In 2020, Corteva Agriscience introduced DuraCor® herbicide, with the first new active ingredient (Rinskor® active) available for rangeland and pasture use in nearly 15 years. Building on this innovation, the company has now introduced HighNoon™ herbicide, which also includes Rinskor and offers some additional flexibility in non-crop areas in select states. While HighNoon shares much in common with DuraCor and Milestone® herbicide, there are some distinct differences that make HighNoon a useful addition to the herbicide toolbox for meeting specific land management weed control challenges.
New HighNoon™ herbicide contains Rinskor® active (florpyrauxifen-benzyl) combined with the active ingredient in Milestone® herbicide, aminopyralid. Rinskor is unique and has been classified as Group O and is part of the arylpicolinates family. Arylpicolinates are differentiated for several factors, including use rate, spectrum, weed symptoms, environmental fate and molecular interaction. Rinskor is considered less volatile than auxins like 2,4-D ester and dicamba and it has high sorptivity to soil, which allows it to be classified as immobile. This profile earned Rinskor a Green Chemistry Challenge Award from the American Chemical Society’s Green Chemistry Institute, which recognizes new processes or products that help protect public health and the environment.
Because of their unique chemical profiles, both HighNoon™ and DuraCor® herbicides provide selective activity that helps maintain desirable vegetation in rangeland, pasture and non-crop areas. Selective activity allows these herbicides to control troublesome weeds without wiping out desirable vegetation and creating “moonscapes” in these open areas. Selective activity helps create healthier landscapes and can even enhance natural competition against weeds and invasives.
HighNoon, DuraCor and Milestone are all considered safe on grasses, and research indicates HighNoon and DuraCor are also similarly safe on desirable forbs, as seen in the chart below.1
HighNoon™ and DuraCor® herbicides each control about 50% more weeds than Milestone® herbicide. HighNoon and DuraCor also demonstrate better activity than Milestone on difficult weeds like late-season curly dock, knapweed, annual and bi-annual thistles (including Canada thistle), buckhorn plantain, mullein and the carrot family (including poison hemlock). HighNoon and DuraCor both provide good control on mustard species and Russian thistle when used as a preemergent.
So, with all these similarities among DuraCor®, Milestone® and HighNoon™ herbicides, when does it make sense to use HighNoon?
In non-crop areas in select states, HighNoon can be used up to 40 fl. oz. per acre – that’s 2X the use rate for DuraCor. In areas like rights-of-way, ditches, industrial sites and other locations that are not grazed or hayed, a higher application rate reduces labor and the need for re-treating. HighNoon offers all the same long-lasting, residual control seen in studies with DuraCor. In approved states, HighNoon can also be applied at 20 fl. oz./acre in rangeland and pasture areas just like DuraCor.* And because of the selective activity of HighNoon, land managers can rest assured that their weed control approach won’t also wipe out the landscape and leave the environment more hospitable to weeds and invasives down the line.
For land managers who already appreciate the weed control and environmental profiles of DuraCor® and Milestone® herbicides and need to manage non-crop areas as well, it may be high time for HighNoon™ herbicide. In western geographies in particular, HighNoon provides additional flexibility for treating non-crop areas. At the higher use rate for HighNoon in non-crop areas (40 fl. oz./acre), land managers can gain more complete control over troublesome weeds. At the 20 fl. oz./acre use rate, HighNoon is also a good option for land that is grazed and hayed, offering the same benefits and weed control profile as DuraCor herbicide, allowing land managers to use one new, reliable and effective product to help maintain the range of landscapes they care for.
1 Corteva Agriscience. Field observations. Data on file.
Under normal field conditions, DuraCor® and HighNoon® are non-volatile. DuraCor, HighNoon and Milestone® have no grazing or haying restrictions for any class of livestock, including lactating dairy cows, horses (including lactating mares) and meat animals prior to slaughter. Label precautions do apply to forage treated with DuraCor, HighNoon and Milestone and to manure and urine from animals that have consumed treated forage.
When treating areas in and around roadside or utility rights-of-way that are or will be grazed, hayed or planted to forage, important label precautions apply regarding harvesting hay from treated sites, using manure from animals grazing on treated areas or rotating the treated area to sensitive crops. Label precautions apply to forage treated with Milestone and to manure from animals that have consumed treated forage within the last three days.
DuraCor, HighNoon and Milestone are not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions.
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