Herbicides for corn after any crop in established birdsfoot trefoil/crownvetch groundcover

Table 4. Herbicides for corn after any crop in established birdsfoot trefoil/crownvetch groundcover.

See specific product label to determine correct rate for the soil type and weed species found in individual fields.

Herbicide	No.	Product/A	lb ai/A	Remarks	Weeds Controlled
Gramoxone Max 3S (paraquat) plus	10	1 to 2 pt plus	0.375 to 0.75 lb plus	Read the label. Use flat-fan nozzle with 20 to 30 psi pressure for best results. Weak on established biennial and perennial weeds including dandelion. Safe on 1-year-old birdsfoot trefoil and crownvetch.	Annual grasses and broadleaved weeds plus top kill only of biennial and perennial weeds.
nonionic surfactant; can be tank-mixed with treatments 12, 13, 14, or 15 when applied before corn emergence.		1 pt/100 gal	label rate
Roundup 4S (glyphosate) or	11	1 pt or	0.5 lb or	Read the label. Apply when dandelion ae in full bloom. Use flat-fan nozzle. Annual weeds may be any size. Established weeds should have 6 to 8 inches of leafy growth. Apply at least four days beore planting in 5 to 10 gallons of water.	Top and root kill of most established biennial and perennial weeds; provides good suppression of crownvetch but poor suppression birdsfoot trefoil.
Touchdown IQ (sulfosate) plus		1 pt plus	0.5 lb plus
NIS if needed. Can be Tank mixed with treatments 12, 13, 14, or 15 and applied before corn emergence if burndown is needed.		2 qt/100 gal.	label rate
Pre or Early Postemergence treatments to the weeds and/or cover crop and corn; don't include Roundup, Touchdown or Gramoxone if corn has emerged.
Lightning 70DG plus	12	0.768 oz plus	0.0336 lb plus	Read the label. Plant Pursuit tolerant IT corn varieties only with relative maturity greater than 88 days. May be applied pre or early post (spike stage) of corn. Add dicamba for common burdock, Canada thistle, curly dock, or goldenrod after they have 4–6" of new growth.	Annual grasses and broadleaves; TR pigweed and lambsquarters, dandelion, and most other broadleaved perennials; suppression of yellow nutsedge.
Basis Gold plus		5.6 oz plus	0.3131 lb This is about a half rate of each. add 0.25 lb
nonionic surfactant plus		1 qt/100 gal plus
Nitrogen solution for Per. brodleaved weeds add Banvel or Clarity		2 gal/100 gal add 0.5 pt
Bicep II or Bicep Lite II plus	13	1 qt or 2 qt plus	1.475 lb or 2.45 lb plus	Read the label. Plant any corn variety with relative maturity greater than 88 days. Apply preemergence or early post. Basis works best on emerged weed seedlings 1 to 2 inches in height. Add dicamba for common burdock, Canada thistle, curly dock or goldenrod after they have 4-6" of new growth.	Birdsfoot trefoil and crownvetch suppression; annual grasses and broadleaves, TR pigweed and lambsquarters; no control of perennial broadleaved weeds without Banvel or Clarity.
Basis plus		0.25 oz plus	0.0117 This is less than a full rate of each. add 0.25 lb
nonionic surfactant plus		1 qt/100 gal. plus
Nitrogen solution. For perennial broadleaved weeds add Banvel or Clarity.		2 gal/100 gal add 0.5 pt.
Pursuit Plus plus Bicep II or Bicep Lite II plus	14	1.25 pt. plus 1 qt. or 2 qt. plus	0.453 plus 1.475 lb or 2.45 lb plus	Read the label. Plant Pursuit tolerant IT or Clearfield corn varieties only. Plant corn at least 1.5 inches deep. Apply late preemergence or early post to reduce the risk or injury form the pendimethalin in Pursuit Plus. Add dicamba for common burdock, Canada thistle, curly dock or goldenrod after they have 4-6" of new growth.	Birdsfoot trefoil and crownvetch suppression; annual grasses and broadleaves, TR pigweed and lambsquarters; no control of perennial broadleaved weeds without Banvel or Clarity.
Basis plus		0.25 oz plus	0.0117
nonionic surfactant plus		1 qt/100 gal. plus
Nitrogen solution. For perennial broadleaved weeds add Banvel or Clarity.		2 gal/100 gal add 0.5 pt.	add 0.25 lb
Pursuit ECO-PAK (imazethapyr) plus	15	0.72 oz. plus	0.0315 lb plus	Read the label. Plant Pursuit-resistant corn varieties only. May be applied preplant, pre-, or postemergence. Best weed control if applied early post when weeds are less than 3 inches tall.	Annual broadleaves, grasses, and shattercane suppression; atrazine gets common ragweed.
Basis Gold plus		5.6 oz plus	0.3131 lb
nonionic surfactant plus		1 gal/100 gal plus	This is less than a full rate of each.
Nitrogen solution. For perennial broadleaved weeds add Banvel or Clarity.		2 gal/100 gal add 0.5 pt.	add 0.25 lb
Postemergence Treatments - For broadleaf weed control and suppression of the cover crop. Should be tank mixed with treatments 12, 13, 14 or 15 if crownvetch already has 3-6" of growth when sprayed.
Banvel or Clarity (dicamba) plus	16	0.5 pt plus	0.25 lb plus	Read the label. If used post to corn, do not apply dicamba when air temperature is above 85ºF and do not apply with surfactant or nitrogen solution unless tank mixed with at least a 4/10 rate of Basis to prevent excessive crownvetch suppression.	Use for control of TR pigweed, lambsquarters, other broadleaved weeds and/or BFT and crownvetch suppression.
Basis plus		0.125 oz plus	0.0117 lb
nonionic surfactant plus		1 qt/100gal plus
Nitrogen solution		2 gal/100gal
Use only on crownvetch that is well established.
Postemergence Treatments -- Cleanup treatment for TR pigweed, lambsquarters, and grasses.
Pursuit ECO-PAK plus	17	0.72 oz plus	0.0315 plus	Read the label. Plant Pursuit tolerant corn varieties only. Works best on emerged weed seedlings 1 to 2 inches in height.	Annual grasses and broadleaves, TR pigweed and lambsquarters; suppression of shattercane, and yellow nutsedge.
Basis plus		0.125 oz plus	0.0058
nonionic surfactant plus		1 qt/100 gal. plus
nitrogen solution		2 gal/100 gal
Basis or	18	0.25 oz or	0.0117 or	Read the label. This is less than the label rate. Higher rates are generally unnessary. Apply when weeds are no more than 1 to 2 inches in height and corn is from spike to 4-leaf stage.	Use Basis for annual grasses and broadleaves including TR lambsquarters; Basis Gold for BFT suppression.
Basis Gold plus		5.6 oz plus	0.358 lb
nonionic surfactant plus		1 qt/100 gal. plus
nitrogen solution		2 gal/100 gal
Post Emergence Treatments -- Cleanup treatment for some grasses.
Accent 75DF + nonionic surfactant or	19	0.67 oz + 1 qt/100 gal or	0.03125	Read the label. Applications should be made when shattercane or seedling or rhizome johnsongrass is 8 to 16 inches tall. Corn should be between 4 and 20 inches in height. May be applied with drop nozzles if corn is too tall. Do not use on non-IR corn that has been treated with the insecticide Counter.	Shattercane, seedling and rhizome johnsongrass, fall panicum, quackgrass, C. thistle, and dewberry. Very weak on common ragweed.
crop oil plus		1 gal/100 gal plus
nitrogen solution (May be used on IMI-tolerant corn varieties even with the insecticide Counter)		4 gal/100 gal
Post Emergence Treatments -- Cleanup treatment for yellow nutsedge and other weeds listed here.
Permit plus	20	2/3 to 1 oz plus	0.0312 to 0.0468	Read the label. Apply when corn is in spike to 2-ft stage. Works best on emerged but small weed seedlings. Post treatments are safer on emerged crownvetch or birdsfoot trefoil seedlings.	Yellow nutsedge, velvetleaf, common ragweed, and suppression of TR pigweed.
nonionic surfactant. May be tank mixed with any of the above treatments for control of target weeds.		1 qt/100 gal

This page was last modified on 2/20/2004

	Pursuit-tolerant (IMI/IT or Clearfield) corn is needed only if imazethapyr (Pursuit). Pursuit Plus, or imazethapyr + imazapyr (Lightning) herbicides are used.
	Gramoxone Max provides only 2 or 3 weeks suppression of birdsfoot trefoil and crownvetch.
	1 to 2 pr./A of Roundup 4S, Touchdown IQ or any other glyphosate herbicide applied when dandelion are in full bloom with any of the the following treatments should suppress well established crownvetch about the right amount. Glyphosate is weak on birdsfoot trefoil.
	Atrazine @ 0.5 to 0.75 lb/A is needed to supress birdsfoot trefoil.
	Be ready to suppress the birdsfoot trefoil and crownvetch with post treatments if they have grown more than 6 inches before the corn is in the 6-leaf stage. If birdsfoot trefoil or crownvetch begins to bloom, it has not been suppressed enough.