Weed Management Practices for Sports Fields

Weed Management Practices for Sports FieldsAlec KowalewskiTurfgrass Specialist Oregon State University alec.kowalewski@oregonstate.edu

Weed Management Practices for Sports Fields• Integrated Pest Management (IPM)

• Primary Cultural Practices • Mowing • Fertilization• Irrigation

• Cultivation and inter-seeding

• Management of…• False dandelion • White clover • Annual bluegrass

Primary Cultural Practices

1. Mowing2. Fertilizing 3. Irrigation

Primary Cultural Practices

Ferti

lizer

Mow

ing

Irrigation

Turfgrass

Primary Cultural Practices

Mow

ing

Irrigation

Primary Cultural Practices

Turfgrass

Mowing

Irrigation

Primary Cultural Practices

Turfg

rass

Ferti

lizer

Mow

ing

Irrigation

Turfgrass

Primary Cultural Practices

MOWING

6”

4”

4.5”

3” 3”

2”1.5”

1”

Des

ired

Mow

ing

Hei

ght

Mow

ing

foll

owin

g 1

/3 R

ule

Mowing• The one-third rule

Mowing • The one-third rule

Mowing• The one-third rule• Prevent scalping

• Scalping…• Causes a brown appearance• Stops growth and development• Depletes carbohydrates• Makes turf susceptible to environmental stress

Sunlight

4”

Sunlight

3”

Mowing • The one-third rule• Prevent weed seed germination

Mowing

Sunlight Sunlight

4”

2”

• The one-third rule• Prevent weed seed germination

Mowing• Raise your mowing height• Adhere to the one-third rule• Improve rooting

Mowing• Raise your mowing height• Prevent weed seed germination

Sunlight Sunlight

4”

2”

Mowing• Raise your mowing height

• Raising the height from 1.5” to 3.0”• Improved turfgrass quality • Reduced weed populations• Crabgrass cover by up to 52% • Dandelion populations by up to 45%• White clover by up to 58%

Kentucky bluegrass, perennial ryegrass and fine fescue mixture

Mowing

Ragweed Garlic mustard

• Increase your mowing frequency • Adhere to the one-third rule • Increase turfgrass density• Weed control

• Lambsquarter• Ragweed• Purslane• Garlic mustard

Mowing

35 days

• Increase your mowing frequency • Adhere to the one-third rule • Increase turfgrass density• Weed control

• Lambsquarter• Ragweed• Purslane• Garlic mustard

Mowing

42 days

• Increase your mowing frequency • Adhere to the one-third rule • Increase turfgrass density• Weed control

• Lambsquarter• Ragweed• Purslane• Garlic mustard

Mowing

49 days

• Increase your mowing frequency • Adhere to the one-third rule • Increase turfgrass density• Weed control

• Lambsquarter• Ragweed• Purslane• Garlic mustard

Mowing • Weeds that indicate your mowing height is to low…• Annual bluegrass• Crabgrass • Dandelion

Crabgrass

Annual bluegrass

MOWING

FERTILIZATION

Fertilization• Select a fertilizer designed for turfgrass• Primary nutrient (N-P-K)

• High N• Low P• 10:1

Fertilization• The holiday plan• 3-5 lbs N 1000 ft2 year

• Memorial day • 1.0-1.5 lbs N 1000 ft2

• 4th of July • 0.5-1.0 lbs N 1000 ft2

• Labor day• 0.5-1.0 lbs N 1000 ft2

• Thanksgiving• 1.0-1.5 lbs 1000 ft2

Fertilization• The holiday plan• Cool-season turfgrass species

• Kentucky bluegrass• Perennial ryegrass• Fine fescue• Tall fescue

Fertilization

Fertilization • Low fertility weeds include…• White clover• Plantain • Black medic

White clover

PlantainBlack medic

FERTILIZATION

IRRIGATION

Irrigation • Adjust your rates with the seasons • Spring

• 0.0-0.75 inch week• Summer

• 0.75-1.5 inch week• Fall

• 0.0-0.75 inch week

Irrigation• Check your rates• 20 minutes

• 0.1 inch• 0.25 inch• 0.5 inch

Irrigation• Twice as much is not twice as good• Moss

Irrigation• Twice as much is not twice as good• Increased disease incidence

Dollar spot Pythium blight Brown patch

• Twice as much is not twice as good• Leaching pesticides and fertilizers• Waste of water and money

Irrigation

• Weeds associated with drought conditions… • Summer annuals

• Knotweed • Wood sorrel • Crabgrass

Irrigation

Crabgrass

Knotweed woodsorrel

Irrigation • Weeds associated with over irrigation…• Annual bluegrass• Rough bluegrass

Rough bluegrass

Annual bluegrass

IRRIGATION

CULTIVATION & INTER-SEEDING

Cultivation• What is your objective when cultivating the turfgrass?

Cultivation• Objectives • Relive compaction

• Improves gas exchange and drainage• Remove organic matter

• Decreases potential for disease• Improves drainage

• Prepare for seeding• Ensures seed to soil contact

Cultivation

Cultivation

Cultivation • Annual weeds • Annual bluegrass (winter annual)• Crabgrass (summer annual)• Purse lane (summer annual)• Knotweed

Cultivation • Annual weeds • Annual bluegrass (winter annual)• Crabgrass (summer annual)• Purse lane (summer annual)• Knotweed

Summer annual germination

Cultivation • Annual weeds • Annual bluegrass (winter annual)• Crabgrass (summer annual)• Purse lane (summer annual)• Knotweed

Cultivation • Annual weeds• Pre-emergent herbicides

• Non-selective • Pendulum (a.i. pendimethalin)

• $54/54,000 sq ft

• Selective • Tupersan (a.i. siduron) • Tenacity (a.i. mesotrione)

• $98/54,000 sq ft

• Inter-seeding • $1,440/54,000 sq ft

• 600 lbs

Knotweed – Summer annual

Fall – After 1st frost

Non-selective pre-emergent herbicide. Applied in the spring.

No inter-seeding.

Cultivation • Annual weeds• Pre-emergent herbicides

• Non-selective • Pendulum (a.i. pendimethalin)

• $54/54,000 sq ft

• Selective • Tupersan (a.i. siduron) • Tenacity (a.i. mesotrione)

• $98/54,000 sq ft

• Inter-seeding • $1,440/54,000 sq ft

• 600 lbs

Knotweed – Summer annual

Fall – After 1st frost

Non-selective pre-emergent herbicide. Applied in the spring.

No inter-seeding.

Inter-seeding • Perennial ryegrass• Growth habit

• Bunch type

• Germination • 7 to 10 days

• Inter-seeding rate• 8 to 11 lbs/1,000 sq ft

CULTIVATION & INTER-SEEDING

WEED MANAGEMENT

Weed Management • Common turf weeds…• 1. false dandelion• 2. white clover • 5. annual bluegrass

False dandelion White clover Annual bluegrass

FALSE DANDELION

False dandelion• Scouting and ID • Perennial weed • Spring seeding • Drought tolerant

False dandelion• Post emergence herbicides (curative)• 3-way broadleaf herbicide

• 2,4-D• MCPP• Dicamba

Common dandelion Broadleaf plantain Sow thistle

False dandelion

• Apply in the fall (October 4 = 10/4 Good Buddy)

False dandelion

• Apply in the fall (October 4 = 10/4 Good Buddy)

False dandelion

False dandelion• Follow up applications… • Apply and then apply again 2-4 weeks later

Effects of Defendor and Dimension on catsear dandelion in perennial ryegrass, observed 8 weeks after Spring treatment in Corvallis. OR on July 2, 2013.

• **Trt 6. Rotation:• 1st app Dimension 2 EW + Defendor (1.0 + 0.25 pt/A)• 2nd app Dimension 2 EW + Trimec Classic (1.0 + 4.0 pt/A)

Trt Treatments*% Weed Control

8 WAT1 Dimension 2 EW 0.02 Dimension 2 EW + 4Wks 0.03 Defendor 93.94 Defendor + 4 wks 100.05 Dimension 2 EW + Defendor 93.36 Rotation (See Below)** 100.07 Trimec Classic + Dimension 2 EW + 4 Wks 100.08 Trimec Classic 92.59 Untreated 0.0

LSD 4.6

Effects of Defendor and Dimension on catsear dandelion in perennial ryegrass, observed 8 weeks after Spring treatment in Corvallis. OR on July 2, 2013.

• **Trt 6. Rotation:• 1st app Dimension 2 EW + Defendor (1.0 + 0.25 pt/A) • 2nd app Dimension 2 EW + Trimec Classic (1.0 + 4.0 pt/A)

Trt Treatments*% Weed Control

8 WAT1 Dimension 2 EW 0.02 Dimension 2 EW + 4Wks 0.03 Defendor 93.94 Defendor + 4 wks 100.05 Dimension 2 EW + Defendor 93.36 Rotation (See Below)** 100.07 Trimec Classic + Dimension 2 EW + 4 Wks 100.08 Trimec Classic 92.59 Untreated 0.0

LSD 4.6

FALSE DANDELION

WHITE CLOVER

White clover• Perennial weed• Nitrogen deficient soil• White flower • Circular leaves

White clover• Post emergence herbicides (curative)• Triclopyr • Fluroxypyr• 2,4-D + triclopyr

Chickweed English daisy Wild violet

White clover

• Apply in the fall (October 4 = 10/4 Good Buddy)• Apply and then apply again 2-4 weeks later

False dandelion

WHITE CLOVER

ANNUAL BLUEGRASS

• Initiated Summer 2010• Lewis Brown Turf Farm, Corvallis, OR

Spreading ryegrass trial

• Seeding date: June 15, 2010 • Seeding rate: 6 lbs/1,000 ft2

• Fertility rate: 4 lbs N/1,000 ft2

Spreading ryegrass trial

• Mowing height • 0.625”• 1.25”• 2.0”

Spreading ryegrass trial

Annual bluegrass encroachment‘SR 4600’

‘Fiesta 4’

‘Natural Knit’

‘RPR’

0.625”

Lorenz Soccer Field, Corvallis, OR

‘SR4600’ maintained at 0.625”. Seeded 2011.

Lorenz Soccer Field, Corvallis, OR

‘SR4600’ maintained at 0.625”. Seeded 2011.

Some preemergence herbicides effective on annual bluegrass include…

Common name active ingredientPendulum pendimethalin

Prograss ethofumesateBalan benefin

Bensumec bensulideDimension dithiopyr

Quali-Pro Prodiamine prodiamine

Product Cost of Product

Apps Total

Pendulum $54.00 2 $108.00Prograss $297.00 3 $891.00

Grand Total $999.00

Estimated costs of a Pre/Postemergence Chemical Control Program of Annual bluegrass on a 54,000 ft2 field. It is important to note that cost can vary considerably according to product and control is often variable.

OSU Softball Complex, Corvallis, OR

Mixed stand of perennial ryegrass and annual bluegrass, 10 years plus

OSU Softball Complex, Corvallis, OR

Mixed stand of perennial ryegrass and annual bluegrass, 10 years plus

OSU Softball Complex, Corvallis, OR

Mixed stand of perennial ryegrass and annual bluegrass, 10 years plus

Annual bluegrass encroachment

Lorenz field Seeded 2011

OSU Softball Seeded 2000

Annual bluegrass encroachment

Lorenz field Seeded 2011

OSU Softball Seeded 2000

Weed Management Practices for Sports FieldsAlec KowalewskiTurfgrass Specialist Oregon State University alec.kowalewski@oregonstate.edu