Ecology & Management of

Ventenata in the Inland Northwest

John Wallace, Tim Prather, Andrew Mackey & Pamela Pavek

University of Idaho & USDA-NRCS Plant Materials Center

WSARE Project (2011-2013)

jwallace@uidaho.edu

Outline

WSARE Project

Measuring Impacts: Production & Conservation

Ventenata Biology

Ventenata IPM Development

VEDU Identification

Annual Grass Invasion Ventenata (African wiregrass) distribution in Inland

Northwest

Source: P. Pavek, USDA-NRCS-PMC

Ventenata Weediness in Inland Northwest UI-SSRU; 2011 Survey

Ventenata weediness?

% of Respondents

0 20 40 60 80 100

non-crop

pasture

grass-hay

CRP

timothy-hay

bluegrass

wheat

Source: Kane, UI-SSRU

VEDU Impacts on Management 2011 Producer Mail Survey (UI-Social Science Research Unit; S. Kane)

Ventenata Impact

Time Period

1970-1980 1981-1990 1991-2000 2001-2010

No

. o

f P

rod

ucer

Resp

on

den

ts

0

20

40

60

80

100

120

140

160Year EstablishedBegan Control

VEDU Impacts

Relative Level of Impact

No A Little Bit A Great Deal

% o

f P

rod

ucer

Resp

on

den

ts

0

10

20

30

40

50

60

70

Increased CostAltered Management

Source: Kane Source: Kane

VEDU Impacts on Enterprise Budgets 2011 Delphi Surveys (UI Ag Econ; K. Painter)

Example:

Timothy Hay Management Scenario

Stand

Life

Price

($/tn)

Yield

(tn/ac)

Net

Revenue

Can’t sell hay 5 0 2.4 -236

Sell hay at reduced yield & price 5 70 2.4 -77

VEDU managed (price & yield reduced) 10 120 2.7 26

No VEDU present 10 200 3 201

Enterprise Budgets: 1) timothy hay, 2) grass hay, 3) small pasture, 4) CRP

Survey Standard Control Strategies Cost-Price-Yield Revenue

VEDU Impacts on Wildlife Habitat 2012-2013 (UI: A. Mackey)

% Cover by

Functional

Group

No. Individuals at

Reproductive

Stages

Ventenata Ecology in Perennial

Grass Systems

Growth & Development Patterns

Degree Day Model (DDM) Development

Seedbank Life & Germination Response to Temperature

VEDU Litter Effects on VEDU populations

VEDU x Endophyte Interactions

Regional VEDU Growth Models in PNW 2011-2013 (UI Weed Sci, OSU: Sbatella)

Site Location System Moscow ID CRP Worley ID CRP Harvard ID Timothy Hay Usk WA Timothy Hay Helmer ID Pasture Usk WA Pasture Anatone WA Range Enterprise OR Range Madras OR Range (12-13)

Regional VEDU Growth Models in PNW 2011-2013 (UI Weed Sci, OSU: G. Sbatella)

Expected Outputs:

1) Hydro-thermal models (GDD approach) for VEDU phenological growth stages:

seedling emergence (cumulative)

vegetative stem elongation inflourescence seed ripening

2) Comparative vegetative growth models with annual and perennial grasses:

bluebunch wheatgrass, intermediate wheatgrass, orchardgrass, smooth

brome, timothy, downy brome, medusahead

Early Observations:

• Seedling emergence strongly affected by available soil moisture

• Greater spring seedling emergence in higher managed systems (timothy hay)

• Later mean seedling emergence in rangeland systems? Soil moisture effect?

VEDU Seed Biology 2009-2012 (NRCS: P. Pavek, UI Weed Sci)

Seedbank Life:

• 2 sites in Palouse Prairie

• 2 depths (2 & 8 cm)

• Seeds per packet: 100

• Initiated: 1 Oct 2009

Temperature Effects on Germination:

• 5 populations across region

• Expected Outputs:

optimal germination temperature

days to mean germination

germination thresholds

between population variation

Months after Burial

Site 1 6 12 24 36

------- % germination -------

Pullman WA

2 cm 81 0 <1 0 <1

8 cm 80 0 0 0 0

Moscow ID

2 cm 83 0 0 <1 0

8 cm 80 0 0 0 0

Temperature (C)0 5 10 15 20 25 30

% T

otal

Ger

min

atio

n

0

20

40

60

80

100

Litter Effects on VEDU Growth & Development 2011-2013 (UI Weed Sci)

Litter Effects on VEDU Growth & Development 2011-2013 (UI Weed Sci)

VEDU Seedling Density

2011-2012

Oct Nov Dec Jan

VE

DU

See

dli

ng D

ensi

ty (

per

pot)

0

20

40

60

80

100

No Litter

5-g Litter

10-g Litter

20-g Litter

Increased VEDU litter (%) 1. Higher germination rates 2. Higher seedling survival 3. Higher seedling growth rates

VEDU Litter Effects

2011-2012 Growing Season

Oct Nov Dec Jan S

oil

Volu

me

Wat

er C

onte

nt

0.00

0.05

0.10

0.15

0.20

0.25No Litter

5-g Litter

10-g Litter

20-g Litter

Increased VEDU litter (%)

1. Higher soil moisture 2. Lower max temperatures 3. Higher min temperatures

Endophyte Effects on Grass Competitors? 2012-present (UI: G. Newcombe & D. Griffith)

Control BRTE

Fusarium

VEDU

Fusarium

Fusarium Effects

on Downy Brome

Above

ground B

iom

ass

(g)

Above

ground B

iom

ass

(g)

Fusarium Effects

on Ventenata

Control BRTE

Fusarium

VEDU

Fusarium

VEDU˟Endophyte Effects on Community

Assembly? 2012-present (UI: G. Newcombe & D. Griffith)

Control BRTE

Fusarium

VEDU

Fusarium

Above

ground B

iom

ass

(g)

Fusarium Effects on

Bluebunch Wheatgrass

Ventenata Management:

Control & IPM

2011-2012 Field Trials (Pre- and Post-Emergent Apps)

2012-present IPM Trials (CRP, hay, pasture)

Ventenata Control in Perennial Grass Systems 2011-present (UI Weed Sci)

Site Location Perennial Grass Stand

Soil

Texture

% Organic

Matter Soil pH

Anatone WA Bluebunch wheatgrass silt loam 6.5 6.2

Grangeville ID Timothy loam 7.4 5.4

Moscow ID Smooth brome/Orchardgrass silt loam n/a n/a

Moscow ID Intermediate wheatgrass silt loam 4.1 5.7

Grangeville ID Intermediate wheatgrass clay loam 3.7 5.6

Applications (Fall 2011):

• 5 selective herbicides per site; 2 application timings (pre- and post-emergent)

• Pre-emergent (Oct 7-10) & Post-emergent (Nov 1-10; 1-2 leaf stage)

Label Summary

Product (chemical)

fl oz/ac

($/ac)

VEDU

Labeled

Labeled for

Use

Other Weedy

Grasses

Controlled

Grazing Restrictions

Outrider;

(sulfosulfuron)

1.0

($17/ac)

No non-crop

pasture

rangeland

CRP

natural areas

downy brome

bulbous bluegrass

No grazing restriction;

Rest 2 wks before and

after application for

best results.

Plateau

(imazapic)

6.0

($10/ac)

No aerial application

forage grass

grass/legume forage

CRP Land

small pasture

rangeland

downy brome

medusahead

meadow foxtail

Italian ryegrass

No grazing restriction;

Do not harvest hay for

7 d after treatment

Matrix

(rimsulfuron)

3.0

($40/ac)

No aerial application

non-ag wildlife

non-crop agriculture

federal EDRR

downy brome

Italian ryegrass

meadow foxtail

medusahead

No established

tolerance for forage

grass or grazing; 1 yr

grazing restriction

Canter

(propoxy-

carbazone)

1.0

($14/ac)

No CRP land

pasture

rangeland

grass-hay

downy brome

rattail fescue

windgrass

No grazing restriction

Axiom

(flufenacet/

metribuzin)

8.0

(n/a)

No none applicable

grass-hay?

downy brome

meadow foxtail

rattail fescue

--

VEDU Control1 Perennial Grass Injury (PRE/POST)2

Treatment (prod/ac) PRE/POST PSSP THIN DAGL BRIN PHPR

-- % -- ----------------------- % ----------------------

Outrider (1 oz/ac) 88/96 na/5 0/9 13/11 9/11 na/16

Plateau (6 oz/ac) 73/86 na/0 0/0 13/10 13/10 na/55

Matrix (3 oz/ac) 97/95 na/3 13/4 0/0 0/0 na/20

Canter (1 oz/ac) 66/80 na/0 0/0 8/1 8/1 na/4

Axiom (8 oz/ac) 90/83 na/0 0/0 0/0 0/0 na/0

Ventenata Control in Perennial Grass Systems 2011-present (UI Weed Sci)

1 VEDU control averaged across sites 2 PSSP = bluebunch wheatgrass; THIN = intermediate wheatgrass; DAGL =

orchardgrass; BRIN = smooth brome; PHPR = timothy

* Ratings based on peak biomass evaluation (10 Jul 12); no treatment effect

on yield in comparison to untreated check

IPM Decision Tool Development 2012-Present (UI Weed Sci)

IPM Strategies NPK Fertilization Timing & Crop Competitiveness

Timothy Hay Management Guidelines:

(S. Fransen; WSU-IAREC, Prosser WA)

• Higher harvest heights (> 5 in) preserve stored sugars important for surviving drought stress and growth • Fall P&K fertilization increase root and shoot development, resulting in earlier spring green-up.

IPM Fertilizer Treatments: • NPK rates based on fall soil sample + recommendations (UI Forage) • PK fall application timed to precede fall rains • N spring application timed to GDD recommendations (UI Forage)

VEDU IPM for Timothy Hay 2012-present (UI Weed Sci)

Timothy Hay

Treatment Layout

Cultural Treatment (Harvesting Height)

5” height 2” height

2” height

+ fall graze Control

VEDU

Control

Treatment

Fall Spray

Axiom

8 oz/ac

5” height

+ Fall Spray

2” height

+ Fall Spray

2” hgt + graze

+ Fall Spray

Fall Spray

+ Control

No Spray

5” height

+ No Spray

2” height

+ No Spray

2” hgt + graze

+ No Spray

Control

+ Control

Study Design • Replicated at LOW (<20% cover) & HIGH (>40% cover) sites • Replicated at two study areas

5” harvest height (M) vs. 2” + graze (L) & 2” (R)

Sept 2012

VEDU IPM for CRP Systems 2012-present (UI Weed Sci)

CRP

Treatment Layout

Cultural Treatment (Litter Removal & Crop Stimulation)

Spring

Burn Fall Burn

Fall

Fertilize Mow

Mow and

Remove Control

VEDU

Control

Treatment

Fall Spray

Outrider

1 oz/ac

Spring

Burn + Fall

Spray

Fall Burn +

Fall Spray

Fertilize +

Fall Spray

Mow +

Fall Spray

Mow and

Remove +

Fall Spray

Fall Spray

+ Control

No Spray

Spring

Burn + No

Spray

Fall Burn +

No Spray

Fertilize +

No Spray

Mow +

No Spray

Mow and

Remove +

No Spray

Control +

Control

Study Design • Replicated at LOW (<20% cover) & HIGH (>40% cover) sites • Replicated at two study areas

Fall Burn + Spray vs. Mow + Remove

Fall Burn + Spray vs. Control (5 MAT)

Spring Burn in HIGH VEDU Plots

Spring Burn in LOW VEDU Plots

VEDU IPM for Small Pasture Systems 2012-present (UI Weed Sci)

Pasture

Treatment Layout

Cultural Treatment (Grazing Timing)

Summer

Graze Fall Graze Fertilize Control

VEDU

Control

Treatment

Fall Spray

Outrider

1 oz/ac

Summer

Graze

+ Fall Spray

Fall Graze

+ Fall Spray

Fertilize

+ Fall Spray

Fall Spray

+ Control

No Spray

Summer

Graze +

No Spray

Fall Graze

+ No Spray

Fertilize

+ No Spray

Control

+ Control

Study Design • Replicated at LOW (<20% cover) & HIGH (>40% cover) sites • Replicated at two study areas

QUESTIONS

John Wallace, Tim Prather, Andrew Mackey & Pamela Pavek

University of Idaho & USDA-NRCS Plant Materials Center

jwallace@uidaho.edu

Ventenata Resources: • NRCS Bulletin: www.plant-materials.nrcs.usda.gov/pubs/

• PNW Weed Mmgnt Handbook: www.pnwhandbooks.org/weed/

• Ventenata Email Listserve: jwallace@uidaho.edu

QUESTIONS

VEDU Impacts on Regional Economy 2012 Input-Output Model (UI Ag Econ; P. Watson)

Scenario: No VEDU management in hay &

forage

Impact

Type* Jobs

Regional GDP

($ millions)

Direct -151 -89

Indirect -205 -27

Induced -208 -22

Total -564 -139

* Impacts include indirect & induced effects. Induced effects measure ‘multiplier’

effects at a regional economy scale

Scenario: VEDU managed in hay & forage at

a reduced loss in net revenues

Impact

Type* Jobs

Regional GDP

($ millions)

Direct 124 -15

Indirect -45 -5

Induced -10 -0.74

Total 69 -22

Work Truck (X1090)

October 25, 2011

CRP – Agricultural Matrix

Moscow ID

Palouse Prairie Remnant

Moscow ID

Pasture - CRP

St Maries ID

Highway 95 Roadcut

Northern Idaho

Pretreatment Soil Samples

System Site Ventenata Infestation

Available P µg/g

Available K µg/g

NH4-N µg/g

% Organic Matter pH

Pasture

Olesen Low 7.2 270 1.5 3.0 5.6

High 3.8 130 1.8 2.2 5.6

Park Ranch

Low 3.7 210 2.8 4.5 5.8

High 1.8 100 2.0 3.3 5.6

CRP

Jackman Low 1.9 110 2.3 2.3 5.5

High 2.1 100 2.7 2.1 5.5

Carlson Low 2.9 110 1.9 2.0 5.7

High 2.7 120 1.5 1.8 5.7

Timothy

Driver North

Low 3.9 49 2.2 4.2 5.1

High 2.8 47 2.9 4.1 5.1

Driver South

Low 1.6 39 2.9 4.2 5.2

High 1.2 39 2.0 3.9 5.4