2011 Basics of Weed Control

J.T. Brosnan, Ph.D. T.J. Samples, Ph.D.

UT Lifetime Learning Program February 18th, 2010

Knoxville, TN

Identification

http://www.tennesseeturfgrassweeds.org

http://www.tennesseeturfgrassweeds.org

http://www.tennesseeturfgrassweeds.org

Wild Garlic

Perennial from bulb Hollow, cylindrical stems

Foliage aromatic when crushed

 Sob pic

Star of Bethlehem

Perennial from bulb Hollow stems

Foliage NOT aromatic when crushed

White mid-rib

Henbit

Square Stem

Hairy

No Petiole on Upper Portions

 Henbit, deadnettle pics

Purple Deadnettle

Petioles

Purple in color when mature

 Chickweed pic

Common Chickweed

Wet, shady areas Egg shaped leaves

Mouse-ear Chickweed

 Rough, athletic fields, home lawn

Annual Bluegrass

Photo by Bob Raley

Photo by Bob Raley

What are the products?

TRADE NAME

ACTIVE INGREDIENT

What are the products ?

TRADE NAME ACTIVE INGREDIENT

What Now???  Glyphosate (Roundup)

•  < 1 pt/A as broadcast •  COMPLETELY DORMANT BERMUDAGRASS •  Combine with PRE??

 Phenoxy herbicides •  Three-Way/Weed-B-Gone on TF and B •  Dismiss for SOB

 No poa products for homeowners  Revolver for LCOs on B

Spot Treatments

Follow the label 1-1.5% solution

WILL KILL DESIRABLE VEGETATION

Preemergence Crabgrass Control

Photo by: D.F. Lewis

Photo by: D.F. Lewis

Smooth Crabgrass

Hairy Crabgrass

PREEMERGENCE

PREEMERGENCE

BEFORE

PREEMERGENCE

BEFORE YOU CAN SEE IT

 Soil temp ≥55°F for 3 consecutive days and nights

All PRE products effective

(>90% control) in 2010 for up to

100 days after application

What are the products? TRADE NAME ACTIVE INGREDIENT

Dimension

Pendulum

Barricade

Ronstar

dithiopyr

pendimethalin

prodiamine

oxadiazon**

Formulations

At least ½” irrigation within 24 hrs of application

 Seeding pic

DO NOT APPLY IF YOU PLAN TO SEED

I missed my

crabgrass timing!!!!

 Dimension  Tenacity

 Acclaim Extra  Fusilade II  Drive XLR8  MSMA  MSMA + Sencor

Cultural Practices to Increase Turf Density

AIR

Fertility  Bermudagrass lawns

•  1 lb N/1000 sq. ft •  Every month of growing season

 Tall fescue lawns • ½ lb N/1000 sq. ft.  APRIL, MAY

•  1 lb N/1000 sq. ft.  SEPTEMBER, OCTOBER, NOVEMBER

With Nitrogen Without Nitrogen

Photo Courtesy of M.J. Schlossberg

MOW, MOW, MOW !!

Indicator Weeds

Goosegrass

Prostrate Knotweed

Good Balance of Air and Water

Improve Soil Conditions

Move the Traffic Pattern

clover White Clover

Nutsedge  Bermuda infestation pic

Yellow Nutsedge

Install Drainage ?

Over Irrigating ?

Summary  Identification  Product Selection  Cultural Practices  Indicators

 Resources

http://www.tennesseeturfgrassweeds.org

http://www.tennesseeturfgrassweeds.org

http://www.tennesseeturfgrassweeds.org

http://www.tennesseeturfgrassweeds.org

http://www.tennesseeturfgrassweeds.org

Questions?