lecture 15

Question 1

what do group 9 herbicides inhibit?

Answer 1

5-enolpyruvylshikimate-3-photsphate

essential in creation of aromatic amino acids (EPSPS)

Question 2

group 9 single chemical

Answer 2

glyphosate - most widely used herbicide on the planet

Question 3

glyphosate (group 9) selectivity

Answer 3

non selective

grasses more susceptible

Question 4

four salts of group 9 (glyphosate)

Answer 4

Isopropyl amine (roundup)

Dimenthyl amine (vintage plus MaxII)

Potassium (roundup transorb)

Trimethylsulfonium salt (sulfosate)

Question 5

what can deactivate glyphosate in the tank?

Answer 5

Hard water containing Ca or Mg or iron

Question 6

group 9 target site

Answer 6

Shikimate pathway

Question 7

group 9 MOA

Answer 7

inhibits aromatic amino acid synthesis in chloroplasts

Question 8

group 9 injury

Answer 8

very phloem mobile

yellowing in growth point

relatively slow acting

Question 9

group 9 injury that may be mistaken for group 2

Answer 9

purpling

Question 10

group 9 selectivity (crops)

Answer 10

created artificially in glyphosate resistant crops - bacterial glyphosate oxidase gene

Question 11

group 9 tolerance trait

Answer 11

thick cuticle (not resistant but hard to control)

Question 12

group 9 two resistant weed biotypes

Answer 12

1) altered target site

2) reduced translocation

Question 13

what do group 10’s inhibit?

Answer 13

glutamine synthesis

Question 14

group 10 herbicide

Answer 14

glufosinate ammonium

Question 15

group 10 main use

Answer 15

in liberty link canola

Question 16

are group 10’s selective?

Answer 16

non selective, contact herbicide

Question 17

group 10’s affect on perennial(weak or strong)

Answer 17

weak on perennial weeds

Question 18

group 10 MOA

Answer 18

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

Question 19

group 10 plant injury

Answer 19

contact herbicide

chlorosis in 3-5 days

necrosis in 1-2 weeks

Question 20

group 10 selectivity

Answer 20

almost non- selective

Question 21

group 10 risk of resistance (high or low)

Answer 21

relatively low

• used once per crop rotation