With so many farmers dry seeding crops to maximise potential yield, the loss of key post emergent herbicides through resistance makes it is even more important that weed control is planned before seeding.

Unfortunately many growers are unknowingly spending tens of thousands of dollars on ineffective herbicides. Gut-feelings and wishful thinking are no substitute for hard data and sound analysis. 

This is no way to develop a weed management plan!

To put this in perspective the 2010 pre-harvest survey in Western Australia by AHRI showed that over 80% of wild radish plants tested were resistant to Group B SU’s, 50% to Group B ‘imis’, 50% to Group F, and 70% to 2,4-D. Also Group B and Group A ‘fops’ were virtually useless on most annual ryegrass populations and clethodim was failing at an alarming rate. Five years later, the situation is much worse.

AGRONOMO and Peter Boutsalis at Plant Science Consulting offer you the chance to beat the resistance challenge in 2016 by conducting weed seed testing for which herbicides still work! Combined AGRONOMO and Plant Science Consulting have 50 years of weed and herbicide resistance expertise.

Seed testing requires the collection of weed seed samples before harvest and mailed to the lab. Once received dormancy of the seed is broken and seedlings grown before spraying with the herbicides determined as relevant to your farming system. Level of susceptibility for each herbicide tested is then measured. Results are normally available in early March.

Seed testing is an effective for both pre-emergent (trifluralin, Sakura®, Boxer® Gold) and post emergent herbicides.

A range of packages are available. Packages start with DIY seed collection and submitting samples for testing with report showing the effective herbicides.

Premium packages includes on-farm consultation, seed collection, advice on herbicide selection for testing, susceptibility testing, and a detailed report and management plan for the next three to five years.

For more information on Herbicide Susceptibility Testing go to /herbicide-suscept-testing/

Or phone on (Western Standard Time)

Andrew Storrie 0428 423 577

The Australian Glyphosate Sustainability Group has now added a searchable database to there highly informative site.

You can can now search for glyphosate resistance by:

• species
• State
• Region

This will give growers, advisers and policy makers the ability to get a better idea of where glyphosate resistance is occuring and how many populations have been found.

Currently it is best viewed in Internet Explorer and Chrome.

A Great Southern (WA) vigneron, who was worried about his under-vine weed control, contacted me in early September. Sally Peltzer, DAFWA, and I paid him a visit to discuss the potential problem and to collect samples for testing.

For the past 20 years the vigneron had regularly used paraquat (L) under the vines rotated with glyphosate (M) and the occasional Basta® (N) application. As can be seen in the image the paraquat applied two weeks earlier has had little effect on the annual ryegrass.

Live samples were sent to Plant Science Consulting in South Australia to conduct Quicktests® to determine herbicide resistance status before the grass had set seed.

The results are back and yes the annual ryegrass is resistant to paraquat with a low level of glyphosate resistance in some plants. Seed will be harvested from test survivors for more detailed testing in 2014.

I am now discussing best management strategies now and the future with the vigneron.

This highlights the fact that rotating herbicide modes-of-action delays resistance and doesn’t prevent it. To prevent/manage herbicide resistance multiple tactics must be used in the ONE season to PREVENT SEED SET of any survivors.

Those vineyard managers and broadacre farmers rotating modes-of-action need to have a rethink of their weed management strategies.