Machinery pathway: what is on your vehicle?
In Victoria (Australia), 35 vehicles and machines were cleaned and assessed for weed contamination: 18 utility and 4x4 vehicles, and 17 agricultural machines. The utility vehicles were mainly from local and state government organizations (except for 3 vehicles belonging to private contractors). All vehicles were exposed in their daily business to weed propagules. When collected, samples were visually assessed, spread over trays, and watered so that contaminating seeds could germinate.
More than 130 species were identified. Fourteen of these were declared noxious weeds in Victoria and 6 were regionally prohibited. The highest number of species found on a single vehicle was 38. No vehicles were free from contaminants. Poaceae, Asteraceae and Fabaceae were the most commonly represented families.
The most frequently found species or genus are listed in the table below, with their family, origin, and status in the Global Compendium of Weeds (GCW) which indicates their invasive behaviour elsewhere in the world, as well as the number of occurrences observed on vehicles and machinery.
|
Species
|
Family
|
Origin
|
GCW Status*
|
Vehi.
|
Mach.
|
|
Bromus catharticus
|
Poaceae
|
Americas
|
W, EW
|
4
|
6
|
|
Cenchrus spp.
|
Poaceae
|
;
|
W, QW
|
1
|
0
|
|
Centaurea calcitrapa
|
Asteraceae
|
Medit., W-As.
|
W, NW, GE, EW
|
1
|
0
|
|
Cirsium vulgare
|
Asteraceae
|
Euras.
|
W, NW, EW
|
2
|
0
|
|
Conium maculatum
|
Apiaceae
|
Europe
|
W, QW, NW, GE, EW
|
0
|
1
|
|
Crassula sp.
|
Crassulaceae
|
;
|
W
|
6
|
6
|
|
Dittrichia graveolens
|
Asteraceae
|
Medit., Middle East
|
W, NW, EW
|
2
|
0
|
|
Foeniculum vulgare
|
Apiaceae
|
Medit.
|
W, NW, GE, EW
|
0
|
1
|
|
Hordeum sp.
|
Poaceae
|
;
|
W, EW
|
6
|
3
|
|
Juncus acutus
|
Juncaceae
|
?
|
W, NW, Nat W, EW
|
0
|
1
|
|
Juncus bufonius
|
Juncaceae
|
Cosm.
|
W, EW
|
7
|
8
|
|
Lolium sp.
|
Poaceae
|
;
|
W, EW
|
7
|
8
|
|
Marrubium vulgare
|
Lamiaceae
|
Euras., N-Af.
|
W, QW, NW, GE, EW
|
1
|
0
|
|
Medicago sp.
|
Fabaceae
|
;
|
W
|
5
|
7
|
|
Nassella neesiana
|
Poaceae
|
S-Am.
|
W, QW, NW, EW
|
1
|
1
|
|
Oxalis pes-caprae
|
Oxalidaceae
|
S-Af.
|
W, NW, NatW, GE, EW
|
0
|
2
|
|
Pennisetum macrourum
|
Poaceae
|
S-Af.
|
W, QW, NW, GE, EW
|
1
|
0
|
|
Phalaris sp.
|
Poaceae
|
;
|
W, NW
|
7
|
8
|
|
Plantago coronopus
|
Plantaginaceae
|
Eurasia
|
W, GE, EW
|
4
|
10
|
|
Plantago lanceolata
|
Plantaginaceae
|
Eurasia
|
W, NW, GE, EW
|
2
|
8
|
|
Poa annua
|
Poaceae
|
Eurasia
|
W, NW, GE, EW
|
4
|
8
|
|
Polygonum sp.
|
Polygonaceae
|
;
|
W, QW
|
4
|
10
|
|
Rumex sp.
|
Polygonaceae
|
;
|
W, NW, EW
|
4
|
9
|
|
Silybum marianum
|
Asteraceae
|
Eurasia
|
W, QW, NW, EW
|
1
|
0
|
|
Sonchus oleraceus
|
Asteraceae
|
Eurasia
|
W, NW, EW
|
5
|
5
|
|
Tribulus terrestris
|
Zygophyllaceae
|
Madagascar
|
W, NW, NatW
|
2
|
1
|
|
Trifolium sp.
|
Fabaceae
|
;
|
W, EW
|
6
|
5
|
|
Ulex europaeus
|
Fabaceae
|
Eurasia
|
W, QW, NW, GE, EW
|
1
|
0
|
|
Vulpia sp.
|
Poaceae
|
;
|
W
|
7
|
9
|
|
Xanthium spinosum
|
Asteraceae
|
Trop. Am.
|
W, QW, NW, EW
|
1
|
0
|
* Abbreviations for the Global Compendium of Weeds column:
W: weed; NW: noxious weed; NatW: native weed; QW: quarantine weed; GE: garden escape; EW: environmental weed.
Although the sample size was possibly too small to draft any broad conclusions, this study highlights the fact that vehicles and machinery can play an important role in weed dispersal. Thorough cleaning of vehicles would significantly reduce the risk of speading weeds.
Sources
Under Control - Pest Plant and Animal Management News n°32 (2005) Victorian Departments of Sustainability and Environment and Primary Industries in Australia. 15-17 p. www.dse.vic.gov.au/undercontrol