Herbicide Resistance and Ryegrass Weed Management Dr Peter Boutsalis

In July 2024 PGG Wrightson, PGG Wrightson Seeds and Bayer invited Dr Peter Boutsalis, Director of Plant Science Consulting, to spend time in Canterbury to discuss Herbicide Resistance and Ryegrass Seed Management.

Through his work at Adelaide University, as Director of Plant Science Consulting, a company Peter set up many years ago to offer herbicide resistance testing to farmers throughout Australia, and by conducting resistance monitoring surveys for the GRDC, Peter has a wealth of experience covering many aspects of herbicide activity, weed control and herbicide resistance.

While in Canterbury Peter visited several farms to see firsthand the situation here in NZ and he gave a number of presentations to farmers and merchant agronomists. Knowing that not everyone would be able to attend these presentations Bayer arranged for Peter’s Ashburton presentation to be videoed.

In the video Peter discusses several interesting and important topics. Topics such as what is herbicide resistance and why does it occur, why are pre-emergence herbicides such as Sakura so effective and important for ryegrass control, why is ryegrass so adept at overcoming herbicides and how to get the best from Roundup UltraMax.

Listen to the video in its entirety here or drop in and out as time allows. Whatever way suits, listen, enjoy and absorb what Peter has to say.

Topics

0:00 Introduction
4:41 Outlining the Australian resistance situation
8:31 Is it herbicide resistance or an herbicide failure
10:27 Global herbicide resistance - the current situation
12:58 History of arable cropping in Australia
16:03 Australian growers – their herbicide strategy
18:48 How widespread is herbicide resistance in Australia
25:07 Testing for ryegrass herbicide resistance in Canterbury, NZ
28:34 Pre-emergence herbicides - a powerful tool for ryegrass control
33:11 Weedsmart – the Big 6 Australian ryegrass control strategies
35:58 Herbicide resistance testing
45:24 The impact of grazing of ryegrass control
46:50 Why is ryegrass such a problem weed
57:12 Roundup UltraMAX – maximizing activity
1:06:28 Group 1 & group 2 herbicides – resistance and maximizing activity
1:12:37 Summary – key strategies to adopt