By MEGAN CECHNER
IT will be a tightrope for some growers this season where post-emergent weed control could come at the cost of yield.
For areas of the northern Wheatbelt, it is a unique occurrence where crops are well out in front of the weeds, however this could cause problems with post-emergent applications.
Based in Geraldton, Farmanco consultant Bill Campbell said the wet start meant there was good activity from pre-emergent applications targeting wild radish, ryegrass and brome grass.
He said growers around Dalwallinu had already begun their post-emergent applications, while northern Wheatbelt growers were holding off.
"The pre-emergent herbicides have done a really good job at keeping weeds at bay and the crops are well out ahead of the weeds," he said.
"However, the rains we've had in the last 10 days means that there will be a flush come through."
Mr Campbell said this was likely to cause issues in Triazine Tolerant (TT) and Roundup Ready (RR) canola varieties where late post-emergent applications could have an impact on yield.
"We know that late applications of glyphosate can have a 10-15 per cent impact on yield in RR canola, so it is a tightrope trying to target weeds while reducing any impact on yield.
"TT canola could have similar problems with late applications of clethodim.
"It's a really good scenario in terms of crop growth, but where there are tight application windows for some herbicides in particular crops, growers will need to keep a close eye on things."
Further south, Landmark Hyden agronomist Kirsty Smith said some growers had already kicked off their spray programs in early lupins and cereals, but most were getting underway later this week.
Ms Smith said pre-emergent herbicides applications had been very effective and canola was well advanced around the area.
Cereal crops were well away but were now seeing some competition from wild radish.
She said diflufenican herbicides were in demand to control emerging broadleaf weeds.
"Jaguar herbicide has been a popular choice for those tackling heavier radish, while a Tigrex mix will be the mainstay for most," she said.