Salt Cedar Control and Management with DuPont Herbicides

Salt Cedar Control and Management with DuPont

Herbicides

Jerry R. Pitts

DuPont Crop Protection

22407 N. Lake Village Dr.

Katy, TX 77450

Saltcedar, What is it?

• A member of the Genus Tamarix and the Tamarisk Family (Tamaricaceae)

• 7 species listed in Texas

• A very aggressive, water-loving, drought tolerant, salt tolerant, !@#$%^&* plant

Saltcedar, Where did it come from?

• Native to the Mediterranean region, central Asian and North African deserts

• Introduced by nurseryman in early 1800’s as an ornamental– First record is from Bartram’s nursery in

Philidelphia in 1828

• Later used as an erosion-control plant in New Mexico and reported to have escaped cultivation in 1870’s

Saltcedar, Estimated Extent

• 1920’s - 40-50,000 acres infested• 1965 - 930,000 acres infested• 1989 - 1,017,000 acres infested• 1998 – 1,610,000 acres infested

• 1973 estimate of 600,000 acres infesting West Texas alone

• Estimated to spread at the rate of 1-1.5% per year

Saltcedar distribution in the U.S.

Source: Plant Conservation Alliance, Alien Plant Working Group (August 1997). 

Saltcedar Characteristics

• Continuous seed production through wide range of environmental conditions throughout growing season.– Each plant capable of producing >500,000

seeds per season– Cross-pollinated by wind and self-

compatible when unavailable.• Vigorous vegetative reproduction,

especially following fire.– Above ground plant material can re-sprout– Root material can re-sprout– Aggressive crown re-sprouter

Saltcedar Characteristics

• Brittle stems, not easily drawn from ground

• Competes interspecifically by allelochemics due to salt-glands

• Facultative phreatophyte using 3-6 acre ft./year– High water user– Drought tolerant

Negative Impacts of Saltcedar on the Environment

• Widens floodplains by clogging stream channels• Increased channelization along rivers and streams• Increased fire and flood frequency• Increases sedimentation deposition• Crowds out native stands of riparian and wetland

vegetation• Increased water/soil surface salinity• Lowers wildlife habitat value• Dries up springs, wetlands, riparian areas and small

streams by lowering surface water tables

Criteria for successful saltcedar control program

1. Any control strategy must target the crown and root system of the plant

2. Herbicide must be applied when plant is most susceptible

3. Application technology should allow for complete coverage of the plant and penetration through dense canopy layers

4. Saltcedar control is not a one time job

Saltcedar Management Alternatives

• Aerial Herbicide Application

• Individual Plant Treatment with Herbicides

• Mechanical control strategies

• Biological control strategies

Biological Control

• Diorhabda elongata – leaf feeding bettle (China)

• Dr. Ray Carruthers- UDSA

Mechanical Control

• Physical Removal and Fire

• Costs Dependent Equipment and Labor Required

• Soil Disturbance and Re-Infestation

Individual Plant Treatment with Herbicides

Treatment Control Ratings-Brush*

Control Rating % of Plants Killed

Very High 76-100

High 56-75

Moderate 36-55

Low 0-35

*Chemical Weed and Brush Control Suggestions for Rangeland, Texas Cooperative Extension, B-1466, 4-05

IPT Herbicide Recommendations(TX A&M Extension)

1. Arsenal (Imazapyr) 1%

2. Arsenal (Imazapyr) + 0.5%Roundup (Glyphosate) 0.5 %

3. Arsenal (Imazapyr) + 0.5%Rodeo (Glyphosate) 0.5%

4. Remedy (Triclopyr)-Basal 25% in diesel

IPT Herbicide Recommendations(TX A&M Extension)

• Timing- July – Sept., or until leaves begin to turn yellow

• IPT- Throughly wet foliage

• Aerial or Ground Broadcast- Min. 10 gpa

• Add 1 to 2 qts surfactant per 100 gal water

• Note: Check Arsenal label for special restrictions on use related to endangered species and grazing restrictions.

• Arsenal alone and in combination with Rodeo or Roundup will cause damage to grasses, forbs and other desirable trees.

Aerial Herbicide Applications

Aerial Herbicide Recommendations

1. Arsenal (imazapyr) 4 pints/acre 1.0 lb. a.i.

2. Arsenal (imaz.) + 2 pints/acre 0.5 lb. a.i.

Roundup (gyphosate) 1 pint/acre 0.5 lb. a.i.

3. Arsenal (imaz.) + 2 pints/acre 0.5 lb. a.i.

Rodeo (glyphosate) ¾ pint/acre 0.5 lb. a.i.

Aircraft comparison:

Helicopter Airplane

Spray at 30 mph Spray at 110-140 mph

Flat turns Banked turns

15 GPA 10 GPA Max.

Varied spray width Fixed spray width

1000 micron droplet 100-300 micron w/fines

Less drift More drift

Heliport near application site Must ferry to air strip

Mobile heliport

Specially designed trucks:Load on top

DOT Spec 406 Certified Tanks

Section Tank

800 Gal. Jet Fuel

3000 Gal. Clean Water

1000 Gal. Chemical Mix

GPS Guidance System

•Trimble Trimflight 3 GPS System.

•Auto-Cal Flow Control

•Crophawk Flow Monitor

Trimble GPS Guidance

• Logs spray area for display on moving map

• Allows for flying irregular lines with less “skips”

• Produce computer generated application spray maps

Variable Rate Flow Meter

• Calibrate to ground speed

• Maintain constant 15 GPA / TSV flow

• Linked to GPS receiver

Spraying at 25-30 mph allows

turning without banking

Three section spray boom

15 – 30 – 45 ft. swath width controlled from cockpit

.028 Accuflo Nozzle1000 Micron Droplet15 g/acre TSV

Escort (metsulfuron methyl)• DuPont Sufonylurea Herbicide

– Inhibits acetolactate synthase (ALS)• Registered for general weed and brush control in

non-crop sites, conifer and hardwood plantations, rangeland, industrial turf (unimproved) and native grass restoration sites.

• Pre and Post activity on Grasses and Broadleaf Weeds– Root and Foliar uptake; moves in xylem and phloem

• Behavior in Water and Soil– At 25°C, half-life in water at 21 (pH 5) to 30 (pH 9)

days– Soil half-life ranged from 1-6 weeks and with an

average of 30 days.

Escort Aerial TrialsSalt Cedar

• 5 Locations: Big Spring & Midland, TX

• Application Date: Aug & Sept. 2003,2004, 2005

• Appl. Equipment: Helicopter• Appl. Volume: 15 Gal/Acre• Plot Size: 7.5- 10 acres• Pest Stage at Application:

– Mature, Post-Bloom, Pre-Senescent

Salt Cedar TrialsDuPont/TX A&M

2003-2005

0102030405060708090

100

11 YAT

Salt Cedar- % Canopy Reduction

Arsenal 16 (5)

Arsenal 8 + Escort 2.4 (1)

Arsenal 8 + Escort 1.8 (2)

Escort 2.4 (1)

Escort 1.8 + Krenite 192 (4)

Escort 1.8 + Remedy 48 (2)

Escort 1.8 + Krenite 192 +Arsenal 8 (2)

No. Tests ( )

Rate: oz ai/A

Salt Cedar TrialsDuPont/TX A&M

2003-2005

01020304050607080

11 YAT

% Control (Mortality)- 1 YAT

Arsenal 16 (5)

Arsenal 8 + Escort 2.4 (1)

Arsenal 8 + Escort 1.8 (2)

Escort 2.4 (1)

Escort 1.8 + Krenite 192 (4)

Escort 1.8 + Remedy 48 (2)

Escort 1.8 + Krenite 192 +Arsenal 8 (2)

No. Tests ( )

Rate: oz ai/A

Salt Cedar TrialsDuPont/TX A&M

2003-2005

0102030405060708090

12 YAT

% Control (Mortality)- 2 YAT

Arsenal 16 (3)

Arsenal 8 + Escort 2.4 (1)

Arsenal 8 + Escort 1.8 (0)

Escort 2.4 (1)

Escort 1.8 + Krenite 192 (2)

Escort 1.8 + Remedy 48 (2)

Escort 1.8 + Krenite 192 +Arsenal 8 (0)

No. Tests ( )

Rate: oz ai/A

Salt Cedar TrialsDuPont/TX A&M

2003-2005

0

10

20

30

40

50

60

1

41 DAT

% Injury- Alkali sacaton (Sporobolus airoides)

Arsenal 16 + Surf (1)

Arsenal 8 + Escort 2.4 +Surf (1)

Escort 2.4 + Surf (1)

Rate: oz ai/A

No. Tests ( )

Salt Cedar TrialsDuPont/TX A&M

2003-2005

0

5

10

15

20

25

30

1

41 DAT

% Injury- Saltgrass (Distichlis spicata)

Arsenal 16 + Surf (1)

Arsenal 8 + Escort 2.4 +Surf (1)

Escort 2.4 + Surf (1)

Rate: oz ai/A

No. Tests ( )

Salt Cedar TrialsDuPont/TX A&M

2003-2005

0

10

20

30

40

50

60

70

80

90

1

258 DAT

% Injury- Burrograss (Scleropogon brevifolius)

Arsenal 16 + Surf (1)

Arsenal 4 + Escort 1.8 +Surf (1)

Escort 1.8 + RU 16 + Surf(1)

Esvort 1.8 + Krenite 192 +Surf (1)

Escort 1.8 + Remedy 48ozai/A + Surf (1)

Rate: oz ai/A

No. Tests ( )

Summary of Trials

• Arsenal 16 ozai/A (imazapyr) gave good- excellent control of salt cedar

• Escort 1.8 + Arsenal 8 ozai/A and Escort 2.4 ozai/A gave good control of salt cedar and appeared safer to burrograss, alkali sacaton and inland saltgrass.

• Evaluate trials applied in 2006 and install new trials Sept. 2007 with Escort and DPX-KJM44.

Salt CedarReferences (web sites)

– www.invasivespecies.gov/teamtam/– www.invasivespecies.gov/profiles/

saltcedar.shtml– www.fs.fed.us/database/feis/plants/tree/

tamspp/all.html– www.tamariskcoalition.org– http://plants.usda.gov/– Cr-hart@tamu.edu (Dr. Charles Hart, TX

A&M)