GLYPHOSATE (ROUNDUP)

Mode of action: amino acid synthesis inhibition

Specific mode: inhibits EPSP synthetase
(stops production of phenylalanine, tryptophan and tyrosine)

Chemical family: amino acid derivative

Uptake: foliar only

Movement: systemic throughout plant

Common application: pre-plant

Weed control: non-selective, "TVC" total vegetation control

Weed stage: emerged

Potato injury: Growing cells (meristems) are affected and plant growth stops due to lack of protein. Injury appears in less than a week after exposure and starts with new, young leaves. Symptoms start with leaf yellowing (chlorosis) and progresses to browning (necrosis) until plants wilt and die. The process takes 10 to 14 days from exposure. There is no recovery. Sub-lethal doses cause parallel veining on leaves and an over-production of vegetative buds (similar to symptoms caused by phenoxy compounds such as 2,4D).