Understanding and identifying herbicide damage to plants Flashcards

Question 1

Q

Describe the mode of action, selectivity, and symptoms of herbicide damage from a GROUP A herbicide

Answer

A

MODE OF ACTION:

→ Inhibition of lipid biosynthesis

SELECTIVITY:

→ Selective in broadleaf plants (selects for grasses)

→ Some Group A herbicides are also selective in wheat and barley

SYMPTOMS:

→ Appear 7-10 days after spray application

*** Center leaves easily pulled out

→ Yellowing of leaf base

→ Interveinal chlorosis

→ Leaves discolour yellow to reddish at the top of the leaf

→ Leaf sheath stops elongating

= New leaves push out of the sheath incorrectly

→ For more tolerant grasses, the leaf blade may be pinched and white where the junction of the leaf blade and the new leaf was at the time of spraying.

→ Plants will appear stunted

Question 2

Q