Herbicide Injury Symptoms on Corn and Soybeans Department of Botany and Plant Pathology Purdue University West Lafayette, IN 47907 Page 1

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http://www.btny.purdue.edu/Extension/Weeds/HerbInj2/InjuryMOA1.html

Classified by Mode of Action

This section displays herbicide injury symptoms based on the mode of action of the herbicide, e.g. 2,4-D is in the Growth Regulator family.

Classified by Herbicide Active Ingredient

Select the "Classified by Herbicide Active Ingredient" link to view the section on herbicide injury symptoms based on the common name (active ingredient) of the herbicide. Most herbicide products will list the common name under the active ingredient section of the label. A cross reference list of trade names and common names can also be found in Weed Control Guidelines for Indiana WS-16.

Mode of Action Index:

Amino Acid Synthesis Inhibitor

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	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Chlorimuron Injury: Short "Bottle-Brush" Lateral Roots (Imazaquin can also display similar symptoms under different conditions) Condition: Carryover of herbicide due mostly to high soil pH (>6.8)
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Chlorimuron Injury: Interveinal Chlorosis (Imazaquin can also display similar symptoms under different conditions) Condition: Carryover of herbicide due mostly to high soil pH (>6.8)
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Chlorimuron Injury: Stunting of Plant (Imazaquin can also display similar symptoms under different conditions) Condition: Carryover of herbicide due mostly to high soil pH (>6.8)
	SOYBEAN Mode: Amino Acid Synthesis Inhibitor Herbicide: Chlorimuron Injury: Red Leaf Veins (Imazethapyr and Thifensulfuron can also display similar symptoms) Condition: Postemergence application made on days with high temperatures and humidity; misapplication
	SOYBEAN Mode: Amino Acid Synthesis Inhibitor Herbicide: Chlorimuron Injury: Reduced Root System Condition: An extended period of wet conditions following a soil application of the herbicide and planting of the crop
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Imazaquin Injury: Short "Bottle-Brush" Lateral Roots (Chlorimuron can also display similar symptoms under different conditions) Condition: Carryover of herbicide to corn due mostly to lack of moisture for adequate herbicide breakdown; secondary - very low soil pH, soils high in clay and organic matter content
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Imazaquin Injury: Interveinal Chlorosis (Chlorimuron can also display similar symptoms under different conditions) Condition: Carryover of herbicide to corn due mostly to lack of moisture for adequate herbicide breakdown; secondary - very low soil pH, soils high in clay and organic matter content
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Imazaquin Injury: Stunting of Plant (Chlorimuron can also display similar symptoms under different conditions) Condition: Carryover of herbicide to corn due mostly to lack of moisture for adequate herbicide breakdown; secondary - very low soil pH, soils high in clay and organic matter content
	SOYBEAN Mode: Amino Acid Synthesis Inhibitor Herbicide: Imazethapyr, Thifensulfuron Injury: Red Leaf Veins (Chlorimuron can also display similar symptoms) Condition: Postemergence application made on days with high temperatures and humidity; misapplication
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Nicosulfuron, Primisulfuron Injury: Yellowing of whorl, chlorotic patches across leaf, stunting of shoot; malformed leaves Condition: Postemergence herbicide applied during high temps and humidity, during stressed conditions (drought, compaction, etc.) or following the application of an organo-phosphate soil insecticide
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Nicosulfuron, Primisulfuron Injury: Reduction in kernel rows from butt to tip of ear Condition: Late postemergence herbicide applications where most of the corn leaves and whorl intercept the herbicide
	CORN Mode: Amino Acid Synthesis Inhibitor Herbicide: Glyphosate Injury: Bleached-white appearance of whorl or patches across leaf Condition: Drift of herbicide; symptom expressed dependent on degree of drift

Index