Grow more grass with weed control — 2X to 3X

Grow a pound of weeds, lose a pound of grass. Control a pound of weeds, gain a pound or more of usable forage.

It’s about that simple, say pasture experts. While a pound of grass may not sound like much, those pounds add up — usually doubling to tripling forage in trials.

Range & Pasture Steward over the years has reported many trials that demonstrate grass yield from pasture weed control. Those are summarized again below.

A 100 percent increase in grass per acre means you’ve doubled carrying capacity compared to your formerly weedy pasture. At 200 percent, that’s 3X carrying capacity.

In these calculations, we’re omitting two outliers where weed control produced 13 pounds and 10.5 pounds of grass for every pound of weeds controlled. Without those, the average is 1.5 pounds of grass per pound of weeds controlled.

One set of numbers in the table is instructive for timing. Look for the asterisks near the middle of the far-right columns.

In two consecutive years — one dry, one wet — Texas A&M AgriLife Extension specialists David Bade and Paul Baumann ran a series of weed control demonstrations. Among other things, they measured effects of different spray timing: early application on weeds 3 to 6 inches tall and late application on weeds 8 to 12 inches tall.

In wet years, early spraying yielded slightly more grass. In dry years, early spraying yielded substantially more.

Other weather factors here may be lost to time but notice that 2X to 3X grass production isn’t unusual.

 


  • Unfertilized bermuda grass gained 131% grass production as a result of weed control. 
  • Fertilized bermuda grass gained 284% grass production as a result of weed control. 

 

 

INCREASE IN GRASS PRODUCTION AS A RESULT OF WEED CONTROL WITH A HERBICIDE: 25 TRIALS

Forage Lb./A

State

Grass

Fertilized?

Treated

Untreated

Weeds Controlled

Grass Increase

Grass yield
per lb. of weeds
controlled

Grass Increase percent

Grass

Weeds

Grass

Weeds

MS

bermuda

Yes

2906

323

756

1717

1394

2150

1.50

284%

MS

bermuda

No

1920

213

830

1893

1680

1090

0.65

131%

MS

bermuda

Unknown

1937

141

692

1337

1196

1245

1.00

180%

AR

bermuda

Unknown

8086

82

2893

5445

5363

5193

0.97

180%

TX

Coastal

Yes

4069

25

2124

1960

1935

1945

1.00

92%

TX

Coastal/native

Yes

8323

0

2587

7452

7452

5736

0.77

222%

TX

Coastal/native

Yes

7610

1494

2587

7452

5958

5023

0.84

194%

TX

Coastal/native

No

4987

0

1385

4252

4252

3602

0.85

260%

TX

Coastal/native

No

4898

1266

1385

4252

2986

3513

1.00

254%

TX

Coastal/native

Yes

2142

209

645

1698

1489

1497

*1.00

*232%

TX

Coastal/native

Yes

881

333

645

1698

1365

236

**0.17

**37%

TX

Coastal/native

no

1330

202

377

1127

925

953

*1.00

*253%

TX

Coastal/native

No

477

377

377

1127

750

100

**0.14

**27%

TX

N midgrass

No

3969

0

1726

1572

1572

2243

1.40

130%

TX

Klein

No

7443

65

5103

975

910

2340

2.60

46%

TX

Klein

No

2200

140

830

1200

409

3382

8.20

107%

TX

OW bluestern

No

5075

18

2842

746

728

2233

3.00

79%

TX

N shortgrass

No

1900

265

1200

2400

2135

700

0.33

58%

TX

N shortgrass

No

2720

0

1060

3040

3040

1660

0.55

157%

TX

L bluestern

No

9700

0

3250

3200

3200

6450

2.00

198%

TX

Seed mix

No

4737

322

2800

1260

938

1937

2.00

69%

TX

bermuda

Unknown

4682

0

1391

253

253

3291

***13.00

237%

TX

bermuda

Unknown

4049

0

1391

253

253

2658

***10.50

191%

TX

bermuda

Yes

6738

0

469

4384

4384

6269

1.43

1337%

TX

bermuda

no

3886

0

50

1980

1980

3836

1.94

767%

*Early Application in a dry year

**Late Application in a dry year

***Outliers not included in yield calculations

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