Are you frustrated by summer weeds? We are too. They suck moisture and nutrients, can be hard to control, and usually reoccur if not managed properly.
Here’s a list of 13 of the common pesky suspects we find in our areas and what you can use to control them in your paddock.
** Just remember, this is based upon broadacre spraying situations, and these are rough guidelines. You should speak to your agronomist for a complete brew to knock out the weeds specific to your paddock and for relevant plant backs.
1. Blanket Weed
Also known as:
Twinning Toadflax
Height:
Can grow up to 1m in diameter.
Leaves:
Dense, hairy leaves, becoming smaller towards the ends of branches.
Flowers:
Pea like flowers with basal spur.
Control:
Good rates of Glyphosate or Ester with a Group 14 (G) spike and the addition of an oil to help get the actives onto the leaf surface.
2. Buckbush
Also known as:
Roly-Poly
Height:
Can grow upright or spreading, to 70cm high.
Leaves:
Generally hairless, rigid, cylindrical & linear, ending in a prickly point.
Flowers:
White, small and occur singularly in leaf axils.
Control:
Use good rates of Paraquat* (Gramoxone) (*requires S7 license) on small plants or high rates of Amine 625 with an oil on larger plants. The addition of Metsulfuron (Ally) will help with residual control.
Ensure coverage is excellent for larger weeds, slow down your ground speed and increase water rates.
3. Caltrop
Height:
Can grow up to 2m in diameter
Leaves:
Opposite, consisting of 4 to 8 pairs of oblong leaflets with a slightly pointed apex.
Flowers:
Bright yellow.
Control:
Glyphosate will work well on small plants with Metsulfuron to stop later germinations.
4. Clammy Goosefoot
Also known as:
Small Crumbweed or Mintweed
Height:
Can grow up to 50cm long
Leaves:
Alternate, oval, rounded apex, lobed, long petiole.
Flowers:
Very small, green clusters.
Control:
Glyphosate and/or a 2,4D product.
5. Fat Hen
Also known as:
Lamb Quarter
Height:
Can branch out to 1m.
Leaves:
Mealy white, roughly diamond shaped with wavy to toothed margins.
Flowers:
Mealy white flowers are clustered along branched spikes at the ends of branches.
Control:
Good rates of Glyphosate and/or Amicide with an oil.
6. Flaxleaf Fleabane
Height:
Can grow up to 70cm tall
Leaves:
Oval shaped with toothed margins.
Flowers:
Terminal, pyramid-shaped clusters with white to pale pink hairs.
Control:
Good rates of Glyphosate with the addition of Ester. Metsulfuron can help with seedlings coming up. Double knocking is critical with this weed. It is a hard one to control. In ideal conditions with small, freshly growing plants, adding a Group 14 herbicide will increase control.
7. Horehound
Height:
Can grow up to 80cm tall
Leaves:
Opposite, round to egg shaped, wrinkled, and covered with white hairs.
Flowers:
Small, white in dense many-flowered whorls in the leaf axils.
Control:
Good rates of Glyphosate with addition of Ester. Metsulfuron can help with seedlings coming up. Repeat applications may be needed as it is a hard one to control.
8. Marshmallow
Also known as:
Small Flowered Mallow
Height:
Can grow over 1m
Leaves:
Alternate with wrinkled, round with 5 to 7 broadly toothed lobes.
Flowers:
Clusters of 4/5 pink or white flowers
Control:
Good rates of Glyphosate with a Group 14 spike. Group 14’s (old Group G) are very strong on Marshmallow. With large plants, the addition of Ester will help improve control.
9. Melons
Pictures:
Top – Paddy Melon
Bottom – Afghan Melon
Photo: agric.wa.gov.au
Height:
Can grow to 2m or more in length
Leaves:
Large triangular, with a pointed apex, toothed and deeply lobed.
Flowers:
Yellow, Paddy melon flower covered in bristles.
Control:
Melons are best controlled with Triclopyr (Garlon). For afghan melons, Amine is a better mix partner than Ester.
10. Potato Weed
Also known as:
Common Heliotrope
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Height:
Can grow to 50cm high
Leaves:
Alternate with short hairs on both surfaces and egg-shaped.
Flowers:
White flowers
Control:
Good rates of Glyphosate or Paraquat on older stressed plants. We’re currently seeing that a spike of Terrad’or is smoking plants too.
11. Silverleaf Nightshade
Also known as:
Tomato Weed
Height:
Can grow to 40-60cm tall.
Leaves:
Silver-green spear-shaped, dense hair on both surfaces. Leaf margins are scalloped and undulating.
Flowers:
Blue-violet in colour with a bright yellow centre.
Control:
Good rates of Glyphosate and Ester with an oil. Tordon 75D & Starane are also effective.
12. Tomato Bush
Also known as:
Blackberry Nightshade
Height:
Can grow to 80cm tall.
Leaves:
Alternate, diamond-shaped, undulating margin, and short hairs on both surfaces.
Flowers:
Small white flowers with a yellow centre, which produces a green berry which turns black as it ripens.
Control:
Good rates of Ester or Amine or a mix of Ester and Glyphosate. Tordon 75D is also a good option.
13. Wireweed
Also known as:
Hogweed
Height:
Can grow up to 1m long stems.
Leaves:
Spear shaped
Flowers:
Small pink to white flowers formed in dense clusters at the base of leaves.
Control:
Mixes of good rates of Glyphosate and 2,4D with an addition of a Group 14 spike or a Dicamba. The addition of Metsulfuron can help with residual activity. Terrad’or looks to be doing an excellent job as a Group 14 spike at this stage. It can be a difficult weed to control.
BONUS Top tips:
Ester 680 will be a stronger alternative to Amine in most situations. However, the use of Ester may be restricted in your area depending on buffer zones and local off-target crops.
Mixes with Glyphosate will lose significant effectiveness when weeds are stressed, when a large amount of dust is present on plants, or throw up from sprayer tyres. In these situations switching to a Paraquat based brew may be more effective.
As a general rule of thumb, paraquat brews should be sprayed in low light evening conditions and glyphosate job earlier morning. But be careful using Group 4’s and 2,4-D at these times, and remember to stick to APVMA regulations when using these products.
If you want a more detailed overview of your pesky weed situation, give one of our agronomists a call.
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