The black keeled slug is the most common slug found in areas where rainfall is more than 450mm annually. Photo: GRDC

INCREASED slug damage has been reported by grain growers in Victoria, South Australia and southern New South Wales after ongoing wet conditions.

Some areas have experienced this pest for the first time.

Slug expert Michael Nash said wet conditions last spring had extended the slug breeding period, resulting in higher numbers this season.

“This follows a run of dry years in some areas that aren’t used to seeing slugs as a threat,” Dr Nash said.

They include the Liverpool Plains of New South Wales, and the Victorian Wimmera.

“Growers have been caught off guard.”

To help growers manage the impact of slugs this season, the Grains Research and Development Corporation (GRDC) has updated a Slug Control Factsheet to assist with identifying, monitoring and controlling pest numbers to reduce crop losses.

GRDC will also be delivering a series of slug management workshops through this and next month.

Dr Nash said growers who hadn’t anticipated slugs and proactively implemented control measures, could have experienced high slug numbers damaging crops, and have had to resow.

“Crops are at their most vulnerable to slugs as seedlings, so growers need to protect the crop until it establishes, usually in the first four to eight weeks depending on ground temperatures,” Dr Nash said.

“Slugs emerge from the ground over an extended period of time, so growers need to have bait protecting seedlings during establishment, which means they may need multiple applications of bait.”

Dr Nash said an integrated pest-management approach was the most effective way to protect crops from slugs.

“No single method provides complete control, so growers need to use an integrated approach.

“This needs to include paddock monitoring, weather monitoring to identify risk, maintaining natural enemies and implementing cultural practices, such as establishing crops quickly to avoid emerging slugs, rolling immediately after sowing, then baiting as needed.”

To help growers understand how to better predict slug issues and implement integrated management strategies on-farm, GRDC series of slug workshops is as follows:

• Rutherglen, Vic: August 16, 8.30am-1pm;
• Yallunda Flat, SA: August 24, 7.30-10.30am;
• Gippsland, Vic: August 30, 7.30-10.30am;
• Rochester, Vic: September 1, 7.30-10.30am;
• Inverleigh, Vic: September 5, 7.30-10.30am;
• Derrinallum, Vic: September 6, 7.30-10.30am;
• Tabor, Vic: September 7, 7.30-10.30am;
• Naracoorte, SA: September 8, 7.30-10.30am;
• Millicent, SA: September 9, 7.30-10.30am;
• Hagley, Tas: September 21: 7.30-10.30am;
• Campbell Town, Tas: September 23, 7.30-10.30am.

Source: GRDC