lecture 15 Flashcards
what do group 9 herbicides inhibit?
5-enolpyruvylshikimate-3-photsphate
essential in creation of aromatic amino acids (EPSPS)
group 9 single chemical
glyphosate - most widely used herbicide on the planet
glyphosate (group 9) selectivity
non selective
grasses more susceptible
four salts of group 9 (glyphosate)
Isopropyl amine (roundup)
Dimenthyl amine (vintage plus MaxII)
Potassium (roundup transorb)
Trimethylsulfonium salt (sulfosate)
what can deactivate glyphosate in the tank?
Hard water containing Ca or Mg or iron
group 9 target site
Shikimate pathway
group 9 MOA
inhibits aromatic amino acid synthesis in chloroplasts
group 9 injury
very phloem mobile
yellowing in growth point
relatively slow acting
group 9 injury that may be mistaken for group 2
purpling
group 9 selectivity (crops)
created artificially in glyphosate resistant crops - bacterial glyphosate oxidase gene
group 9 tolerance trait
thick cuticle (not resistant but hard to control)
group 9 two resistant weed biotypes
1) altered target site
2) reduced translocation
what do group 10’s inhibit?
glutamine synthesis
group 10 herbicide
glufosinate ammonium
group 10 main use
in liberty link canola
are group 10’s selective?
non selective, contact herbicide
group 10’s affect on perennial(weak or strong)
weak on perennial weeds
group 10 MOA
binds irreversibly to active site of GS
GS= assimilates inorganic N to organic N
results in rapid accumulation of excess ammonia –> indirect inhibition of photosynthesis due to lack of glutamine
group 10 plant injury
contact herbicide
chlorosis in 3-5 days
necrosis in 1-2 weeks
group 10 selectivity
almost non- selective
group 10 risk of resistance (high or low)
relatively low
- used once per crop rotation
