ditomaso rrs jan 2012.ppt

1st Rangeland Research Symposium 1/19/2012

http://rangelandwatersheds.ucdavis.edu 1

Managing weeds to conserve diversity and

productivity

Joe DiTomaso

University of California, Davis

PreventionPrevention

Our first line of defenseOur first line of defense

Prevention BMPs Prevention BMPs Goal: To prevent accidental introduction

and spread of invasive plants

Two Prevention BMP Manuals:

1 for Land Managers1. for Land Managers

2. for Transportation and Utility Corridors

Prevention BMPsPrevention BMPsLand Manager Prevention BMPs

Manual Chapters: Pathways of Invasion

1. Planning & Inventory

2. Project Materials

3. Travel

4. Tool, Equipment & Vehicle Cleaning

5. Clothing, Gear & Boots Cleaning

6. Waste Disposal

Land Manager Prevention BMPs Land Manager Prevention BMPs

Available at:Available at:

www.calwww.cal--ipc.orgipc.org

Impacts on human activitiesLower livestock forage quality and quantityPhysically interfere with grazingCompromise livestock, horse or human healthIncrease cost of managing and producing livestock slow animal weight gainslow animal weight gain reducing the quality of meat, milk, wool, and hides

Impede recreation activitiesReducing land value



Impacts on biotic aspects of natural ecosystems

Reduce wildlife forage Alter wildlife habitatLower plant and animal diversity– natives or endangered species

Control options in rangelands Mechanical– Hand pulling, hoeing, weed whips– Tillage– Mowing

Cultural– Grazing– Prescribed burningPrescribed burning– Flaming

Biological – Pathogens– Insects

Chemical Integrated approaches– Combination of techniques– Revegetation + other technique

Consideration of primary long-term land-use objective

Forage production for livestock

Timber production

Preservation of native or endangered plantPreservation of native or endangered plant species

Wildlife habitat development

Water management

Recreational land maintenance

Mechanical Control Strategies

•Tillage or cultivation• Mowing

Mowing

Will select for - low growing annuals - perennials- species that have just

started their life cycle at the mowing timing

- species that have just completed their life cycle at the mowing timing

Tillage

Will select for ruderal annual species

When tillage is conducted too early it can select for other annuals that germinate over a long period



Cultural Control Strategies

•Grazing• Prescribed burning

Grazing

End of May grazing

Medusahead coverin summer

Re

lativ

e c

ove

r (%

)

5

10

15

20

25

30

35

Control of medusahead with grazing, Yolo County

0

Spring cover of other species

Time of grazing

Ungrazed Mar, Sep Mar, May, Sep May, Sep Sep

Re

lativ

e c

ove

r (%

)

0

20

40

60

80

100Broadleaf plantsGrasses other thanmedusa-head

Prescribed fire19971996

Bur

ned

0

20

40

60

80

100AVEfat

LOTwra

EROcic

TRIgra

NASpul

BRImin

AIRcar

BROhor

CENsol

BROdia

BROdia

CENsol

EROcic

AVEfat

NASpul

LACser

grass legume forb

p< 0.05

p< 0.1

VICsatCLApur

LATcic

SIDdip

TRImic

EPIfasCLApurLATx

TRIgra

VICvil

BROhor

LACser

LOTwra

BRIminTRImic

1998

Unburned

0 20 40 60 80 100

Bur

ned

0

20

40

60

80

100 1999

Unburned

0 20 40 60 80 100

BROdia

CENsol

TRImic

EROcic

LACser

NASpul

BROhor

NASpul

BROhor

CENsolBROdia

n.s.

native introduced

VULmyuPETnan

LATcic GERdis

AVEfat

LOTwra

TRIgra

BRImin

CLApur

LACser

AVEfatBRImin

Not foundon transect:CLApurEROcicLOTwraTRIgraTRImic

Kyser and DiTomaso. 2002. Weed Science 50, 648



Barb goatgrass control burn

% Vegetative cover or index value

Vegetation type Unburned burn

1997 1998 1999 1997 1998 1999

Pre-burnGrasses

barb goatgrass 45 62 63 55 54 0

native perennials 0 0 1 1 9 10

total grasses 127 156 152 116 173 68

DiTomaso et al. 2001. Cal. Ag. 55, 47.

Burning increased the native perennial grass Hordeum brachyantherum 13-fold while controlling barb goatgrass (Aegilops triuncialis)

Vegetative cover in July

60

70

80

Co

ver No burn

1 yr burn

3 yr burn

a a

0

10

20

30

40

50

Per

cen

t V

eget

ativ

e

Yellow starthistle Nassella pulchra

3 yr burn

b

b

a a

Burning for medusahead control in four counties

140

160

ol

After 1 yr burn After 2 yrs burn 1 yr after last treatment

0

20

40

60

80

100

120

% o

f untr

eat

ed c

ontr

o

Fresno Yolo Siskiyou Lassen

Biological Control

• Pathogens• Insects



Diorhabda elongata on Tamarix parviflora

Herbicide Application Methods

Broadcast

Directed Backpack sprayer or wick applicator– Backpack sprayer or wick applicator

– Woody plant control• Cut stump

• Stem injection (hack-n-squirt)

• Basal bark

Chemical

Broadcast applications

To achieve selectivity:-use selective herbicide-apply at specific timing

Transline (clopyralid) treated rangeland on right

Untreated Aminopyralid 3 oz/A



Effect of treatment timing on coast fiddleneck (Amsinckia menziesii) control in Davis, California

8090

100

2 oz/A 3 oz/A 4 oz/A 5 oz/A Transline 8 oz/A

Milestone

0

1020304050

6070

November December January

**

*

* LSD (P=0.05)

Effect of aminopyralid and clopyralid on grass forage in following year

500

600

m)

2 oz/A 4 oz/A 8 oz/A Transline Untreated

**

0

100

200

300

400

Fo

rag

e w

t (g

/sq

Rosette Bolting

Plant Stage when Treated

***

**

**

*LSD (P=0.05)**LSD (P=0.01)

Directed treatmentsDrizzle Application

Backpack sprayer

Wick applicatorStem applications

Cut stump

Basal barkStem injection (hack-n-squirt)



Yellow starthistle cover following two years of control

15

20

25

cove

rYuba County

a

b

0

5

10

Bu

rn/b

urn

Bu

rn/c

lop

yr

Con

trol

Clo

pyr

/bu

rn

Clo

pry

/clo

pyr

Per

cent

y

b bb

ab

a a

bb

cc

cc

c c

Thank you! Questions?

ditomaso rrs jan 2012.ppt

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