Read time: 5 minutes

Alternative second knock herbicides for broadleaf weeds in fallow

The sequential application of two separate herbicide treatments has become the most common ‘double knock’ approach used in weed management. Unfortunately, these approaches have added cost, complexity and scheduling issues to weed management programs but have been required for two main reasons:

1. To control herbicide-resistant weed populations, that may have been selected by prolonged use of a similar mode of action chemistry; and

2. Control of weed species or stages that are unsuccessfully controlled with single herbicide applications.

Paraquat has been the key active ingredient used in the second knock situation and can provide effective management of a wide range of grass and broadleaf weeds. However, it is clear we require other options to use in this management window to:

1. Avoid the more rapid selection of paraquat resistance; and

2. Provide options that may improve weed control in situations where paraquat efficacy is not adequate.

Since winter 2016, NGA has been screening a range of herbicides, to identify options that have the potential for this usage pattern. The two key broadleaf weeds being targeted are common sowthistle (Sonchus oleraceus) and flaxleaf fleabane (Conyza bonariensis).

DOWNLOAD FACTSHEET

Related Articles

Related Articles

View all
Article
News

WeedSmart Week goes to Mildura, Victoria

Growers and agronomists are invited to attend WeedSmart Week in Mildura, Vic from 30 Aug to 1 Sept. Grab yourself an early bird ticket! Read More...
Article
News

Maximising the benefits of new pre-em chemistry

New pre-emergent herbicides on the market give growers more options for mixing and rotating modes of action. Read More...
Article
News

Tickle those weeds this autumn

In an otherwise no-till farming system, using a skim plough, harrow, rake or disc chain implement to disturb the top few centimetres of soil can stimulate an even germination of weeds that can then be controlled prior to planting the crop. Read More...

Webinars

View all
Video
Webinar

First cases of glyphosate and paraquat resistant ryegrass in WA

For the first time in Western Australia, annual ryegrass from a cropped paddock was found to be resistant to glyphosate and paraquat. Read More...
Video
Webinar

Precision weed control – where are we at?

Mark Saunders and Ben White (Kondinin Group) discuss the latest advances in spraying technology, green-on-green and green-on-brown camera developments, AI and robotics, drone and weed mapping, and targeted non-herbicide tools. Read More...
Video
Webinar

S-Metolachlor usage in the northern region

In this WeedSmart webinar, WeedSmart northern extension agronomist Paul McIntosh and Syngenta Field Biology Manager Rob Battaglia discuss how S-metolachlor works, its efficacy, and what potential resistance problems might be around the corner. Read More...

Videos

View all
Video
Webinar

First cases of glyphosate and paraquat resistant ryegrass in WA

For the first time in Western Australia, annual ryegrass from a cropped paddock was found to be resistant to glyphosate and paraquat. Read More...
Video
Webinar

Precision weed control – where are we at?

Mark Saunders and Ben White (Kondinin Group) discuss the latest advances in spraying technology, green-on-green and green-on-brown camera developments, AI and robotics, drone and weed mapping, and targeted non-herbicide tools. Read More...
Video
Webinar

S-Metolachlor usage in the northern region

In this WeedSmart webinar, WeedSmart northern extension agronomist Paul McIntosh and Syngenta Field Biology Manager Rob Battaglia discuss how S-metolachlor works, its efficacy, and what potential resistance problems might be around the corner. Read More...

Factsheets

View all
Fact Sheet

Integrated weed management – workshop handbook

GRDC has developed a workshop series to help farmers and agronomists develop weed management strategies for their farming systems. Read More...
Fact Sheet

Integrated weed management in Australian cropping systems

This manual provides information on the latest tools and techniques to help manage current weeds and weeds of emerging economic importance. Read More...
Fact Sheet

Farm Business Management Factsheet

...

Subscribe to the WeedSmart Newsletter