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Silverleaf Nightshade

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Botanical Name: Solanum elaeagnifolium
Other Common Names:

Declarations

 
Class Regions
Class 4Bland Shire Council,Cabonne Council,Castlereagh Macquarie County Council,Cootamundra Shire Council,Cowra Council,Dubbo City Council,Forbes Shire Council,Lachlan Shire Council,Mid-Western Regional Council,Narromine Shire Council,NSW DPI - Lands - Far West Region,Orange City Council,Parkes Shire Council,Upper Macquarie County Council,Weddin Shire Council,Wellington Council
Landholder Responsibilities: Growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority and the plant may not be sold, propagated or knowingly distributed
Why Is It Bad?: Silverleaf Nightshade competes strongly with crops and natural pastures. It significantly affects summer broadleaf crops, reducing yields. It also causes yield losses in winter crops as Silverleaf Nightshade depletes soil nutrients levels over summer. Increased stock losses as consumption of Silverleaf Nightshade can cause health problems in horses or cattle. Decreases in biodiversity, especially on roadsides, as Silverleaf Nightshade is a vigorous competitor. Increases in infestation sizes and distributions as Silverleaf Nightshade spreads quickly, especially after cultivation or grading.

Identification

Habit: Herb
Leaves: Leaves are lanceolate or oblong with scalloped edges, 2.5-10cm long and 1-3cm wide. They are silvery-green with a paler underside. Leaves and stems are hoary, giving a silvery-white appearance.
Flowers: Flowers are usually blue but can also be white, pink or purple. They have 5 petals and generally 25mm in diameter.
Fruit: Fruit are green-striped when young, maturing into an orange-brown berry. The berries are smooth, 8-14mm in diameter and can contain more than 100 seeds. A single plant can produce over 6000 seeds per season, and seeds can remain viable in the soil for more than 5 years.
Roots: Roots form a spreading perennial rhizomatous system that extends more than 2m into the soil profile.

Control Methods

Manual Removal: All parts of the plant must be removed as regrowth occurs easily from fragmented rhizomes
Chemical Use: Chemical application should occur when plants are fresh after rainfall. Stressed or dormant plants will not take in chemical. Various chemicals can be used during the plants life cycle that variously exhaust nutrient stores, prevent seed set, and kill root systems. Anecdotal evidence suggests more effective chemical uptake is achieved if herbicides are applied to the underside of leaves.
Fire:
Slashing & Cutting: Slashing has no affect as Silverleaf Nightshade readily regrows from basal stems.
Biological Control:
Grazing: Should be avoided as stock easily spread seed as well as suffer from the chemical content in Silverleaf Nightshade.
Cultivation & Scalping: Should also be avoided as machinery distributes root fragments over vast areas increasing infestation sizes. Good crop maintenance and use of in-crop herbicides will suppress Silverleaf Nightshade. Use of residual herbicides in winter (Eg atrazine or picloram) can reduce seedling and sucker regrowth in spring.
Smothering:
Solarisation:
Competition: Maintain competition levels in pastures. Lucerne or perennial grasses can suppress seedling and sucker emergence.
Monitoring: Successful treatment programs rely on ongoing monitoring of sites. Regrowth and new seedlings can easily become larger infestations if follow-up treatments are not part of the management program.

Images

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Image Credit: Megan Power


Image Credit: Megan Power


Image Credit: Megan Power


Image Credit: Megan Power


Image Credit: Megan Power





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