Herbicide Injury Symptoms on Corn and Soybeans Department of Botany and Plant Pathology Purdue University West Lafayette, IN 47907 Page 2

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This web page address is:
http://www.btny.purdue.edu/Extension/Weeds/HerbInj2/InjuryMOA2.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:

Growth Regulator

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	CORN Mode: Growth Regulator Herbicide: 2,4-D or Dicamba Injury: Fused Brace Root Condition: Late application of herbicide where most of corn leaves and whorl intercept the herbicide; misapplication
	CORN Mode: Growth Regulator Herbicide: 2,4-D or Dicamba Injury: Rolled "buggy-whip" Whorl Condition: Late application of herbicide where most of corn leaves and whorl intercept the herbicide; misapplication
	SOYBEAN Mode: Growth Regulator Herbicide: 2,4-D Injury: Leaf Strapping Condition: 2,4-D drift from nearby field, roadside or other area where herbicide was applied; spray tank contamination
	SOYBEAN Mode: Growth Regulator Herbicide: Dicamba Injury: Leaf Cupping Condition: Dicamba drift from nearby field, roadside or other area where herbicide was applied; spray tank contamination

Growing Point Disintegrator

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	CORN Mode: Growing Point Disintegrator Herbicide: Fenoxaprop, Fluazifop, Quizalofop, Sethoxydim, Clethodim Injury: Bleached-white to translucent appearance of whorl or patches across leaf Condition: Drift of herbicide
	CORN Mode: Growing Point Disintegrator Herbicide: Fenoxaprop, Fluazifop, Quizalofop, Sethoxydim, Clethodim Injury: Rotten growing point, death of plant Condition: High degree of herbicide drift, misapplication

Seedling Growth Inhibitor

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	CORN Mode: Seedling Growth Inhibitor Herbicide: Ethalfluralin, Pendimethalin, Trifluralin Injury: Clubbed or Swollen Root Tips Condition: Carryover of herbicide due mostly to lack of moisture for breakdown or misapplication; stressed conditions (compaction)
	CORN Mode: Seedling Growth Inhibitor Herbicide: Ethalfluralin, Pendimethalin, Trifluralin Injury: Discolored shoot as a result of root injury Condition: Carryover of herbicide due mostly to lack of moisture for breakdown or misapplication; stressed conditions (compaction)
	SOYBEAN Mode: Seedling Growth Inhibitor Herbicide: Ethalfluralin, Pendimethalin, Trifluralin Injury: Clubbed or swollen root tips; swollen hypocotyl Condition: Overapplication of herbicide; stressed conditions (compaction)
	CORN Mode: Seedling Growth Inhibitor Herbicide: Alachlor, Metolachlor, Acetochlor, Dimethenamid Injury: Corn Leafing-out underground, improper leaf unfurling Condition: Misapplication - herbicide rate too high for soil type; stressed conditions (cool, wet soils) where corn is slowly growing
	SOYBEAN Mode: Seedling Growth Inhibitor Herbicide: Alachlor, Metolachlor, Acetochlor, Dimethenamid Injury: Leaf Malformation Condition: Overapplication of herbicide
	CORN Mode: Seedling Growth Inhibitor Herbicide: EPTC, Butylate Injury: Improper leaf unfurling, twisted whorls Condition: Misapplication; heavy rains soon after herbicide application that may leach away the herbicide safener; stressed conditions (cool, wet soils), certain hybrids may be sensitive

Index