13 October 1995

Weed sprays now, maize men urged

MAIZE growers seeking good weed control in next years crop should act now to apply Roundup while couch grass is still growing.

So says Maize Growers Association agronomist Simon Draper, who warns that couch grass, and thistles, are becoming an increasing problem on land used to grow continuous maize. Both weeds used to be controlled by Atrazine. But at the reduced rate now cleared for use (3 litres/ha) little control will be achieved.

"The only chance to control these weeds is in the stubble before next years maize crop," he says.

For those who harvested maize about two weeks ago, now will be an ideal time to spray, with fields starting to green up earlier than normal due to the early harvest.

To achieve good control it is necessary to spray when the weeds are growing actively and the Roundup should be left undisturbed on the weeds for a minimum of seven days.

to ensure maximum penetration into the plant, says Monsanto. It recommends spraying once the couch grass has three to four leaves or is 150mm (6in), and before the weather gets too cold, and suggests an application rate of 3-4 litres/ha.