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