Pasture and Hay Field Weed Management

Dr. Tim Murphy, Extension Weed Specialist

The University of Georgia

Forage Weed Issues

Lack of management - fertility, lime, mowing, overgrazing

No weed control - only 15% of Georgia pastures are sprayed on annual basis

Grazing and haying restrictions Weedy grass control in hay fields and legume tolerance

Do I spray or fertilize first?

Spray first Control existing weeds Begin soil-test based lime and fertilizer program Establish legumes after good weed control has been

practiced for 1 to 2 years

When do you spray?

Winter annuals - henbit, chickweed, buttercups, thistlesNovember through March

Summer annuals - spiny amaranth, bitter sneezeweedApril through mid-July

Perennialsgrowth stage dependent

Herbicide Options 2,4-D dicamba (Vanquish, Banvel) 2,4-D + dicamba (WeedMaster) dicamba+ diflufenzopyr (Overdrive) triclopyr (Remedy) 2,4-D + triclopyr (CrossBow) triclopyr + clopyralid (Redeem) 2,4-D + picloram (Grazon P+D) fluroxypyr + picloram (Surmount) fluroxypyr + triclopyr (Pasturegard)

Herbicide Options (cont.) diuron (Direx, Diuron) metsulfuron (Cimarron) metsulfuron + 2,4-D + dicamba (Cimarron MAX) hexazinone (Velpar) tebuthiuron (Spike) paraquat (Gramoxone Extra) glyphosate (Roundup UltraMax) imazapic (Plateau) (no longer an option)

Remedy 4.0 lbs./gal. triclopyr ester low volatile - but ?????? Excellent on upright blackberry, numerous broadleaf weeds Good on tropical soda apple Fair on horsenettle Poor on pokeweed, honeysuckle, trumpetcreeper Expensive

Remedy

Mixes with diesel Remedy 20% + 80% diesel, excellent as basal

application for trees < 4 inch DBH, and spot control of pricklypear cactus and palmetto

Injurious to clovers Apply to seedling grasses 5 to 6 inches tall or after tiller

development

Remedy

Grazing and haying restrictions

Beef grazing - 0 d Dairy grazing - 14 dHay - 7 d (all livestock types, except lactating dairy cattle,

365 d)Slaughter - 3 d

Redeem

2.25 lbs./gal. triclopyr amine + 0.75 lbs. clopyralid amine

Excellent control aster and legume weeds Rates: 1.5 to 4.0 pts./acre Highly injurious to legumes Alternative to Crossbow, WeedMaster, Grazon P+D

Redeem

Beef and other livestock grazing - 0 d Dairy grazing - 14 d

Hay - 7 d (all livestock types, except lactating dairy cattle, 365 d)

Slaughter - 3 d

New Products -2005 PastureGard - fluroxypyr + triclopyr (Remedy)

Broader weed spectrum than triclopyr alonecontrols annual, perennial, & woody species; enhanced

control of blackberry and dogfennel

Surmount – fluroxypyr + picloramBroader weed spectrum than fluroxypyr alonecontrols annual, perennial, & woody species

PastureGard

1.5 lbs./gal. triclopyr ester + 0.5 lbs./gal. fluroxypyr ester

Controls numerous brush species and broadleaf weeds.Upright blackberry, sweet gums, Sericea lespedeza,

dogfennel, gallberry, rose species, lantana Palmetto and yucca – use 2.0% v/v solution in waterFair control of horsenettle and tropical soda apple

PastureGard

Mixes with diesel and other oil carriers PastureGard 50% + 50% diesel, excellent as basal

application for trees < 4 inch DBH Injurious to clovers Apply to seedling grasses after tiller development

PastureGard

Beef and other livestock grazing - 0 d Dairy grazing – not permitted during the growing

season of application Hay – 14 d (all livestock types)

Reseeding Restrictions – PastureGard

Cool-season grasses and small grains - 21 days Clover and other legumes – 30 days Other crops – 120 days

Surmount 1.19 lbs./gal. picloram amine + 0.96 lbs. gal. fluroxypyr amine Controls broadleaf weeds, horsenettle, tropical soda apple, and

pricklypear cactus. Apply 3 to 4.0 pts./acre for prickly pear cactus in fall months,

control is very slow, about 2 yrs. About 30 d residual control Excellent control of upright-growing blackberry (3 to 4

pts./acre)

Surmount

Injurious to clovers Apply to seedling grasses or overseeded small grains at tiller

growth stage Newly-sprigged bermuda –delay until stolons are 6 inches long Beef grazing - 0 d; slaughter 3 d Lactating Dairy Animals – grazing 14 d; silage 14 d. Hay – 7 d (all livestock types)

Reseeding Restrictions – Surmount

Cool-season grasses - 21 days Clovers – 12 months Other legumes – 12 months

Surmount- It’s Good - BUT!!!!!

Do notuse hay from treated areas for compost or mulchtransfer livestock to untreated areas without 7 d cleanoutuse manure for fertilizing broadleaf cropsuse in any temporary forage system involving broadleaf crops

USE ONLY ON PERMANENT GRASS FORAGE SYSTEMS

Grazon P+D

2.0 lbs./gal. 2,4-D amine + 0.54 lbs./gal. picloram amine Excellent control of broadleaf weeds Excellent on horsenettle and tropical soda apple For horsenettle, use 3 pts./acre at early bloom. About 30 d residual control Fair control of blackberry

Grazon P+D Injurious to clovers Apply to seedling grasses or overseeded small grains at

tiller growth stage, 1.5 pts./acre or less Newly-sprigged bermuda – 1.5 pts./acre, delay until

stolons are 6 inches long Beef grazing - 0 d Dairy grazing - 7 d

Hay - 30 d (all livestock types)Slaughter - 3 d

Reseeding Restrictions – Grazon P+D Cool-season grasses - 21 days Clover - 2 pts./acre or less

Fall-seeding permitted if Grazon P+D applied no later than June (4 month plant back)

Clover – 2 to 3 pts./acreSpring (Feb. – Mar.) seeding permitted the following spring

for applications made no later than Sept. 15 the previous year.

Grazon P+D - It’s Good - BUT!!!!! Do not

use hay from treated areas for compost or mulchtransfer livestock to untreated areas without 7 d cleanoutuse manure for fertilizing broadleaf cropsuse in any temporary forage system involving broadleaf crops

USE ONLY ON PERMANENT GRASS FORAGE SYSTEMS

Cimarron

60DF metsulfuron DuPont is phasing out Ally Effective for ‘Pensacola’ bahiagrass, spiny amaranth,

curly dock, buttercup, wild garlic control, blackberry Poor horsenettle control Injurious to legumes & ryegrass (4 mo plant back)

Cimarron

Now labeled at 0.1 to 1.0 oz. product per acre Use low rates on tall fescue and timothy Do not mix with liquid fert. for bahiagrass control 0 d grazing or haying restriction - all livestock

Cimarron MAX

Co-Pack product Metsulfuron 60DF + 2,4-D amine (2.87 lbs./gal.) +

dicamba (1.0 lb./gal.) Increases number of broadleaf weeds controlled Use rates 0.25 to 1.0 oz./acre of Cimarron plus 1.0 to

4.0 pts./acre of 2,4-D + dicamba Add nonionic surfactant at 0.25% v/v

Plateau

BASF will no longer market to private landowners grass roadsides, wildflowers, noncropland sites WHY???

EconomicsLow sales,objections to injuryCan make more money in other markets

Newly-sprigged Bermuda Direx 4L, Diuron 4L Karmex is not labeled for this use Plant sprigs 2 inches deep Apply immediately after sprigging Use 3.0 to 4.0 pts./acre Not labeled in established bermudagrass Annual grasses and broadleaf weeds

Overdrive - BASF

Dicamba + diflufenzopyr Controls broadleaf weeds 0 day grazing or haying restriction Limited data base Primarily will be marketed for rights-of-way use

Summary - Forage Weed Control

Know cropping system Use approved cultural practices Identify weeds Select product Follow grazing and haying restrictions Proper application timing