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)
2)
Species and numbers of propagules arriving in Alaska 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
AK Feed
X
X
X
AK G&P
X
X
X
X
X
Coldspot
Perennial Rye
Grass Mix X
X
X
Denali Seed
X
DF Marks
X
Holm Town
X
Irwin & Son
X
Landmark Seed
X
X
X
X
X X
Lilly Miller
X
Mountain View Seeds
X
Pennington
X
X X
X
X
Scotts
X
Sun Mountain
X
Turf Seed Inc.
X
Number of Exotic Plant Seeds Per Pound of Grass Seed (n=97) Number of Seeds Per Pound
12000 10000 8000 6000 ― Mean=525 8 samples with value 0
4000 2000 0
Samples
Number of Exotic Species in Grass Seed Samples (n=97) 20
Number of Species
18 16 14 12 10 ― Mean=3.57 8 samples with value 0
8 6 4 2 0
Samples
23 Notable Exotic Taxa Found in Grass Seed (158 taxa total) Scientific Name
Common Name
Scientific Name
Common Name
Amaranthus retroflexus
redroot pigweed
Persicaria pensylvanicum
Pennsylvania smartweed
Avena fatua
wild oat
Phalaris arundinacea
reed canarygrass
Bromus tectorum
downy brome
Rumex acetosella
sheep sorrel
Chenopodium album
lambsquarters
Silene spp
catchfly
Cirsium arvense
Canada thistle
Solanum villosum
hairy nightshade
Crepis spp.
hawkbeard
Sonchus asper
spiny sowthistle
Elytriga repens
quackgrass
Sonchus oleraceus
common sowthistle
Galium spp.
bedstraw
Spergula arvensis
corn spurry
Hieracium spp.
hawkweed
Stellaria media
common chickweed
Lythrium hyssopiflora
Hyssop loosestrife
Taraxucum officinale
common dandelion
Melilotus spp.
sweetclover
Thlaspi arvense
field pennycress
Persicaria maculosa
ladysthumb
Crop Seed Sources Broker
Clovers
Cereals
Pasture Grass
Alaska Garden and Pet DF Marks
X X
X
X
Holm Town Nursery
X
Number of Exotic Plant Seeds Per Pound of Cropseed (n=18) Number of Seeds Per Pound
10000 9000 8000 7000 6000 5000 ― Mean=1950 1 sample with value 0
4000 3000 2000 1000 0
Samples
Number of Exotic Species in Crop Seed Samples (n=18) 20
Number of Species
18 16 14 12 ― Mean=6.28 1 sample with value 0
10 8 6 4 2 0
Samples
Notable Exotic Taxa Found in Crop Seed (63 taxa total) Scientific Name
Common Name
Scientific Name
Common Name
Amaranthus spp.
pigweed
Poa spp.
bluegrass
Bassia scoparia
kochia
Polygonum spp.
Brassica spp.
mustards/canola
knotweed/ bindweed
Chenopodium album
common lambsquarters
Rumex spp.
sorrels/docks
Silene alba
white cockle
Drachocephalum parviflorum
American dragonhead
Silene noctiflora
night-flowering catchfly
Galium spp
bedstraw/cleavers
hedge mustard
Lactuca serriola
prickly lettuce
Sisymbrium officinale
Lamium amplexicaule
henbit
Spergula arvensis
corn spurry
Stellaria media
common chickweed
Melilotus sp.
sweetclover
Thlaspi arvense
field pennycress
Persicaria maculosa
ladysthumb
Vicia spp.
vetch
Plantago spp.
plantain
Bird Seed Sources Broker
Sunflower
Corn
Safflower Nyjer
3-D Pet Food AK Garden & Pet
X
Anderson Feed
X
Animal Supply Co
X
X
Non-finch Finch Mix Mix X
X
X
X
X
X
X
X
Denali Seed Co.
X
DF Marks
X
Gutwein & Co
X
Imports Sterilization
X
Kaytee
X
Marks & Greger
X
X
Bird Seed Sources Broker
Sunflower
Corn
Safflower Nyjer
Mills Brothers
Non-finch Finch Mix Mix X
Modi Packaging
X
Natures Nuts
X
Natures Song
X
X X
X
ETO Sterilization
X
X
X
Pennington
X
X
X
X
X
Red River Commodity
X
X
X
X
X
X
X
X
X
Seawest Premium Harvest Wagners Will Henry’s Farm
X
X
X
X
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
a b
Notable Exotic Taxa in Bird Seed (170 total exotic taxa) Scientific Name
