Monday, April 15, 2013

Blackberry Nightshade - Weed ID Photos

Blackberry Nightshade - Solanum nigrum

Blackberry Nightshade

Solanum nigrum

What is it?
Sometimes locally confused with ‘deadly nightshade’ which is in fact a different weed species.
What does it look like?
Growth: Bushy or herbaceous plant growing up to 1.25 m tall.
Flowers/Seedhead: Present throughout year. White, small, star-shaped flowers (often tinged with purple) and borne in small clusters in the leaf forks.
Fruit: The fruits are green, turning shiny black, toxic especially when immature.
When does it grow?
Annual or short-lived perennial: Blackberry nightshade emerges in autumn and winter and can last through summer to the following season and live as a perennial plant.  
Where does it grow?
Found in all horticultural districts.
Why is it a problem?
Competes vigorously for space and nutrients. Known to be host to numerous nematodes, fungi and viruses that are indirectly a threat to grapevines. Green fruit and leaves may at times contain toxic alkaloids which can contaminate grape harvest.
How does it spread?
Spread by seeds which are most often spread by birds and other animals that eat the fruit.
How is it controlled?
Biological control: No known biological control. Grazing is not recommended as fruit can be toxic to stock.
Physical Control: Cultivation and undervine mowing can be used to prevent seed production for several years but note blackberry nightshade has a tough woody stem and is best removed whole including the roots. When hand pulling remove from the vineyard if in flower. 
Conventional Control: Blackberry nightshade is susceptible to herbicide control by has a waxy leaf and a thick stem that prevents herbicide uptake. Herbicide performance is increased with the use of a penetrant adjuvant.
How do I find out more?

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