طریقه عملکرد علف کش ها

صفحه 1:
Herbicide Modes of Action Lectures 15, 16 

صفحه 2:
Herbicide Mode of Action Contact Types Chronic Types * Rapid * Relatively slow development of development of symptoms symptoms * Short distance 0 transport 

صفحه 3:
Herbicide Mode of Action Cell Growth Disruption * Mimic naturally occurring plant hormones & interferes with nucleic oot TW XS ‏ل ا‎ proliferation * Soil and foliar activity * Dicots are more sensitive ° Symptoms from foliar treatment apparent in 1-7 days 

صفحه 4:
نم م۱9 * Phenoxycarboxylic Acids * Benzoic acid ‏وان‎ 

صفحه 5:
Herbicide Mode of Action Cell Growth Disruption * Dicot symptoms * Monocot 0 ‏ال‎ yam 000 eyeekcy peel ee eeael - 021012-121110 OMS - brittle stalks ۲ 3 - fused brace roots - callous stem tissue - ‏عصوهواه ت#مبسنم‎ ۱ ‏تس یت‎ - malformed seed - ‏]د‎ 6171 55 22106 5 ‏ا‎ ey I LAaTeLeg 

صفحه 6:
۱0۱/۰ vP Oitosts 1001: Shoot Awe Ria Co ‏ا نان‎ Inhibitors Inhibitors ¢ Dinitroanilines ‏ال‎ ‎۳۹ * Benzenedicarboxylat © ‏ا‎ [cs - * Benzamide * Substituted Pyridine * Phosphorothioate * Nitrile 

صفحه 7:
Herbicide Mode of Action Root Meristematic Inhibitors eased * Monocot ٠ 0100: ‏يه‎ ‎symptoms - stunting ۳ = ‏ی‎ secondary - lack of secondary ‏و‎ ‎TOES, shy elee a zd ee haa ake - stem brittleness shoots 505777 - symptoms appear 00 ا ‎DS‏ 5ه 7-10 12 

صفحه 8:
مد سس ا ‎Curctowids‏ ۱ * Triazole ¢ Pyridazinone * Isoxazolidinone 

صفحه 9:
Herbicide Mode of Action Pigment Inhibitors * Inhibit production of plant pigments, disrupts carotene development * Root uptake * Symptoms appear as bleaching on 116117 5 * Symptoms appear within 10 days of 102001111 

صفحه 10:
Grape Pukwoy Thiers Protoporphyrinogen Oxidase (PPO) Inhibitors ¢ Diphenyl ethers ¢ N-Phenylphthalimide * Oxadiazole 

صفحه 11:
PPO (Protoporphyrinogen Oxidase) * Enzymatic 11100 found in chloroplasts and mitochondria and PN My evar OCB RTC 0 ‏ل‎ Ze breakdown of cell constituents 

صفحه 12:
‎Tahbitors‏ ا ‎۱۵۱۱/۵ EF (PS D ‎¢ Bipyridiniums 

صفحه 13:
Herbicide Mode of Action Photosynthetic Inhibitors PS I * MOA-produce superoxides which destroy plant cells * Cell destruction is rapid and apparent in a few hours * Contact herbicides * Symptoms: chlorosis, necrosis 

صفحه 14:
‎Tahbitors‏ ا ‎Photosystem II--site B ‎* Phenylureas ‎* Uracils ‎٠ 115 ‎* Benzothiadiazoles ‏اه‎ ‎* Phenyl-pyridazine * Phenylcarbamate ‏ا 0 ذا 51106 ‏انال ين ‎Triazinones‏ ¢ 

صفحه 15:
Herbicide Mode of Action Photosynthetic Inhibitors PS II * Bind with a pigment protein in thylakoid membrane of chloroplasts * Absorbed by roots & foliage, translocate ° Symptoms: Foliar uptake Sea K LIM KTR a hse Bhd - symptoms appear in a few days * Symptoms: Root uptake - interveinal chlorosis, beginning with older leaves - symptoms appear in 1 to 3 weeks 

صفحه 16:
Grape Pukwoy Thiers Acetyl CoA Carboxylase (ACCase) Inhibitors * Aryloxyphenoxypropionates * Cyclohexanediones 

صفحه 17:
Herbicide Mode of Action Enzyme Pathway Inhibitors ACCase (Acetyl CoA Carboxylase ) Inhibit synthesis of lipids in grasses * Site of action is the enzyme acetyl CoA carboxylase, located in stroma of ۱/۵ * Grasses do not have this enzyme, tolerant species do * Foliar treatment only 

صفحه 18:
Grape Pukwoy Thiers Acetolactate Synthase (ALS) ۱۱۱۱۱۱۱۱ ey Sulfonylureas Imidazolinones Sulfonamides Pyrimidinylthiobenzoate 

صفحه 19:
Herbicide Mode of Action Enzyme Pathway Inhibitors ALS (Acetolactate Synthase) 0 oye Oyime TKO) Lele nel RCM Zs1BITeR Ic} enzyme * Catalyzes the first step in biosynthesis of valine, leucine and isoleucine * Root and foliar uptake 

صفحه 20:
Grape Pukwoy Thiers EPSP Synthase Inhibitors * Glycines 

صفحه 21:
Herbicide Mode of Action Enzyme Pathway Inhibitors EPSP Synthase Inhibitors 5-enolpyruvylshikimate-3phosphate * Blocking this enzymatic step prevents formation of phenylalanine, tryptophane, ۱2۹ 

صفحه 22:
Grape Pukwoy Thiers Glutamine Synthetase Inhibitor ‏ار‎ 

صفحه 23:
Herbicide Mode of Action Enzyme Pathway Inhibitors Glutamine Synthetase Inhibitor ° Inhibits the enzyme glutamine 0 ‏ا‎ LT RC) and causes photosynthesis to stop and disruption of chloroplasts ل 0 

صفحه 24:
Grape Pukwoy Thiers Others ¢ Methanearsonates ¢ Benzofurans 

Herbicide Modes of Action Lectures 15, 16 Herbicide Mode of Action Contact Types Chronic Types • Rapid development of symptoms • Short distance transport • Relatively slow development of symptoms • Systemic Herbicide Mode of Action Cell Growth Disruption • Mimic naturally occurring plant hormones & interferes with nucleic acid synthesis, causes massive cell proliferation • Soil and foliar activity • Dicots are more sensitive • Symptoms from foliar treatment apparent in 1-7 days Cell Growth Disruption • Phenoxycarboxylic Acids • Benzoic acid • Pyridines Herbicide Mode of Action Cell Growth Disruption • Dicot symptoms – dark green color – strap shaped leaves – leaf cupping – callous stem tissue – twisted stems – stem brittleness – stem splitting • Monocot symptoms – – – – – onion-leafing brittle stalks fused brace roots curved stems malformed seed heads Disruption of Mitosis Root Meristematic Inhibitors Shoot Meristematic Inhibitors • Dinitroanilines • Amides • Benzenedicarboxylat e • Benzamide • Substituted Pyridine • Phosphorothioate • Nitrile – Treflan – Prowl – Pre-M Herbicide Mode of Action Root Meristematic Inhibitors Dinitroanilines • Monocot symptoms – stunting – lack of secondary roots – reddish colored shoots – symptoms appear in 7-10 days • Dicot symptoms – stunting – lack of secondary roots – swollen / cracked hypocotyls – stem brittleness – symptoms • root 7-10 days • stem 6-8 weeks Pigment Inhibitors Inhibition of Caretonoids • Triazole • Pyridazinone • Isoxazolidinone Herbicide Mode of Action Pigment Inhibitors • Inhibit production of plant pigments, disrupts carotene development • Root uptake • Symptoms appear as bleaching on new leaves • Symptoms appear within 10 days of treatment Enzyme Pathway Inhibitors Protoporphyrinogen Oxidase (PPO) Inhibitors • Diphenyl ethers • N-Phenylphthalimide • Oxadiazole PPO (Protoporphyrinogen Oxidase) • Enzymatic pathway is found in chloroplasts and mitochondria and blocks photosynthesis in the presence of light. Results in oxidative breakdown of cell constituents Photosynthetic Inhibitors Photosystem I (PS I) • Bipyridiniums Herbicide Mode of Action Photosynthetic Inhibitors PS I • MOA-produce superoxides which destroy plant cells • Cell destruction is rapid and apparent in a few hours • Contact herbicides • Symptoms: chlorosis, necrosis Photosynthetic Inhibitors Photosystem II-site A • Triazines • Triazinones Photosystem II--site B • Phenylureas • Uracils • Nitriles • Benzothiadiazoles • Amides • Phenyl-pyridazine • Phenylcarbamate Herbicide Mode of Action Photosynthetic Inhibitors PS II • Bind with a pigment protein in thylakoid membrane of chloroplasts • Absorbed by roots & foliage, translocate • Symptoms: Foliar uptake – interveinal chlorosis of treated leaves – symptoms appear in a few days • Symptoms: Root uptake – interveinal chlorosis, beginning with older leaves – symptoms appear in 1 to 3 weeks Enzyme Pathway Inhibitors Acetyl CoA Carboxylase (ACCase) Inhibitors • Aryloxyphenoxypropionates • Cyclohexanediones Herbicide Mode of Action Enzyme Pathway Inhibitors ACCase (Acetyl CoA Carboxylase ) Inhibit synthesis of lipids in grasses • Site of action is the enzyme acetyl CoA carboxylase, located in stroma of plastids • Grasses do not have this enzyme, tolerant species do • Foliar treatment only Enzyme Pathway Inhibitors Acetolactate Synthase (ALS) Inhibitors • Sulfonylureas • Imidazolinones • Sulfonamides • Pyrimidinylthiobenzoate Herbicide Mode of Action Enzyme Pathway Inhibitors ALS (Acetolactate Synthase) • Inhibition of acetolactate synthase enzyme • Catalyzes the first step in biosynthesis of valine, leucine and isoleucine • Root and foliar uptake Enzyme Pathway Inhibitors EPSP Synthase Inhibitors • Glycines Herbicide Mode of Action Enzyme Pathway Inhibitors EPSP Synthase Inhibitors 5-enolpyruvylshikimate-3phosphate • Blocking this enzymatic step prevents formation of phenylalanine, tryptophane, tyrosine Enzyme Pathway Inhibitors Glutamine Synthetase Inhibitor • Glycines Herbicide Mode of Action Enzyme Pathway Inhibitors Glutamine Synthetase Inhibitor • Inhibits the enzyme glutamine synthetase. ammonia accumulates and causes photosynthesis to stop and disruption of chloroplasts • Symptoms: chlorosis Enzyme Pathway Inhibitors Others • Methanearsonates • Benzofurans