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8 Cards in this Set

  • Front
  • Back
What are the 5 growth regulators?
- auxins
- cytokinans
- abscissic acid (ABA)
- gibberellins
- ethylene
Phenoxys has 3 formulations. What are they and what makes either different?
salt formulation- not as quickly absorbed by plant foliage as ester; nonvolatile
ester formulation- low or high volatility; quickly absorbed by plant foliage and rain-fast; used during cool months
oil soluble amine salts- quickly absorbed and rain fast; nonvolatile; used during warm months
What is the mechanism of phenoxys?
- readily absorbed by foliage and roots; undergoes extensive translocation
- acidifies cell wall by stimulating ATPase proton pump which activates enzymes responsible for cell wall "loosening"
- results in cells undergoing rapid uncontrolled cell division and elongation
What other herbicides have the same mechanism as phenoxys?
Picolinic acids
Benzoic acids
What are other growth regulators and their mechanisms?
Naptalam- auxin-antagonist
Quinclorac- alters auxin transport
Diflufenzopyr- inhibits polar transport of auxin and synthetic auxins
Fenarimol- fungicide, reduces the biosynthesis of gibberellins
What are surfactants and what do they do?
Compounds added to POST herbicide application to improve performance.
- they contain the properties of both hydrophilic and lipophilic molecules
- used to reduce surface tension, spray tank compatibility, solubility, increase adhesion, buffer
What is the hydrophilic/lipophilic balance and what does it do?
HLB = 20 M(h)/M(h) + M(L)
- affects diffusion/interaction of surfactant with cuticle
High HLB (>11)- enhances diffusion of hydrophillic herbicides, through increasing the water holding capacity of the cuticle
Low HLB (<8)- enhances diffusion of lipophillic herbicides, through increasing the fluidity of the waxes in the cuticle
What is the difference between surfactants, crop oil, and organo-silicones?
Surfactants- non-ionic with 80% AI; reduce surface tension of spray droplet; reduces tension from plant hairs allowing herbicide to contact the cuticle directly
Crop oil- nonphytotoxic petroleum based oils that reduces surface tension and cuticle solubility
Organo-silicones- tremendous reduction in surface tension, allows solution to flow through stomatal cavity into plant