7Herbicide Injury. Symptoms

Transcription

1 7Herbicide Injury Symptoms Most observed herbicide damage is due to misapplication, but hybrid and environment interactions will sometimes cause injury symptoms to appear. Herbicides used to control weeds in the previous crop must be taken into consideration, as some herbicide carryover may affect the following corn crop. Various tankmixes of herbicides are widely used. Be alert to plant injury that can be caused by individual tankmix components or by an interaction involving two or more components in the tankmix itself. Corn plants frequently outgrow the effects of herbicide injury and their final yields may not be noticeably lowered. ACCase s Aryloxyphenoxy Propionic Acids and Cyclohexanediones (Including Assure II, Fusion, Poast and Select Max ) Symptoms of damage from acetyl coa carboxylase inhibitors include chlorosis (yellowing) of newly formed leaves with possible reddening or purpling of older leaves. Tissues at the growing point turn brown and eventually decompose, a symptom called deadheart. Sublethal doses result in pale white to yellow streaks between leaf veins. ALS s Imidazolinones, Sulfonylureas, and s (Including Accent Gold, Beacon, Classic, FirstRate, Lightning, Pursuit, and Scepter ) These herbicides alter the function of the acetolactate synthase (ALS) enzyme and affect root and shoot growth and development. Corn injury typically shows up as reduced root systems, often described as bottle-brush roots. Roots often grow flat or parallel to the soil surface and may turn brown. Stems and midribs can purple, and the stem will be short and thick below the whorl. Mid to late-season symptoms include short internodes, malformed leaves, poor root systems, and pinched ears. Herbicides with sulfonylurea chemistry are labeled for use on both corn and soybeans. Products in this family may persist in the soil, particularly if soil ph is above 6.8 and post-application rainfall has been limited. Though they have the same general chemistry, different herbicides are used on corn and soybeans, and injury of corn may develop the season following sulfonylurea herbicide application to soybean fields. 40

2 Synthetic s Benzoic Acids, Phenoxys, and Pyridine Carboxylic Acids (Including Banvel, Butyrac, Clarity, and Crossbow ) These herbicides, also known as plant growth regulators, are translocated to meristematic tissue and interfere with cell formation resulting in abnormal root and shoot growth. Symptoms include twisted whorls or buggy-whipping where the leaves do not unfurl, abnormal brace roots, root proliferation, brittle stalks, and poor pollination. Growing conditions are a factor in damage expression. Transport s Semicarbazones (Including Distinct and Status ) These herbicides are primarily active against broadleaf plants, but injury symptoms may occur in corn under certain conditions. Injury is similar to growth regulator herbicides. Carotenoid Synthesis s Isoxazolidinones (Including Command ) Shallow planting or stress conditions that slow seedling metabolism can increase the potential for injury. Damage to corn seedlings the season following an application may occur, especially if soil ph is below 6.0. Affected plants are distinctly white or bleached. Most corn plants recover and new leaves have normal color. Cell Division s s (Including Degree, Dual II Magnum, and Harness ) s (also known as acetanilides, acetamides, or chloroacetamides) are meristematic growth inhibitors that are translocated to the shoot and leaves. These products can cause seedlings to leaf underground or trap seedling leaves so they cannot unfurl, giving a ladder effect. Damage is more likely to take place with cool, wet weather occurring immediately before emergence. EPSP Synthase s Glycines (Including Roundup agricultural herbicides and generic formulations of glyphosate) These non-selective foliar-applied herbicides are translocated and interfere with amino acid synthesis. If spray drift reaches corn, leaves wilt, turn brown, and die. Sublethal rates can cause phenoxy-like symptoms. Glyphosate applications that occur too late to corn with Roundup Ready 2 Technology can result in poor kernel set. Glutamine Synthase s Phosphinic Acids (Including Ignite and Liberty ) s of glutamine synthase are nonspecific and will kill plants that have not been modified to express 41 Corn Diagnostic Guide

3 resistance to them. Symptomology will range from light speckling on leaves and yellowing to plant death, depending on the degree and intensity of drift or spray contamination. 4-HPPD s Isoxazoles and Triketones (Including Balance, Balance Pro, Callisto, and Impact ) Injury symptoms range from minor yellowing, through completely bleached plants, to significant stand loss. Shallow planting or stress conditions that slow seedling metabolism can increase the potential for injury. New tissue development should not be affected and the effect of injury on yield potential will vary from field to field. Microtubule s s (Including Prowl and Treflan ) s function by inhibiting root and shoot growth. Injury can occur due to carryover from an application made the previous season. Seedling roots are pruned and clubbed. Stunting and purplish discoloration may occur above ground. Symptoms may be confused with nematode damage. PPO s s, Phenylphthalimides, Pyrimidines, and Triazolinones (Including Aim, Authority, FlexStar, Reflex, and Resource ) Herbicide application during hot, humid conditions or before a long period of cool weather can result in crop injury. Drift injury can occur if application takes place under windy conditions. Symptoms range from leaf speckling to browning and death of entire leaves. If enough plant tissue is affected, the plant may wilt and die. The season following application in soybeans, non-degraded herbicide residue can cause interveinal bleaching and discoloration of corn seedlings if post-application rainfall was unusually low. Photosystem I Electron Diversion Bipyridiliums (Including Gramoxone Inteon ) Drift of these non-selective contact herbicides may cause leaf spotting. Symptoms can be confused with disease; however, the dead leaf areas will not spread. Photosystem II s mobile within plant Triazines and Ureas (Including atrazine, AAtrex, Princep, Sencor and Lorox ) These chemical families inhibit photosynthesis, which leads to leaf yellowing, browning, and death, usually starting at the leaf margins and tip. New leaves may be symptom-free. Symptoms are more common on sandy soil where an excessive rate was applied. Unfavorable growing conditions may accentuate plant injury. Photosystem II s nonmobile within plant Benzothiadiazoles and Nitriles (Including Basagran and Buctril ) These are contact herbicides that are absorbed through the foliage. Leaf speckling after foliar application is a common injury symptom. 42

4 Herbicides that may be used or trigger symptomology in corn, grouped by mode of action and class of chemistry. HERBICIDE MODES OF ACTION CLASS OF CHEMISTRY TRADEMARK OWNER Acetyl CoA Carboxylase s Assure II Fusilade DX Fusion Hoelon ACCase ACCase ACCase + ACCase ACCase Acetyl CoA Carboxylase s Poast Poast Plus Select Select MAX ACCase ACCase ACCase ACCase Acetolactate Synthase s Authority Assist Optill Lightning Pursuit Pursuit Plus Raptor Scepter Squadron Steel ALS + PPO ALS + PPO ALS + ALS ALS ALS + Microtubule ALS ALS ALS + Microtubule ALS + ALS + Microtubule Acetolactate Synthase s Accent Accent Gold Authority XL Beacon Canopy Celebrity Plus Classic Exceed NorthStar Option Peak Permit Realm Q Resolve Q Spirit Steadfast Steadfast ATZ Synchrony XP Valor XLT Yukon ALS ALS + ALS + ALS + PPO ALS + ALS ALS + PPO ALS + + Transport ALS ALS + ALS ALS ALS + ALS ALS + 4-HPPD ALS + ALS ALS + ALS ALS + ALS ALS + ALS + PS II ALS + ALS PPO + ALS r ALS + Aryloxphenoxypropionates Aryloxyphenoxypropionate Aryloxyphenoxypropionate Aryloxyphenoxypropionate + Aryloxyphenoxypropionate Aryloxyphenoxypropionate Cyclohexanediones Cyclohexanedione Cyclohexanedione Cyclohexanedione Cyclohexanedione Imidazolinones Imidazolinone + Triazolinone Imidazolinone + Pyrimidinedione Imidazolinone + Imidazolinone Imidazolinone Imidazolinone + Imidazolinone Imidazolinone Imidazolinone + Imidazolinone + Imidazolinone + Sulfonylureas Sulfonylurea Sulfonylurea + Sulfonylurea + + Pyridine Sulfonylurea + Triazolinone Sulfonylurea Sulfonylurea + Triazine Sulfonylurea + Benzoic Acid + Semicarbazone Sulfonylurea Sulfonylurea + Sulfonylurea Sulfonylurea + Benzoic Acid Sulfonylurea Sulfonylurea Sulfonylurea Sulfonylurea + Triketone Sulfonylurea + Sulfonylurea Sulfonylurea + Sulfonylurea Sulfonylurea + Sulfonylurea Sulfonylurea + Sulfonylurea + Triazine Sulfonylurea + Sulfonylurea Phenylphthalimide + Sulfonylurea Benzoic Acid + Sulfonylurea Nissan Chemical Industries, Ltd Nissan Chemical Industries, Ltd. Herbicides shown in bold type contain two or more active ingredients, so they may appear in more than one section of the table. 43 Corn Diagnostic Guide

5 HERBICIDE MODES OF ACTION CLASS OF CHEMISTRY TRADEMARK OWNER Acetolactate Synthase s Accent Gold Authority First Broadstrike FirstRate Gangster Gauntlet Hornet Python SureStart TripleFLEX Herbicide Banvel Celebrity Plus Clarity Distinct Marksman NorthStar Status Yukon 2,4-D Butyrac Crossbow Accent Gold Crossbow Hornet Stinger SureStart Tordon Transline TripleFLEX Herbicide WideMatch Celebrity Plus Distinct Status ALS + ALS + ALS + ALS + PPO ALS ALS ALS + PPO ALS + PPO ALS + ALS ALS + + Cell Division Cell Division + + ALS Synthetic s ALS + + Transport + Transport + PS II ALS Transport ALS + Synthetic s + Synthetic s ALS + ALS + ALS + + ALS + ALS + + Cell Division Cell Division + + ALS + Transport s ALS + + Transport + Transport + + Transport s Pyridine + Sulfonylurea + Sulfonylurea + + Triazolinone + Phenylphthalimide + Triazolinone + Pyridine + Pyridine + + Pyridine + Benzoic Acids Benzoic Acid Sulfonylurea + Benzoic Acid + Semicarbazone Benzoic Acid Benzoic Acid + Semicarbazone Benzoic Acid + Triazine Sulfonylurea + Benzoic Acid Benzoic Acid + Semicarbazone Benzoic Acid + Sulfonylurea Phenoxy Carboxylic Acids Phenoxy Phenoxy Phenoxy + Pyridine Pyridine Carboxylic Acids Pyridine + Sulfonylurea + Sulfonylurea + Phenoxy + Pyridine + Pyridine Pyridine + Pyridine + Pyridine Pyridine + Pyridine + Pyridine + Pyridine Semicarbazones Sulfonylurea + Benzoic Acid + Semicarbazone Benzoic Acid + Semicarbazone Benzoic Acid + Semicarbazone Nissan Chemical Industries, Ltd. Generic chemical name Allbaugh, Inc.. Herbicides shown in bold type contain two or more active ingredients, so they may appear in more than one section of the table. 44

6 HERBICIDE MODES OF ACTION CLASS OF CHEMISTRY TRADEMARK OWNER Carotenoid Synthesis s Command Command Xtra Commence Axiom Define Degree Degree Xtra Domain Dual II Magnum Guardsman Max Expert Halex GT Harness Harness Xtra Lexar Lumax Micro-Tech Outlook Radius SureStart TripleFLEX Herbicide Verdict Warrant Herbicide Expert Flexstar GT Glyphomax Halex GT Roundup PowerMAX Roundup WeatherMAX Touchdown Ignite Liberty Liberty ATZ Carotenoid Synthesis Carotenoid Synthesis + PPO Carotenoid Synthesis + Micrutubule Cell Division s Cell Division + PS II Cell Division Cell Division Cell Division + PS II Cell Division + PS II Cell Division Cell Division + PS II Cell Division + PS II + EPSPS Cell Division + 4-HPPD + EPSPS Cell Division Cell Division + PS II Cell Division + 4-HPPD + PS II Cell Division + 4-HPPD + PS II Cell Division Cell Division Cell Division + 4-HPPD ALS + + Cell Division Cell Division + + ALS PPO + Cell Division Cell Division EPSP Synthase s Cell Division + PS II + EPSPS PPO + EPSPS EPSPS Cell Division + 4-HPPD + EPSPS EPSPS EPSPS EPSPS Glutamine Synthase s GS GS GS + PS II Isoxazolidinones Isoxazolidinone Isoxazolidinone + Triazolinone Isoxazolidinone + Triazolinone s + Glycine + Triketone + Glycine + Triketone + Triazine + Triketone + Triazine + Isoxazole + Pyridine + + Pyridine + Pyrimidinedione + Chloroacetamide Glycines Glycine + Triazine + Glycine Glycine + Isoxazole + Glycine Glycine Glycine Glycine Phosphinic Acids Phosphinic Acid Phosphinic Acid Phosphinic Acid + Triazine FMC Coporation FMC Coporation Herbicides shown in bold type contain two or more active ingredients, so they may appear in more than one section of the table. 45 Corn Diagnostic Guide

7 HERBICIDE MODES OF ACTION CLASS OF CHEMISTRY TRADEMARK OWNER 4-Hydroxyphenyl-Pyruvate-Dioxygenase Balance Balance Flex Balance Pro Corvus Laudis Radius 4-HPPD 4-HPPD 4-HPPD 4-HPPD 4-HPPD Cell Division + 4-HPPD 4-Hydroxyphenyl-Pyruvate-Dioxygenase Callisto Halex GT Impact Lexar Lumax Realm Q Commence Pendimax Prowl Prowl H2O Pursuit Plus Sonalan Squadron Steel Treflan trifluralin 4-HPPD Cell Division + 4-HPPD + EPSPS 4-HPPD Cell Division + 4-HPPD + PS II Cell Division + 4-HPPD + PS II ALS + 4-HPPD Microtubule s Carotenoid Synthesis + Micrutubule Micrutubule Micrutubule Micrutubule ALS + Micrutubule Micrutubule ALS + Micrutubule ALS + ALS + Micrutubule Micrutubule Micrutubule Protoporphyrinogen Oxidase s Blazer Cobra FlexStar Flexstar GT Goal Phoenix Reflex Storm Ultra Blazer PPO PPO PPO PPO + EPSPS PPO PPO PPO PPO + PS II PPO Protoporphyrinogen Oxidase s Gangster Resource Valor SX Valor XLT ALS + PPO PPO PPO ALS + PPO Isoxazole Isoxazole Isoxazole Isoxazole Isoxazole Isoxazole + Isoxazole Triketones Triketone + Triketone + Glycine Triketone Triketone + Triketone + Triazine Sulfonylurea + Triketone s Isoxazolidinone + Imidazolinone + Imidazolinone + Imidazolinone + Imidazolinone + s + Glycine + Benzothiadiazole Phenylphthalimides + Phenylphthalimide Phenylphthalimide Phenylphthalimide Phenylphthalimide + Sulfonylurea Sygenta Sygenta. Amvac Chemical Corporation Sygenta Generic chemical name United Phosphorus, Inc. United Phosphorus, Inc. United Phosphorus, Inc. Herbicides shown in bold type contain two or more active ingredients, so they may appear in more than one section of the table. 46

8 HERBICIDE MODES OF ACTION CLASS OF CHEMISTRY TRADEMARK OWNER Protoporphyrinogen Oxidase s Optill Sharpen Verdict ALS + PPO PPO PPO + Cell Division Protoporphyrinogen Oxidase s Aim Authority Authority Assist Authority First Authority XL Command Xtra Gauntlet diquat Reward Gramoxone Inteon Basagran Laddok Storm Bison Buctril Moxy PPO PPO ALS + PPO ALS + PPO ALS + PPO Carotenoid Synthesis + PPO ALS + PPO r PPO Photosystem I Electron Diversion Aatrex atrazine Axiom Canopy Degree Xtra Domain Guardsman Max Harness Xtra Laddok Lexar Liberty ATZ Lumax Marksman Princep Sencor Steadfast ATZ PS I PS I PS I Photosystem II s PS II PS II + PS II PPO + PS II Photosystem II s PS II PS II PS II Photosystem II s PS II PS II Cell Division + PS II ALS + PS II Cell Division + PS II Cell Division + PS II Cell Division + PS II Cell Division + PS II PS II + PS II Cell Division + 4-HPPD + PS II GS + PS II Cell Division + 4-HPPD + PS II + PS II PS II PS II ALS + ALS + PS II Photosystem II s Pyrimidinediones Imidazolinone + Pyrimidinedione Pyrimidinedione Pyrimidinedione + Chloroacetamide Triazolinones Triazolinone Triazolinone Imidazolinone + Triazolinone + Triazolinone Sulfonylurea + Triazolinone Isoxazolidinone + Triazolinone + Triazolinone Triazolinone Bipyridilium Bipyridilium Bipyridilium Bipyridiliums Benzothiadiazoles Benzothiadiazole Benzothiadiazole + Triazine + Benzothiadiazole Nitrile Nitrile Nitrile Nitriles Triazines Triazine Triazine + Triazinone Sulfonylurea + Triazine Benzothiadiazole + Triazine + Isoxazole + Triazine Phosphonic Acid + Triazine + Isoxazole + Triazine Benzoic Acid + Triazine Triazine Triazine Sulfonylurea + Sulfonylurea + Triazine Ureas Generic chemical name United Phosphorus, Inc. Winfield Solutions, LLC Winfield Solutions, LLC Generic chemical name E.I. du Pont de Nemours & Co Lorox PS II Urea Herbicides shown in bold type contain two or more active ingredients, so they may appear in more than one section of the table. 47 Corn Diagnostic Guide

9 Herbicides by Active Ingredient and Mode of Action HERBICIDE ACTIVE INGREDIENT MODE OF ACTION 2,4-D 2,4-D AAtrex Atrazine PS II Accent Nicosulfuron ALS Accent Gold Clopyralid + Flumetsulam + Nicosulfuron + Rimsulfuron Aim Carfentrazone PPO Assure II Quizalofop ACCase atrazine Atrazone PS II Authority Sulfentrazone PPO ALS + ALS + ALS + Authority Assist Imazethapyr + Sulfentrazone ALS + PPO Authority First Cloransulam + Sulfentrazone ALS + PPO Authority XL Chlorimuron + Sulfentrazone ALS + PPO Axiom Flufenacet + Metribuzin Cell Division + PS II Balance Isoxaflutole 4-HPPD Balance Flexx Isoxaflutole 4-HPPD Balance Pro Isoxaflutole 4-HPPD Banvel Dicamba Basagran Bentazon PS II Beacon Primisulfuron ALS Bison Bromoxynil PS II Blazer Aciflourfen PPO Broadstrike Flumetsulam ALS Buctril Bromoxynil PS II Butyrac 2,4-DB Callisto Mesotrione 4-HPPD Canopy Chlorimuron + Metribuzin ALS + PS II Celebrity Plus Dicamba + Diflufenzopyr + Nicosulfuron ALS + + Transport Clarity Dicamba Classic Chlorimuron ALS Cobra Lactofen PPO Command Clomazone Carotenoid Synthesis Command Xtra Clomazone + Sulfentrazone Carotenoid Synthesis + PPO Commence Clomazone + Trifluralin Corvus Isoxaflutole 4-HPPD Crossbow 2,4-D + Triclopyr + Carotenoid Synthesis + Microtubule 48

10 Herbicides by Active Ingredient and Mode of Action (cont.) HERBICIDE ACTIVE INGREDIENT MODE OF ACTION Define Flufenacet Cell Division Degree Acetochlor Cell Division Degree Xtra Acetochlor + Atrazine Cell Division + PS II diquat Diquat PS I Distinct Dicamba + Diflufenzopyr + Transport Domain Flufenacet + Metribuzin Cell Division + PS II Dual II Magnum Metolachlor Cell Division Exceed Primisulfuron + Prosulfuron ALS + ALS Expert Atrazine + Glyphosate + Metolachlor FirstRate Cloransulam ALS Flexstar Fomesafen PPO Fusilade DX Fluazifop ACCase Cell Division + PS II + EPSPS Flexstar GT Fomesafen + Glyphosate PPO + EPSPS Fusion Fenoxaprop + Fluazifop ACCase + ACCase Gangster Cloransulam + Flumioxazin ALS + PPO Gauntlet Cloransulam + Sulfentrazone ALS + PPO Glyphomax Glyphosate EPSPS Goal Oxyfluorfen PPO Gramoxone Inteon Paraquat PS I Guardsman Max Atrazine + Dimethenamid Cell Division + PS II Halex GT Glyphosate + Mesotrione + Metolachlor Harness Acetochlor Cell Division Cell Division + 4-HPPD + EPSPS Harness Xtra Acetochlor + Atrazine Cell Division + PS II Hoelon Diclofop ACCase Hornet Clopyralid + Flumetsulam ALS + Ignite Glufosinate GS Impact Topramezone 4-HPPD Laddok Atrazine + Bentazon PS II + PS II Laudis Tembotrione 4-HPPD Lexar Atrazine + Mesotrione + Metolachlor Liberty Glufosinate GS Cell Division + 4-HPPD + PS II Liberty ATZ Atrazine + Glufosinate GS + PS II Lightning Imazapyr + Imazethapyr ALS + ALS Lorox Linuron PS II 49 Corn Diagnostic Guide

11 Herbicides by Active Ingredient and Mode of Action (cont.) HERBICIDE ACTIVE INGREDIENT MODE OF ACTION Lumax Atrazine + Mesotrione + Metolachlor Marksman Atrazine + Dicamba + PS II Micro-Tech Alochlor Cell Division Moxy Bromoxynil PS II NorthStar Dicamba + Primisulfuron ALS + Cell Division + 4-HPPD + PS II Optill Imazethapyr + Saflufenacil ALS + PPO Option Foramsulfuron ALS Outlook Dimethenamid Cell Division Peak Prosulfuron ALS Pendimax Pendimethalin Microtubule Permit Halosulfuron ALS Phoenix Lactofen PPO Poast Plus Sethoxydim ACCase Poast Sethoxydim ACCase Princep Simazine PS II Prowl Pendimethalin Microtubule Prowl H2O Pendimethalin Microtubule Pursuit Imazethapyr ALS Pursuit Plus Imazethapyr + Pendimethalin ALS + Mictrotubule Python Flumetsulam ALS Radius Flufenacet + Isoxaflutole Cell Division + 4-HPPD Raptor Imazamox ALS Realm Q Rimsulfuron + Mesotrione ALS + 4-HPPD Reflex Fomesafen PPO Resolve Q Rimsulfuron + Thifensulfuron ALS + ALS Resource Flumiclorac PPO Reward Diquat PS I Roundup PowerMAX Glyphosate EPSPS Roundup WeatherMAX Glyphosate EPSPS Scepter Imazaquin ALS Select Clethodim ACCase Select MAX Clethodim ACCase Sencor Metribuzin PS II Sharpen Saflufenacil PPO 50

12 Herbicides by Active Ingredient and Mode of Action (cont.) HERBICIDE ACTIVE INGREDIENT MODE OF ACTION Sonalan Ethalfluralin Microtubule Spirit Primisulfuron + Prosulfuron ALS + ALS Squadron Imazaquin + Pendimethalin ALS + Microtubule Status Dicamba + Diflufenzopyr + Transport Steadfast Nicosulfuron + Rimsulfuron ALS + ALS Steadfast ATZ Atrazine + Nicosulfuron + Rimsulfuron ALS + ALS + PS II Steel Imazaquin + Imazethapyr + Pendimethalin ALS + ALS + Microtubule Stinger Clopyralid Storm Bentazon PPO + PS II SureStart Acetochlor + Clopyralid + Flumetsulam ALS + + Cell Division SureStart Acetochlor + Clopyralid + Flumetsulam ALS + + Cell Division Synchrony XP Chlorimuron + Thifensulfuron ALS + ALS Tordon Picloram Touchdown Glyphosate EPSPS Transline Clopyralid Treflan Trifluralin Microtubule trifluralin Trifluralin Microtubule TripleFLEX Herbicide Acetochlor + Clopyralid + Flumetsulam Cell Division + + ALS Ultra Blazer Acifluorfen PPO Valor SX Flumioxazin PPO Valor XLT Flumioxazin + Chlorimuron PPO + ALS Verdict Dimethenamid + Saflufenacil PPO + Cell Division Warrant Herbicide Acetochlor Cell Division WideMatch Clorpyralid + Fluroxypyr + Yukon Dicamba + Halosulfuron ALS + 51 Corn Diagnostic Guide