Field Guide 
Weed Management Silverleaf Nightshade
Silverleaf Nightshade (Solanum elaeagnifolium)
Crop Impacts: Tomato and cotton
About Silverleaf Nightshade:
Silverleaf Nightshade is a broadleaf, deep-rooted perennial that is quite competitive. When is has infested fields and pastures, it is competitive enough to lower crop yields. Silverleaf Nightshade is toxic to animals. If ingested by livestock, the toxics in the plant do not react well inside an animal, which in turn greatly affects their gastrointestinal tract.
Family: Potato family (Solanaceae)
Silverleaf Nightshade Scouting and Prevention:
A mature Silverleaf Nightshade plant stands from 1 to 3 feet tall and has lots of branches. The stems have prickles that are red to a tannish colour, producing young shoots that are a dull silver-gray colour. The leaves of Silverleaf Nightshade alternate along the stem from one another and are egg-shaped, each leaf being about 6 inches long with either coarsely lobed or wavy edges. With the dense mat of hair that covers the leaf, it gives the plant a dull silvery green to light yellowish-green colour. The flowers that Silverleaf Nightshade produces are light blue to deep violet with a yellow center. The flowers are about 20 to 30 mm in diameter and sit in clusters along the branches, with the older flowers sitting at the tip of the main stem. May to September is the time period Silverleaf Nightshade blooms. They also produce round berries that are greenish yellow to brownish orange in color and are about 8 to 15 mm in diameter.
Common locations
- - Pastures
- - Cultivated fields
- - Tomato fields
- - Cotton fields
Prevention
Prevention of Silverleaf Nightshade is less expensive and less time-consuming than trying to control it. The best way to prevent Silverleaf Nightshade from entering your pastures is to create a competitive canopy of desirable spring and summer plants to create a good cover. Make sure when you seed a new area that you do so with certified weed-free seeds. If there is an infested area on your property, be sure to drive around instead of through it. Make sure to give all equipment that has been in infested fields a good clean so that no seeds are transferred.
Silverleaf Nightshade Control:
Silverleaf Nightshade has a very durable root system and they can regenerate growth from their root fragments that are left behind. Continuous control is required when managing this particular weed. It has the ability to re-establish in areas that have been under control for many years.
Cultural Control
Cultural control methods can work with this plant if you make sure to get rid of all the rootstock. Hand pulling is the best option to manage Silverleaf Nightshade. Clipping or mowing this weed will only allow it to re-grow. Make sure to include summer cereal into your crop rotation due to the fact that they are tolerant to herbicides that need to be used on Silverleaf Nightshade. Winter cropping can be successful if you manage to keep Silverleaf Nightshade suppressed during the summer months.
Chemical Control
For herbicide control with crops, it can be done if you apply atrazine, 2,4-D or picloram in infested fields. If you plant canola fields that are tolerant to trianzine, it can allow for the use of atrazine in suppressing Silverleaf Nightshade. These herbicides are best applied after rain and not when the plant is under stress. The herbicides will have more effect after rain due to the fact that at this time the roots of the plants are taking in water, meaning they will also be taking in the herbicide.
Latin / Alternative Silverleaf Nightshade names:
- - Solanum elaeagnifolium
- - Purple nightshade
- - White horsenettle
- - Tomato weed
Additional Silverleaf Nightshade Resources
http://www.nwcb.wa.gov/detail.asp?weed=123
http://www.ipm.ucdavis.edu/PMG/WEEDS/silverleaf_nightshade.html
http://weeds.dpi.nsw.gov.au/Weeds/Details/126#control