The right weed control decisions at sprayout, prior to sowing annual ryegrass, can help prevent the recurrence of persistent perennial broadleaf weeds.
The economic benefit of annually renewing a percentage of permanent pasture is well-accepted. The decision to renew a pasture is usually triggered when its production drops significantly, often as a result of heavy infestations of deep-rooted perennial broadleaf weeds which survive any attempt to control them with ’clover friendly’ herbicides.
A proven strategy for astute farmers is to build a cropping programme around pasture renewal. Annual ryegrass in the pasture renewal cycle creates a great opportunity for farmers to clean up dirty paddocks where deep-rooted perennial weeds have become impossible to control.
Using annual ryegrass as part of the pasture renewal programme creates a rare opportunity to achieve long-term control of hard-to-kill weeds such as Californian thistle, dock and, in more recent years, oxeye daisy which are not well-controlled by ‘clover safe’ pasture herbicides. However, until recently no herbicide has provided reliable control of these deep-rooted perennial weeds.
While glyphosate is very effective for grassweed control, broadleaf weeds are not so well controlled by glyphosate alone. Various broadleaf herbicides and adjuvants are often added to glyphosate to improve broadleaf weed control, but deep-rooted perennial broadleaf weeds such as docks, Californian thistle and oxeye daisy often re-grow because their root systems are not totally killed. Consequently, while control might look good two or three weeks after a spray application, a short time later these weeds re-emerge, having re-grown from live root remnants. If these weeds are not well-controlled in the cropping phase of the pasture renewal cycle, they quickly become an issue in subsequent permanent pasture.
However, there is now a reliable solution. Due to its ability to readily move through the sap stream and completely kill the root system, ‘aminopyralid’, a unique active ingredient in T-MAX™ has proven to be highly effective in controlling deep-rooted perennial broadleaf weeds. A new registration for T-MAX allows tank mixing with glyphosate at spray-out, prior to sowing annual ryegrass. T-MAX is proven to destroy the entire root system and prevent regrowth so is a very useful tool in the pasture renewal cycle.
If you’re sowing a straight annual ryegrass this autumn, T-MAX herbicide mixed with glyphosate at spray-out is the single most effective way to break the perennial broadleaf weed cycle and get high level control of these ‘hard-to-kill’ weeds prior to sowing. While ryegrass can be sown straight after T-MAX in a spray-out application, it is recommended to wait at least six months before re-establishing clover. Tank-mixing T-MAX with glyphosate prior to sowing annual grass in autumn provides a perfect buffer to ensure good clover establishment the following season. Effective control of deep-rooted perennial weeds at sprayout means no residual live root chips in the ground to regenerate when you return to permanent pasture the following season.
Using T-MAX at sprayout prior to sowing annual ryegrass effectively breaks the cycle of perennial broadleaf weeds, meaning cleaner, more persistent and more productive permanent pastures.
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For more information on using T-MAX at sprayout prior to sowing annual ryegrass, talk to your local Fonterra Farm Source TSR.
Article supplied by Dow AgroSciences