WEED CONTROL

Herbicide Residue

Stinger (clopyralid) and Curtail (clopyralid plus 2,4-D) may have
a herbicidally active residue in the soil following POST appli-
cation. Rotational crop restrictions for Stinger and Curtail are
found on page 64 of the 1996 North Dakota Weed Control Guide in
the table, "Rotation Restrictions for Crops Grown in North
Dakota". Pea, lentil, potato, and broadleaf crops grown for seed
can be planted 18 months after Stinger or Curtail application.
The potential for injury from soil residue of Stinger or Curtail
can be reduced by burning, removal, or incorporation of treated
crop residues.

Tordon (picloram) at 0.0156 lb/A active ingredient (1 fl oz/A)
may carryover in the soil for more than one crop year. Only grass
or grain crops such as grass, small grains or flax should be
planted on fields treated with picloram the previous year.
Sunflower, soybean, dry edible bean, and potato are especially
susceptible to Tordon.

(Submitted by Richard K. Zollinger, Extension Weed Specialist)