Download Using Herbicides to Manage Noxious Weeds

Exploring Herbicides Used
to Control Invasive Weeds
Herbicide Classification
Herbicide Classification
Many Schemes
Degree of response among plants:
• selective
 controls some species in presence of others
• non-selective
 controls all species
Herbicide Classification
Method of application:
• foliar applied
• soil applied
• broadcast
 entire area
• spot
 restricted area
• band
Herbicide Classification
Based upon use:
• Pre-plant incorporated (PPI)
 Mechanically incorporated before sowing crop
o Prevent photodecomposition, volatility
o Place herbicide where can be absorbed by sensitive
seedling tissues
• Pre-emergence
 Applied to soil surface before weed seedling
germination and emergence
• Post-emergence
 Applied to foliage of emerged weeds
Herbicide Classification
Length of soil persistence:
• persistent
 injure follow crop normal rotation
• residual
 injure/kill germinating weeds short time
o 1 growing season or less
• long residual
 control several growing seasons
Herbicide Classification
Chemistry/herbicide family:
• inorganics
• organics
Herbicide Classification
Organics:
• phenoxy-, benzoic-, pyridine-, quinolinecarboxylic
acids
• sulfonylureas, imidazolinones, triazolopyrimidine
• triazines, substituted ureas, uracils
• thiocarbamates, halogenated acids
• dinitroanilines, carbamates, phosphoric amides
• aryloxyphenoxypropionates, cyclohexanediones
• nitrodiphenyl ethers
• those with no particular family
Herbicide Classification
Plant related characteristics:
• systemic
 translocates throughout plant
• contact
 no translocation
• mode/mechanism of action
Herbicide Classification
Mode/mechanism of action:
• amino acid biosynthesis inhibitors:
 Escort, Amber, Plateau, Roundup
• auxin-like/growth regulators
 Tordon, Milestone, 2,4-D, Vanquish/Clarity
• Light activated:
 photosynthetic inhibitors
o Velpar, Karmex, Krovar, Spike
 Pigment synthesis inhibitors
o Callisto (mesotrione)
 Cell membrane disruptors
Herbicide Classification
Mode/mechanism of action:
• cell division inhibitors
 Treflan, Prowl
• lipid biosynthesis inhibitors (cell
membranes)
 Poast, Fusilade