Tuesday, April 16, 2013

Marshmallow - Weed ID photos

Marshmallow - Causing you trouble? Contact DJ's for more information.



Marshmallow

Malva parviflora

What is it?
Marshmallow, Malva parviflora is an exotic annual weed that is active after autumn and winter rains.
What does it look like?
Leaves : Rounded and wrinkled, 17 – 100 mm in diameter, with prominent veins and have 5 – 7 shallow lobes, toothed margins, notched bases and are borne on green to purple/green stalks that are sometimes up to 24 cm long.
Growth: Woody with spreading and upright branches 30 - 100 cm high with stems covered in stiff hairs. Plants are initial semi-prostrate, but become more erect with maturity.
Flowers: Pale pink to white hibiscus-like flowers with five petals are 4 - 6 mm long, and are in small clusters of 2 - 5 in the leaf forks, on stalks 7 – 22 mm long.
Seed s: The seeds are red/brown and rounded, 1 – 2 mm in diameter.
When does it grow?
Winter Active: An annual weed that emerge after rainfall or irrigation in late autumn and winter. Plants grow quickly throughout winter and spring and flower during spring and summer (7 – 13 weeks after emergence).
Where does it grow?
Found in all districts of McLaren Vale.This plant is also widespread weed of wasteland, degraded pasture, roadsides, along watercourses and in gardens.
Why is it a problem?
Competes with grapevines for nutrients and It tolerates a wide range of herbicides including glyphosate and can be a host of many insects pests including light brown apple moth.
How does it spread?
Seed can be set within two weeks of flowering. April to November in SA.The seed has strong dormancy with very little fresh seed germinating, but only a short seed-bank life with only 25% of seed remaining viable after one year of burial and less than 12% after two years.
How is it controlled?
Biological Control: Vegetable weevil often decimates dense stands. Stock can also graze marshmallow.
Conventional Control: Manual removal, particularly whilst plants are young, is effective. Mulching is an excellent method to prevent germinating seeds from establishing. Cultivation may be useful as the plant’s shallow root system is easily dislodged from the soil and the plant quickly dries out in warm weather.
Herbicide Control: No known resistance to herbicide however weed populations can build up over several seasons. Marshmallow control has historically centred on Glyphosate and the addition of a spike product. These herbicides aid in the desiccation of the plant but are only completely successful on very small weeds.
How do I find out more?

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