No-till’s slug challenge

Slug damaged canola plants. Photo: Steve Hynes
Mapping slug numbers… would allow variable rate spreading
Slug damaged canola plants. Photo: Steve Hynes

NO-TILL farming systems have had a massive advantage for croppers in high rainfall zones but one thing that has been difficult to manage has been minimising slug damage.

The slugs have thrived in standing stubble situations, leading many farmers in areas such as Victoria’s Western District to revert to management options such as stubble burning.

Burning stubble can be damaging in other aspects of soil structure, but are regarded as a necessary evil in keeping ahead of the area’s cropping enemy No. 1 by some growers.

One researcher, VNTFA president Tim Pilkington, who is an agronomist in the Western District is attempting to find a solution to reducing slug numbers to tolerable numbers in no-till systems.

Much of the work centres around accurate application of bait at sowing time.

A key issue is getting sufficient bait to the slugs.

“Each slug needs a bait each, we’re working on using a combination of bait in the row and bait spreading to take out high populations,” Mr Pilkington said.

He said another focus was using high quality bait.

“It’s an expensive process, but if you get more slugs than effective baits you will struggle to cut numbers.”

Mr Pilkington said in his research he had worked on mapping slug numbers, which in turn would allow variable rate spreading which would lessen the use of expensive slug bait.

“At present it’s about getting that mapping to an economic level – we have mapped a hectare of slug numbers, but it took a lot of effort, so we would probably need to get a method to do that more efficiently on a larger scale.”