NORTH Coast farmers, Susan and Dr Wayne Sommerville, say a lot of farming land in the region was going to waste because of weeds but their controls needed innovative thinking.
The couple have pioneered cutting-edge techniques for controlling lantana and advanced knowledge of biological control agents for the likes of crofton weed and giant Parramatta grass.
Now they are even using sheep - an unusual sight in the Northern Rivers - to keep fireweed in check.
The Sommervilles grow out weaners at "Creek's Bend", Toonumbar, west of Kyogle, on 480 hectares bordered by national parks, some of it world-heritage listed, and state forests.
Three-quarters is native forest, all fenced off, and the rest alluvial soil creek flats of native pastures with kikuyu and some paddocks improved to Rhodes grass and seteria.
In the late 1990s, the Somervilles became aware of the invasion of lantana and the spread of dying eucalypts in their forested country.
They were one of the first to raise the alarm bells about the ecological crisis now referred to as bell miner associated dieback, listed as a threatening process under the NSW Threatened Species Conservation Act.
The lantana provided habitat and protection from predators for the bell miner, a native bird, which then dominated other fauna and had eating habits that lead to the destruction of eucalypts, the Somervilles explained.
"Hectares upon hectares of ironbark and blue gum were lost across the region - we could see it moving through the landscape," Mrs Somerville said.
"We had to control the lantana, which seemed an impossible job. The country is too steep for tractors and aerial spraying is out because so much other flora and fauna would be affected."
While bush regeneration and protecting biodiversity was the main driving force for the Somervilles, the lantana was moving into productive country and would eventually have rendered beef production impossible.
The solution came in the form of modification of splatter gun technology to be effective on a large scale, developed in conjunction with ecologist John Hunter.
The couple tweaked the use of gas-powered handguns to apply large droplets of high concentrate glyphosate across lantana hedges every few metres.
It was a method that minimised collateral damage, herbicide run-off and the use of heavy equipment and was cost-effective.
It has since been refined to reduce the concentration of glyphosate and to make use of a four-wheel-drive to rapidly treat large areas.
The initial knockdown of lantana across more than 300ha at "Creek's Bend" was completed last year and follow-ups in the next few years should see the restoration of stable, healthy forest across the property.
But the bigger action has been the take-up of the techniques in national parks and state forests, where the control of lantana and replanting of natives has seen hundreds of hectares of forest regenerated.
"We also see it as part of our custodianship of the land to look after the forests," Mrs Somerville said.
Their work has set the foundations for successful bush regeneration across large parts of public forests and private land in the region and in 2013 won Mrs Somerville the Northern Rivers Landcarer of the Year award.
They are also using biological control agents against crofton weed, which is beginning to show some success.
Weed warriors at Toonumbar
BIOLOGICAL controls are playing a significant role in the weed battle at the property Dr Wayne Somerville and his wife Susan own, "Creek Bend", at Toonumbar in northern NSW.
In April, the couple introduced a new biological control agent for the crofton weed - a rust fungus called Baeodromus eupatorii, originating in Mexico.
CSIRO has investigated and tested the rust fungus and this year released it at several strategic locations across NSW, including "Creek's Bend".
It infects young leaves and stems of crofton weed and has great potential to reduce competitiveness, reproduction and spread of the weed, said the CSIRO's Dr Louise Morin.
Dr Somerville said it was early days, but the fungus rust had spread 100 metres and was stopping the flowering of crofton weed.
The Somervilles also, two years ago, introduced giant Parramatta grass plants infected with the crown rot Nigrospora oryzae.
"Most plants here are now infected and we are gradually shrinking the tussock sizes," Dr Somerville said.
Fireweed is their next target and they use the self-shedding Dorper sheep to that end.
Shan Goodwin
Journalist for The Land on the North Coast.
Journalist for The Land on the North Coast.
