Weed Management Handbook

2,4-D amine

Rate Spot treatment: 0.25 to 0.5% solution

Time Apply in spring to fully-grown leaves but prior to flowering.

Remarks 2,4-D is usually not able to fully control common fennel, so combining with other products is generally recommended. Retreatment will likely be necessary.

aminopyralid (Milestone)

Rate 1 to 1.75 oz ae/A (4 to 7 fl oz/A)

Time Apply preemergence in winter to early spring, or in spring to actively growing plants before the bud stage of growth.

Caution Do not let spray drift onto desirable vegetation. Many forbs (desirable broadleaf plants) can be seriously injured or killed. Do not exceed 7 fl oz/A Milestone per year.

aminocyclopyrachlor + chlorsulfuron (Perspective)

Rate 4.75 to 8 oz/A

Time Apply to seedlings in spring when plants are actively growing.

Remarks Adjuvants can be used; these include methylated seed oils 0.5 to 1% v/v, nonionic surfactants at 0.25 to 1% v/v, and crop oil concentrates at 1%v/v.

Remarks Although PNW data are lacking, some reports suggest glyphosate at 2% is effective.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted

2,4-D

Rate 0.95 to 1.9 lb ae/A (2 to 4 pints/A)

Time Apply to seedlings in spring when plants are growing rapidly.

Remarks Good coverage is necessary to achieve control.

Caution Do not drift to sensitive crops.

Site of action Group 4 synthetic auxin

Remarks Although PNW data are preliminary, imazapyr, picloram, and glyphosate appear promising in initial trials.

Site of action (imazapyr) Group 2: acetolactate synthase (ALS) inhibitor; (glyphosate) Group 9: inhibits EPSP synthase; (picloram) Group 4: synthetic auxin

Chemical family (imazapyr) imidazolinone; (glyphosate) none generally accepted; (picloram) pyridine

aminocyclopyrachlor + chlorsulfuron (Perspective)

Rate 4.75 to 8 oz/A

Time Apply to sulfur cinquefoil in the pre-bud stage of growth.

Remarks Adjuvants can be used; these include methylated seed oils 0.5 to 1% v/v, nonionic surfactants at 0.25 to 1% v/v, and crop oil concentrates at 1% v/v.

aminocyclopyrachlor + chlorsulfuron (Perspective)

Rate 1.2 to 1.8 oz/A aminocyclopyrachlor + 0.5 to 0.7 oz/A chlorsulfuron (3 to 4.5 oz/A of product)

Time Apply to actively growing vegetation.

clopyralid (Transline)

Rate Spot treatment: 0.5% solution.

Time Apply to actively growing vegetation.

Remarks Mix with 0.25% by volume nonionic surfactant and apply to all exposed foliage. Repeat applications may be required to achieve full control.

aminocyclopyrachlor + metsulfuron (Streamline)

Rate 7.5 to 11.5 oz/A

Time Apply to actively growing vegetation.

Remarks Adjuvants can be used; these include methylated seed oils 0.5 to 1% v/v, nonionic surfactants at 0.25 to 1% v/v, and crop oil concentrates at 1% v/v.