town Nursery X

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Num

ber

of S

eeds

Per

Pou

nd

Samples

Number of Exotic Plant Seeds Per Pound of Cropseed (n=18)

― Mean=1950 1 sample with value 0

0

2

4

6

8

10

12

14

16

18

20

Num

ber

of S

peci

es

Samples

Number of Exotic Species in Crop Seed Samples (n=18)

―Mean=6.281samplewithvalue0

Notable Exotic Taxa Found in Crop Seed (63 taxa total) Scientific Name Common Name

Amaranthus spp. pigweed

Bassia scoparia kochia

Brassica spp. mustards/canola

Chenopodium album common lambsquarters

Drachocephalum parviflorum

American dragonhead

Galium spp bedstraw/cleavers

Lactuca serriola prickly lettuce

Lamium amplexicaule henbit

Melilotus sp. sweetclover


Plantago spp. plantain


Poa spp. bluegrass

Polygonum spp. knotweed/ bindweed

Rumex spp. sorrels/docks

Silene alba white cockle

Silene noctiflora night-flowering catchfly

Sisymbrium officinale

hedge mustard




Vicia spp. vetch

Bird Seed Sources

Broker Sunflower Corn Safflower Nyjer Non-finch Mix

Finch Mix

3-D Pet Food X X

AK Garden & Pet X X X X

Anderson Feed X

Animal Supply Co X X X X X

Denali Seed Co. X

DF Marks X

Gutwein & Co X

Imports Sterilization

X

Kaytee X X

Marks & Greger X

Bird Seed Sources

Broker Sunflower Corn Safflower Nyjer Non-finch Mix

Finch Mix

Mills Brothers X

Modi Packaging X

Natures Nuts X X

Natures Song X X X X X

ETO Sterilization X

Pennington X X X X X

Red River Commodity

X X X X X

Seawest Premium Harvest

X X

Wagners X X X X X X

Will Henry’s Farm X

Bird Seed Ingredients List Does Not Include Weeds

Number of Weed Seed/lb in Types of Bird Seed

Weed Taxa in Types of Bird Seed

ac a

ab

Notable Exotic Taxa in Bird Seed (170 total exotic taxa) Scientific Name Common Name

Abutilon theophrasti velvetleaf

Amaranthus spp. pigweeds

Ambrosia artemesiifolia

ragweed

Argenone albiflora prickly poppy

Atropa belledona belladona

Avena fatua wild oat

Bassia scoparia kochia

Brassica spp. 4 mustard taxa

Bromus tectorum downy brome

Chenopodium alba common lanbsquarters


Cirsium vulgare bull thistle

Convolvulus arvensis

field bindweed

Cuscuta spp. dodder

Digitaria spp. crabgrass

Echinochloa crus-gali

barnyardgrass

Eragrostis cilianensis

stinkgrass

Fallopia convolvulus wild buckwheat

Hieracium spp. hawkweed

Melilotus spp. sweetclover

Notable Exotic Taxa in Bird Seed (170 total exotic taxa) Scientific Name Common Name

Panicum spp. witchgrass & millet

Persicaria maculosa landysthumb

Phalaris arundinacea

reed canarygrass

Plantago spp buckhorn and broadleaf plaintain

Polygonum spp. smartweed & knotweed

Rumex spp. sorrel/dock

Salsoa kali Russian thistle

Senecio vulgaris common groundsel

Setaria pumila yellow foxtail

Setaria viridis green foxtail


Sida spinosa prickly mallow

Sinapsis arvensis wild mustard

Sisymbrium altissium

tumble mustard

Solanum villosum hairy nightshade

Sonchus oleraceus common sowthistle


Striga spp. witchweed


Vicia spp. vetch

Xanthium spp. cocklebur

Wildflower Mix Sources

  Alaska Garden and Pet  Wildflower Mix  Custom Wildflower Mix

  Denali Seed Co.  Arctic Habitat Wild Garden  Arctic Summer Wild Garden

  Ferry Morse   Butterfly & Hummingbird Wildflower

Mix   Bird & Butterfly Wildflower Mix   Early Spring Wildflower Mix   Shadey Area Wildflower Mix

Wildflower Mix Seed Tag

Notable Exotic Contaminants in Wildflower Mixes (19 contaminant taxa total)


Amaranthus spp. pigweeds

Anthemis cotula dog fennel

Aquilegia chrysantha columbine

Capsella bursa-pastoris shepherd’s purse

Chenopodium album common lambsquarters

Leucanthemum bulgare oxe-eye daisy


Polygonum spp. smartweed


Thlapsi arvensis field pennycress

quantifying and identifying weed seed ... notable exotic taxa found in grass seed (158 taxa total)...

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