Broad-leaved weed control

Key Points

  • High weed populations compete with the crop for water and nutrients
  • Weeds can harbour infestations of insect pests
  • Broad-leaved weed control programs begin in autumn
  • Follow-up treatments are normally applied by GS 30-32 of the crop

Introduction

wheat spraying cleavers


Control of broad-leaved weeds in cereals can be achieved using a number of different products from Dow AgroSciences Ireland.

Biology

Land used for cereal crops can become infested with annual and perennial weeds. To minimise competition between weeds and crop it is advisable to treat broad-leaved weeds in cereal crops before they compete significantly with the crop. Programs begin in the autumn, often with additional treatments made in the spring, around GS 30-32.

Boxer Pack

Typical Timing of Weed Emergence

Weed J F M A M J J A S O N D
Cleavers
Galium aparine
Charlock
Sinapis arvensis
Mayweed
Matricaria spp.
Common Poppy
Papaver rhoeas
Common Chickweed
Stellaria media
Redshank
Polygunum persicaria
Knotgrass
Polygunum aviculare
Common Speedwell
Veronica persica
Ivy-leaved Speedwell
Veronica hederaefolia
Groundsel
Senecio vulgaris
Field Pansy
Viola arvensis

Darker colour represents peak of emergence 

Another autumn option for Ireland growers of winter wheat, winter barley and winter oats is the application of Boxer*. Useful control of some key autumn-germinating weeds such as common chickweed, mayweed and volunteer oilseed rape can be achieved from applications as low as 75ml of product per hectare. Boxer is approved for use in the autumn once the crop has reached GS13.

Beginning in February broad-leaved weeds in cereals can be controlled with an application of Boxer up to 150ml per hectare. The total dose of Boxer applied to any cereal crop must not exceed 150ml per hectare. Spring applications of Boxer will control the following weeds:

Weed Controlled
(on product label)
Rate of Use
150ml/ha 100ml/ha 50ml/ha
Cleavers Up to 500mm 200mm –
Common chickweed – Flowering 6 true leaves
Hedge mustard – 100mm –
Scented mayweed – Flower buds visible Rosette stage
Scentless mayweed – Flower buds visible Rosette stage
Shepherd’s-purse – 100mm –
Volunteer oilseed rape – Before flower buds visible 4 true leaves
Wild radish (runch) – 100mm –

Based on commercial usage experience the following levels of control have been noted on weeds not mentioned on the Boxer label:

Non-label weed
Rate of Use
150ml/ha 100ml/ha 50ml/ha
Black-bindweed – 100mm –
Black nightshade – 50mm –
Charlock – Before flower buds visible 4 true leaves
Corn marigold – Up to rosette –
Clover – 100mm –
Forget-me-not – 100mm –
Groundsel Before flower buds visible 50mm –
Hemp nettle – 4 true leaves –
Parsley-piert – 100mm –
Shepherd's needle – 100mm –
Sowthistle (annual) – 100mm –
Thale cress – 6 true leaves –
Wild carrot – 6 true leaves –
Volunteer beans 200mm – –
Volunteer peas – 100mm –
Weed beet (from seed) – 6 true leaves –

Learn more about Boxer

As the season progresses even more options become available for broad-leaved weed control in cereals. Starane* XL can be applied once the crop has reached GS13.  Starane 2 can be used from late April onwards, when temperatures are warmer and the risk of night frosts has diminished.

Visit the product pages for more comprehensive information about Boxer, Starane XL, Galaxy, Broadway Star and Starane 2.