WEEDS such as heliotrope, melon, fat-hen and caltrope are flourishing across a wide area of southeast Australia thanks to summer rain.

And it has meant an explosion of interest in weed control, says Rutherglen's Tim McNamara.

    AT A GLANCE
  • Who: Tim McNamara
  • What: weed control
  • Why: interest rises
  • Where: Rutherglen, Victoria
  • Report: KIM WOODS

As a director of McNamara's Country Store, Tim is often the first port of call for farmers needing chemical advice.

Tim said glyphosate plus garlon and adjuvants would control heliotrope and melons.

He suggested using MCPA plus dicamba or Ally and adjuvants to selectively control weeds without removing grasses.

"Wireweed and Paterson's curse have become a real problem when sowing winter crops," Tim said.

"Some call wireweed poor man's lucerne, but it is a pain.

"Roundup, Ally and adjuvants are safe going into cereals but there may be short-term residual effects on young phalaris, legumes and canola.

"Dicamba, MCPA and adjuvants will leave grasses behind but have let us down on heliotrope (control)."

Silver grass, unpalatable to stock and a heavy seeder, can be controlled with simazine.

Speaking at a recent pasture-management seminar in Victoria's North East, Tim said the simazine should be applied during rain.

"A shower of rain will wash the chemical on to the root zone where silver grass thrives and off the desirable species," he said.

"If the silver grass is tall, Gramoxone can be added. Raptor, a Group B herbicide, can be used mid-season but beware of clover retardation.

"It is not suitable for capeweed and needs to be used with high volumes of water (100 litres/ha)."

"Ideally, Raptor can be used to clean up a paddock for a more-productive pasture the following year."

Tim said ridding pastures of silver grass would improve clover growth.

Sprayseed or Gramoxone can be used early in autumn weed-control programs for barley grass, he said.

This will also pick up small capeweed and erodium plants.

Tim also said the herbicides propaquizafop (Shogun), haloxyfop (Verdict) or Raptor could control barley grass before sowing pastures.

"Sorrel is becoming a big problem and is an indicator of poor soil pH and structure," he said.

"Dicamba applied before sowing will remove the sorrel. Raptor can be used to control onion grass while Sprayseed will remove wintergrass.

"Chickweed, a shallow-rooted plant, has become more prominent and we have had success with Tigrex applied early with good moisture."

Tim said it was important to plan ahead, reduce grass-seed set, remove broadleaf weeds and resow pastures where necessary.