Lecture 2 Flashcards
What is a herbicide
kill unwanted plants
- can be used to kill specific weeds in crop/plantation
- non selectively to clear waste ground, industrial sites, etc..
How much use do the US account for
70% of all agricultural chemical use
What do herbicides affect
growth regulation
cell division
photosynthesis
amino acid biosynthesis
what are the hormones that control growth and development
auxin gibberellin abscisic acid cytokinins ethylene brassinosteroids
What was the first widely used herbicide
IAA
What are the syntehtic analogues of IAA
2,4-D
a-NAA
true or false; the synthetic analogues of IAA are more stable
true
what do auxins have in common
carboxyl group
ring structure
What is auxin involved in
cell division cell expansion differentiation ..... embryo genesis root initiation axillary bud growth tropisms fruit development
What does 2,4-D response depend on
tissue, dose, species
what is dinitroaniline
prevent microtubules forming
what is any example of a dinitroaniline
oryzalin
what does oryzalin bind to
a tubulin
What does oryzalin cause
root enlargement
root stubbiness
due to swollen cells that cannot complete mitosis
What is atrzine
interferes with the electron transport chain
inhibits PQ
- affects foliage system but root system is not
