Double breaks – a double shot at annual ryegrass
Perhaps you’re a ‘short black’ wheat-canola type, strong on inputs? Or a ‘long black’ type who likes to dilute their rotations a bit more? Or are you a ‘double shot’, throwing in a few break crops in a row for maximum effect? When it comes to managing annual ryegrass populations, Tony Swan and the research team from CSIRO Plant Industry and FarmLink, have shown that ‘double shots’ are the key. Growing two break crops in sequence (broadleaf crop, hay crop or long fallow) was more effective in reducing resistant ryegrass numbers to manageable levels than a single break crop or continuous wheat over a three-year rotation. And it can still be profitable.
Increase pre-em efficacy through a mix and rotate strategy
Part 1: Control summer weeds for yield and profit Every $1 spent on summer weed control can potentially return up to $8/ha through moisture and nitrogen conservation. The impact on grain yield as a result of various summer weed control treatments is what Colin McMaster (NSW DPI R&D) refers to as “buying a spring”. Listen to Colin and Pete Newman (AHRI) as they investigate the $$ benefits of controlling summer weeds. Resources: Ask an Expert column with Colin McMaster GRDC Summer Fallow Weed Management Manual Part 2: Increase pre-em efficacy through a mix and rotate strategy We’ve done a good job of promoting herbicide rotation over the years. And whilst this advice still stands, recent research shows the benefits of mixing herbicides as well. As American weeds researcher, Pat Tranel, puts it, “rotating buys you time, mixing buys you shots (of herbicide)”. Listen to Pat and Pete as they explore the benefits of the mix and rotate strategy.
Post emergent herbicides
Resources Spray resistant radish early for best efficacy and yield (Grant Thompson, Crop Updates paper 2014) Herbicide resistant wild radish (Peter Newman) Controlling herbicide resistant Wild Radish in wheat in the Northern Agricultural Region of WA with a two spray strategy (Peter Newman) Diverse weed control: Left jab, right hook (AHRI insight) Part 2:When is it worth rotating from clethodim (Select®) to butroxydim (Factor®)? Is there any value in rotating the post-emergent herbicides clethodim (Select®) and butroxydim (Factor®)? The research suggests that Factor® will sometimes kill plants that are moderately-resistant to Select® that could help in driving down the weed seed bank. Dr Peter Boutsalis from the University of Adelaide discusses his latest research and observations using both products with AHRI’s Peter Newman.