picloram (Tordon)
Rate 0.25 to 0.5 lb ae/A
Time Apply in May to July. Timing is not critical.
Caution Most formulations are restricted-use herbicides. See label for grazing restrictions. Do not contaminate water. Potatoes, beans, and many other crops are very sensitive to picloram. Do not use in diversified cropping areas. Apply rates over 0.5 lb ae/A (1 quart/A) only as a spot treatment not to exceed 25% of a landowner's acreage in any given watershed in a single season.
Site of action Group 4: synthetic auxin
Chemical family Pyridine