Crop weeds: stop weed seed set

Page last updated: Wednesday, 17 February 2021 - 10:41am

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Preventing weed seed set provides an opportunity to control weed seed set in the pasture, late fallow, late stubble and in-crop phases. Weed seed set is prevented through techniques such as spray-topping with selective herbicides, crop-topping with non-selective herbicides, pasture spray-topping, crop dessication and windrowing, wiper technology, grazing, silage and hay-making and by renovation crops and pastures (such as brown manuring, mulching and hay freezing).

Management options for preventing weed seed-set

Pasture spray-topping

Pasture spray-topping is used to prevent the domination of annual weeds (predominantly grasses) in medium-term (phase) pasture systems.

Renovation crops and pastures

These include green manuring, brown manuring, mulching and hay freezing and can be used to return crops and pastures to the soil to improve soil fertility, reduce weed burdens and increase soil organic matter.

Silage and hay

Both silage and hay production of crops and pasture can reduce the seed set of target weeds and remove viable weed seeds.

In-crop weed management for seed set control

This includes spray-topping with selective and non-selective herbicides, dessication and windrowing (swathing) to minimise the replenishment of seedbanks and/or reduce grain contamination.


By actively managing weeds in pastures by varying grazing management techniques will maintain a balance of pasture species to maximise desirable legumes and grasses while keeping weed levels low.


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