IT didn't take Trayning farmer Trevor Fowler long to search for a new strategy this year after confirming a suspicion he has harbored for a couple of years.
We're talking about weeds that won't die after a spray.
"Last year we had a few paddocks where calthrop looked dead and we thought we had done a good job with a Roundup, ester and garlon brew," he said.
"But coming into seeding some of the plants were still a bit supple and while it was okay to seed through during the day, the big issue was weeds not flowing through the bar at night because of moisture.
"Most of the summer grasses and melons were okay but calthrop caused the blocks.
"I don't know whether we're getting some tolerance, not only from calthrop but also rolly polly plants."
This year Trevor upped the rates of his brew to 1.75 litres a hectare for Roundup, 300mm/ha for ester and 170mm/ha for garlon along with some Ally.
"The summer spray was the least satisfying program I've ever done," Trevor said. "We were spraying healthy germinations in December with the balance after harvest in January.
"The stuff we sprayed early produced variable kills and in the last paddocks, the calthrop had run its course and we reckoned we had fried it because we had a hot spell in mid-December and we sprayed at night.
"But two inches of rain in January saw more calthrop germinations along with a few melons.
"It was then a question of what to do next.
"Do we re-spray with plants under stress from the previous spraying and go for a mechanical kill?
"We waited for another week to have another crack at spraying but by then it was a dry February.
"The option was then to buy a set of coulters and put them on the front of the seeding bar and hope they did the job during seeding but we knew that would not be a 100 per cent guarantee.
"We bought the coulters to cover our butt but we also purchased a 50 foot (15.2m) Grizzly offset plough from Ag Implements, Mukinbudin, to get as much done as possible pre-seeding, on the paddocks where we knew we would have problems."
Trevor started with the offsets on March 20 and is confident he will have cleaned up the targeted paddocks before seeding.
"It's a slow process," he said. "We've got 50 foot but we're travelling at 8.5km/h and we're slower than that in rocky country, so we don't damage the discs.
"We going in about three inches (75mm) to make sure we get a full cut out while keeping a reasonable angle.
"It's a bit of a learning curve to get the right angle because the more you close it up the more critical it is to keep the machine even to avoid ridging.
"We opted for the fluted discs because we can get more purchases on the vines and they are a bit more self-cleaning.
"They are made in France and of a high tensile strength so theoretically they should last longer.
"They are easier to repair when they cop a real whack from a rock because they split vertically and you can run a bead of weld over it."
According to Trevor, the Grizzly requires pulling power of about 260kW (350hp) with fuel recorded at 55L/hr.
"We're happy with that and we get a working rate of 13ha/hr while we're going so we're averaging between four and five litres a hectare of fuel consumption."
Now he has the Grizzly, Trevor says he has another tool in the toolbox if he wants to introduce a green manuring paddock or to incorporate lime.
On the latter subject, he has some paddocks that have been limed multiple times, over the last 25 years, yet the soil pH is not increasing at depth as much as he would like.
"Maybe incorporation will help in that regard," he said.