Posts Tagged ‘hay & pasture weed control’

Fall Weed Control in Pastures and Hay

Friday, August 31st, 2012

Quintin Johnson, Extension Associate, Weed Science; quintin@udel.edu

Fall provides an excellent opportunity for perennial weed management in pasture and hay with herbicide applications. Most herbicides labeled for use in pasture are translocated, or moved, to various parts of the plant. As fall approaches, perennial weeds like curly dock, Canada thistle, horsenettle, pokeweed, and others are beginning to replenish stored carbohydrates in root structures to prepare for over-wintering and new spring growth. Translocated herbicides are able to reach the rooting structures more efficiently during this period, thus providing more effective perennial weed control. However, if weeds are drought-stressed, herbicide translocation may be slower or incomplete, resulting in less effective control. Delay herbicide applications until after you receive adequate rainfall. Fall applications should be made at least 7 to 10 days before a mowing for greatest effectiveness. In well established perennial weed populations, multiple years of good weed control will be needed to significantly reduce the rootstock of perennial weeds.

There are several things that must be considered when choosing an herbicide for pastures or hay fields including: forage species grown; weed species present; risk of herbicide contact with desirable plants through root uptake, drift, or volatility; residues in composted straw or manure; herbicide rotational, over-seeding, grazing, or harvest restrictions; and cost. Be sure to follow all precautions and restrictions on herbicide labels.

The “Pasture and Hay Weed Management Guide” for Delaware is available from the University of Delaware Cooperative Extension. Access a pdf version on-line at http://www.rec.udel.edu/weedscience/WS_ManagementGuides.html.

Updated Weed Control Guides are Available – And They’re Free

Thursday, April 5th, 2012

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Available from your county Extension office are weed management guides for assistance in weed control in corn, soybeans, or forages. There is a separate guide for each commodity. The first half of the corn and soybean guides deals with soil-applied herbicides and the second half is for postemergence herbicides. These guides include information on pre-mixes and what is in the pre-mix, expanded weed control tables, information on application timing, comments for each of the herbicides, and much more. The forage guides cover alfalfa as well as grass forages. Contact your county extension office for these free guides. Or find them at the UD-REC website: http://www.rec.udel.edu/weedscience/WS_ManagementGuides.html.

Weed Control for Grass or Mixed Pasture Plantings

Friday, August 28th, 2009

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Weed control options are very limited for establishing a grass or mixed stand pasture. There are no products to use pre-plant incorporated or preemergence that will provide residual control and not injure the crop. Early postemergence options are also very limited. Ally, Banvel, Overdrive, Crossbow, or 2,4-D can be used for pure grass seedlings (they will kill clovers and alfalfa) but grasses need to be well established at time of application. Ally can injure fescue and ryegrass. Fescue injury can be reduced if Ally is tankmixed with 2,4-D.

Fall Weed Control in Pastures and Hay

Friday, September 19th, 2008

Quintin Johnson, Extension Associate – Weed Science; quintin@udel.edu

Fall provides an excellent opportunity for perennial weed management with herbicide applications. Most herbicides labeled for use in pasture are translocated, or moved to various parts of the plant. As fall approaches, perennial weeds like curly dock, Canada thistle, horsenettle, pokeweed, and others are beginning to replenish stored carbohydrates in root structures to prepare for over-wintering and new spring growth. Translocated herbicides are able to reach the rooting structures more efficiently during this period, thus providing more effective perennial weed control. However, if weeds are drought-stressed, herbicide translocation may be slower or incomplete, resulting in less effective control. Delay herbicide applications until after you receive adequate rainfall. Fall applications should be made at least 7 to 10 days before a mowing for greatest effectiveness. In well established perennial weed populations, multiple years of good weed control will be needed to reduce significantly the rootstock of perennial weeds.

There are several things that must be considered when choosing an herbicide for pastures or hay fields including: forage species grown; weed species present; risk of herbicide contact with desirable plants through root uptake, drift, or volatility; residues in composted straw or manure; herbicide rotational, over-seeding, grazing, or harvest restrictions; and cost. Consult your local cooperative extension agent or industry representative for help with these considerations, and be sure to follow all precautions and restrictions on herbicide labels.

The “Pasture and Hay Weed Management Guide” for Delaware is available from University of Delaware Cooperative Extension. Contact your local county agent for a printed copy, or access a pdf version on-line at http://www.rec.udel.edu/weed_sci/WeedPublicat.htm.

Milestone Does Not Have a Fit in Most Pasture Situations

Friday, September 19th, 2008

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Milestone (aminopyralid) is a relatively new herbicide for pastures and CRP that provides good to excellent control of many broadleaf weeds (including thistles). It has other positives as well that makes it a very tempting choice for grass pastures. However, the herbicide does not break down in the plants, or in the digestive tract of the animals, nor during the composting process. Therefore, manure from animals fed with treated hay or grazed in the treated pastures, can contain some of the active herbicide. In addition, if this manure is applied to fields or gardens with sensitive plants, they can be severely injured or killed. Broadleaf plants (especially legumes) are most prone to injury.

The following is from the Milestone label:

Do not use Milestone-treated plant residues, including hay or straw from treated areas, or manure from animals that have grazed forage or eaten hay harvested from treated areas within the previous 3 days, in compost or mulch that will be applied to areas where commercially grown mushrooms or susceptible broadleaf plants may be grown.

Do not spread manure from animals that have grazed or consumed forage or eaten hay from treated areas within the previous 3 days on land used for growing susceptible broadleaf crops.

Manure from animals that have grazed forage or eaten hay harvested from Milestone-treated areas within the previous 3 days may only be used on pasture grasses, grass grown for seed, and wheat.

Do not plant a broadleaf crop in fields treated in the previous year with manure from animals that have grazed forage or eaten hay harvested from Milestone-treated areas until an adequately sensitive field bioassay is conducted to determine that the Milestone concentration in the soil is at level that is not injurious to the crop to be planted.

Milestone is better suited in our region for use with CRP where the grasses are not harvested or grazed. Since manure management is essential to protect sensitive plants, it has no fit in pastures or hay crops in our area.