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Accent / nicosulfuron

Chemical Structure

Chemical Name:


Chemical Family:

Sulfonyl ureas.

WSSA Resistance Group:


Crop/non-crop registration:

Field corn (not for use on some sweet or seed corn hybrids, check product label)

Sensitive weeds:

Annual grass species: green and yellow foxtail, fall panicum, barnyardgrass, witchgrass, proso millet; quackgrass, johnsongrass.

Application method:

POST- within 1-8 leaf stage of corn.

Absorption & Translocation:

Following foliar absorption, nicosulfuron is rapidly absorbed through the leaves and translocated via both xylem and phloem.

Mode of Action:

Inhibition of acetolactate synthase.

Metabolic pathway inhibited:

Inhibits acetolactate synthase (ALS), also called acetohydroxyacid synthase (AHAS), a key enzyme in the biosynthesis of the branched-chain amino acids isoleucine, lecucine, and valine.

Basis of Selectivity:

Metabolized by tolerant species to non-phytotoxic compounds.


Growth of treated plants is inhibited within a few hours after application;but injury symptoms appear more than 1-2 wks later. Meristematic areas gradually become chlorotic and necrotic, followed by a general foliar chlorosis and necrosis.


None; short (<1month).


Oral LD50 = >5000 mg/kg - practically non-toxic (ACCENT = >5000 mg/kg- practically non-toxic).

Additional comments:

Emerged grasses will be controlled but subsequent germinating grasses will not; a non-ionic surfactant must be added; do not apply to corn that has been treated with an organophosphorous soil insecticide (e.g. COUNTER).