Crop weeds: controlling small weeds

Page last updated: Thursday, 4 June 2020 - 11:20am

Please note: This content may be out of date and is currently under review.

In an integrated weed management program, control of weeds should occur in the fallow, pre-sowing, early post-emergent and in pasture phases. Weed control can be achieved through killing weeds (particularly seedlings) with cultivation, herbicides, targeted weed control in wide-row cropping, targeted control of small patches of weeds and biological control tactics.

Methods for killing weeds in target areas

This weed control tactic involves controlling weeds once they have germinated, either before the crop has been sown or when they are seedlings within the crop.


Fallow or pre-sowing cultivation can kill many weeds including herbicide resistant populations. Cultivation is useful as a ‘one-off’ tactic in reduced tillage or no-till operations, and can be used as a non-herbicide component of a ‘double knock’ system.


Herbicides continue to play a vital role in integrated weed management. Better knowledge of the mechanisms and activity of herbicides will improve the impact and sustainability of herbicides as a weed management tactic. Herbicides include non-selective, pre-emergent and selective post-emergent products.

Weed control in wide-row cropping

Wide row cropping allows targeted weed control within the crop, using non-selective herbicides, to overcome herbicide resistant wild radish and annual ryegrass populations. However, overuse of non-selective herbicides can lead to resistance in these products.

Spot spraying

Techniques like spot spraying, chipping, hand roguing and wiper technologies can be used to target new weed infestations where weeds occur in low numbers and localised eradication is possible. More information can be found at the Herbicide application page.

Biological control

Biological control is the management of weeds using the weed's natural enemies (biological control agents). There are three generally recognised types of biological control: ‘classical’, ‘inundative’ and ‘conservation’.


Contact information


Sally Peltzer