Silverleaf nightshade alert!

Based on the south-west slopes, Hilltops Council bio-security officers Tom Pickering and Ben Mott are urging farmers in their area to be on the look out for new and fresh emerging silverleaf nightshade (SLN) plants.

Mr Pickering said silverleaf nightshade (Solanum elaeagnifolium) is a weed of significance in NSW which reduces productivity in crop and pastures by taking out valuable moisture and nutrients.

"It's a long-lived perennial plant with a very deep root structure and grows from spring through to late autumn," he said.

"Spread is relatively slow but once established dense infestations are an ongoing annual burden."

The plant is a native of North and South America and was likely introduced in imported fodder during the Federation drought as it was first noticed at Bingara in 1901.

Since that time it has adapted to a wide range of environments with rainfall varying from 250mm - 600mm.

Mr Pickering noted it is important to have a long-term management plan to control the weed of significance.

"There is a minimum period of three to five years to control SLN with up to three or four sprays during the growing season," he said.

"New shoots emerge quickly after rain and the top of the plant needs to be continuously sprayed to exhaust the roots of their carbohydrates."

Mr Pickering pointed out seedlings can germinate from root fragments or berries and begin to emerge from late August.

"They flower very quickly and will set seed and berries from November until late March," he said.

"It is important once berries have set to try and reduce stock movement through infested paddocks as livestock and sheep in particular favour the berries and scientific studies have shown that the seed can stay in the digestive system for up to 31-58 days."

The registered chemicals for controlling SLN and used by Hilltops Council staff are Fluroxpyr (starane advance) or 2,4 -d with Picloram (Tordon 750) but advise is given to consult with an agronomist on application rates.