طریقه عملکرد علف کش ها

طریقه عملکرد علف کش ها

اسلاید 1: Herbicide Modes of ActionLectures 15, 16

اسلاید 2: Herbicide Mode of ActionContact TypesRapid development of symptomsShort distance transportChronic TypesRelatively slow development of symptomsSystemic

اسلاید 3: Herbicide Mode of Action Cell Growth DisruptionMimic naturally occurring plant hormones & interferes with nucleic acid synthesis, causes massive cell proliferationSoil and foliar activityDicots are more sensitive Symptoms from foliar treatment apparent in 1-7 days

اسلاید 4: Cell Growth DisruptionPhenoxycarboxylic AcidsBenzoic acidPyridines

اسلاید 5: Herbicide Mode of Action Cell Growth DisruptionDicot symptomsdark green colorstrap shaped leavesleaf cuppingcallous stem tissuetwisted stemsstem brittlenessstem splittingMonocot symptomsonion-leafingbrittle stalksfused brace rootscurved stemsmalformed seed heads

اسلاید 6: Disruption of MitosisRoot Meristematic InhibitorsDinitroanilinesTreflanProwlPre-MShoot Meristematic InhibitorsAmidesBenzenedicarboxylateBenzamideSubstituted PyridinePhosphorothioateNitrile

اسلاید 7: Herbicide Mode of Action Root Meristematic InhibitorsMonocot symptomsstuntinglack of secondary rootsreddish colored shootssymptoms appear in 7-10 daysDicot symptomsstuntinglack of secondary rootsswollen / cracked hypocotylsstem brittlenesssymptomsroot 7-10 daysstem 6-8 weeks Dinitroanilines

اسلاید 8: Pigment Inhibitors Inhibition of Caretonoids TriazolePyridazinoneIsoxazolidinone

اسلاید 9: Herbicide Mode of Action Pigment InhibitorsInhibit production of plant pigments, disrupts carotene developmentRoot uptakeSymptoms appear as bleaching on new leavesSymptoms appear within 10 days of treatment

اسلاید 10: Enzyme Pathway InhibitorsProtoporphyrinogen Oxidase (PPO) InhibitorsDiphenyl ethersN-PhenylphthalimideOxadiazole

اسلاید 11: 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

اسلاید 12: Photosynthetic InhibitorsPhotosystem I (PS I)Bipyridiniums

اسلاید 13: Herbicide Mode of Action Photosynthetic Inhibitors PS IMOA-produce superoxides which destroy plant cellsCell destruction is rapid and apparent in a few hoursContact herbicidesSymptoms: chlorosis, necrosis

اسلاید 14: Photosynthetic InhibitorsPhotosystem II--site ATriazinesTriazinonesPhotosystem II--site BPhenylureasUracilsNitrilesBenzothiadiazolesAmidesPhenyl-pyridazinePhenylcarbamate

اسلاید 15: Herbicide Mode of Action Photosynthetic Inhibitors PS IIBind with a pigment protein in thylakoid membrane of chloroplastsAbsorbed by roots & foliage, translocateSymptoms: Foliar uptakeinterveinal chlorosis of treated leavessymptoms appear in a few daysSymptoms: Root uptakeinterveinal chlorosis, beginning with older leavessymptoms appear in 1 to 3 weeks

اسلاید 16: Enzyme Pathway InhibitorsAcetyl CoA Carboxylase (ACCase) InhibitorsAryloxyphenoxypropionatesCyclohexanediones

اسلاید 17: Herbicide Mode of Action Enzyme Pathway Inhibitors ACCase (Acetyl CoA Carboxylase )Inhibit synthesis of lipids in grassesSite of action is the enzyme acetyl CoA carboxylase, located in stroma of plastidsGrasses do not have this enzyme, tolerant species doFoliar treatment only

اسلاید 18: Enzyme Pathway InhibitorsAcetolactate Synthase (ALS) InhibitorsSulfonylureasImidazolinonesSulfonamidesPyrimidinylthiobenzoate

اسلاید 19: Herbicide Mode of Action Enzyme Pathway InhibitorsALS (Acetolactate Synthase)Inhibition of acetolactate synthase enzymeCatalyzes the first step in biosynthesis of valine, leucine and isoleucineRoot and foliar uptake

اسلاید 20: Enzyme Pathway InhibitorsEPSP Synthase InhibitorsGlycines

اسلاید 21: Herbicide Mode of Action Enzyme Pathway InhibitorsEPSP Synthase Inhibitors5-enolpyruvylshikimate-3phosphateBlocking this enzymatic step prevents formation of phenylalanine, tryptophane, tyrosine

اسلاید 22: Enzyme Pathway InhibitorsGlutamine Synthetase InhibitorGlycines

اسلاید 23: Herbicide Mode of Action Enzyme Pathway InhibitorsGlutamine Synthetase InhibitorInhibits the enzyme glutamine synthetase. ammonia accumulates and causes photosynthesis to stop and disruption of chloroplastsSymptoms: chlorosis

اسلاید 24: Enzyme Pathway InhibitorsOthersMethanearsonatesBenzofura