Lecture 13 group 1 Flashcards
Herbicide Modes of Action
What do Group 1 herbicides inhibit?
Fatty acid / lipid biosynthesis
ACCase inhibitors
is there high soil residual for group 1’s?
no - rapidly degraded in soil (microbial)
what tissues do group 1’s damage?
meristem tissue
do group 1’s effect broadleaves?
no
three classes of group 1 ACCase inhibitors
1) Aryloxyphenoxy Propionates - “fops”
2) Cyclohexanediones - “dims”
3) Phenylpyrazolin - “dens”
Aryloxyphenoxy Propionates “fops” properties
pro - herbicides with methyl, ethyl and butyl groups
Typically parent is acid so needs alcohol group to move past into plant
Aryloxyphenoxy Propionates - Fops, Dims or Dens?
Fops
Cyclohexanediones “dims” properties
photodegredate, breakdown when exposed to light
Cyclohexanediones - Fops, Dims or Dens?
Dims
Phenylpyrazolin “dens”
newest class
Phenylpyrazolin - Fops, Dims or Dens?
Dens
Aryloxyphenoxy Propionates (AOPP) examples
Clodinafop - propargyl
Fenoxaprop-p-ethyl
Fluizafop-p-butyl
Quizalofop
Cyclohexanediones (CD) examples
Clethodim
Sethoxydim
Tepraloxydim
Tralkoxydim
Phenylpyrazolin example
Pinoxaden
group 1 MOA and injury
- inhibit enzyme Acetyl CoA Carboxylase (ACCase) -> essential for fatty acid biosynthesis for membrane production
- loss of cell integrity
- injury at growth point, yellowing, inhibit meristem, young leaves pull out
