Glyphosate resistance in ryegrass

The magnifying glass is put to glyphosate resistance in ryegrass in this webinar!

AHRI’s Peter Newman hosts the webinar with presenter Plant Science Consulting principle and University of Adelaide researcher, Dr Peter Boutsalis.

Peter helps us understand why plants surviving a glyphosate spray in the field aren’t always resistant.

Resources

• Plant Science Consulting (resistance testing)
• Article: Don’t jeopardise glyphosate for clean fencelines
• Australian Glyphosate Sustainability Working Group

Q & A Timestamps

22:06 I thought Dave Minkey did some work and showed 8L/ha of glyphosate didn’t kill ryegrass, but weren’t resistant, and it was due to the waxy leaf from early water stress?

23:36 Should we eradicate brome populations (glyphosate resistant brome populations) when we find them? (Taking a biosecurity approach and treating it like a noxious weed?) [AUDIENCE POLL]

28:03 What is the ideal water rate to spray glyphosate on ryegrass?

30:03 Does spray topping for seed set control of glyphosate resistant ryegrass or brome grass work considering that it’s sequestration at the tip e.g. does it go to the seed head?

31:52 Does dust from tractors in dry fallow neutralise glyphosate? E.g. for waxy leaves?

32:15 What about the use of adjuvants to improve the efficacy of glyphosate?

53:42 What is the optimum time to come back and double knock firebreaks?

56:37 In a Roundup Ready crop, would you prefer two applications of 1L/ha four weeks apart, or a single application of 2L/ha?

57:42 Spraying glyphosate at night in the cool verses spraying during the day?

58:54 Alliance (paraquat and amitrole) being good on fencelines?

59:49 On the label for UltraMax it talks about using a coarse to very coarse spray quality. Are coarse droplets too big to hit small ryegrass?