Ohio State University Extension/Research

Weed Control Guide for Ohio Field Crops

Roundup Ready Corn - Postemergence Herbicides

Herbicide Formulation Product Rate Range

Ready Master ATZ 4L 1.5 - 2 qt

Tank-mix with: Atrazine, Harness, Micro-Tech, Partner

Ready Master ATZ is a premix of atrazine plus glyphosate (Roundup Ultra Max) that controls emerged weeds and provides residual broadleaf weed control. Can be applied postemergence in Roundup Ready corn only.
Mode of action: photosynthesis inhibitor (atrazine), EPSP synthase inhibitor (glyphosate).
Apply when weeds are 2 to 4 inches tall. Use the higher rate for control of fall panicum and Pennsyvania smartweed, in dense weed populations, and where targeting perennial weeds.
Apply in a spray volume of 10 to 25 gpa before corn exceeds 12 inches in height.
The addition of ammonium sulfate (17 lbs/100 gallons) is recommended when tank-mixing with residual corn herbicides, when weeds are subject to stress from cool temperatures or other factors, and when hard or high pH water is used as the carrier.

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Herbicide	Formulation	Product Rate Range
Ready Master ATZ	4L	1.5 - 2 qt