MCPB (Thistrol)
Rate 0.5 to 1.5 lb ae/A (2 to 6 pints/A). Use higher rate during cool weather.
Time Apply when peas have six to twelve nodes, but before flower buds form, and Canada thistle is 4 to 10 inches tall.
Remarks Canada thistle is only suppressed and usually re-grows.
Caution Do not permit MCPB to drift off target. Do not feed peas or vines to livestock. Do not apply if temperature is expected to exceed 85°F within the next 24 hours. Do not spray peas under moisture stress.
Site of action Group 4: synthetic auxin
Chemical family Phenoxy acetic acid