2011 Hanson_Tulare Olive Day2

8/7/2019 2011 Hanson_Tulare Olive Day2

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Brad HansonUC Davis Weed Science

Southern San JoaquinValley Olive Day4-19-11 Tulare, CA


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Complex populations

Rarely just one weed species present

Annual vs perennial vs biennial

Grass vs sedges vs broadleaf

Time of emergence

Fall vs spring emergence vs year-round

Reproductive strategy

Seed vs vegetative


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Factors affecting orchard weeds

Orchard age and arrangement

Shading and space capture

Irrigation type, timing, and amount

Furrow, sprinklers, micros, drip

Tillage practices

Berms, cross-disking, etc

Herbicide program and choices

Orchard access


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Integrated weed management

Using all available strategies to manageweed populations in a manner that iseconomically and environmentally

sound. cultural

mechanical

chemical


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Weed identification

Unknown weeds cannot be properlymanaged

No technique controls all weed species

Not all weeds cause equal damage (thresholds)

Species respond differently to control strategies

Even variants within a species (ie. herbicideresistant biotypes)

Weed Research and Info Centerhttp://wric.ucdavis.edu

Online weed ID tool


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Mechanical and cultural methods

Tillage

Best when weeds are small < 4 in.

Dry conditions after help to prevent re-rooting Shallow cultivation reduces the quantity of new

seeds brought to the surface

Cultural

Manage orchard operations to disfavor weeds

Irrigation, fertility, shading, etc


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2010 tree and vine crops herbicide

registration chart

UC Davis Weed Researchand Information Centerhttp://wric.ucdavis.edu/

Also, on UC Weed Scienceblog
http://wric.ucdavis.edu/


8/16

Herbicides registered in olive

Chateau*Gallery*Surflan

Prowl

Diuron.SimazineGoal, GT

Prism*Diquat*Fusilade*

Poast*

SharkGlyphosateGramoxone

Venue (dorm.)

* Registered for non-bearing olive only


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Herbicides NOT registered in olive

(but possible in future) Rely 280 glufosinate

Broad spectrum contact herbicide Labeled in many tree and vine crops

Alion indaziflam, new AI Broad spectrum residual activity Likely 2011 tree nut, pome, stone label

Pindar GT combination of penoxsulam and oxyfluorfen Contact and residual activity on grass and broadleaf Labeled in tree nuts

Treevix saflufenicil, new AI Contact broadleaf herbicide Registered in many nut and fruit crops, not in olive in near term


10/16

CA olive herbicide use

Top 10 active ingredients 2009 treated acreage

1 glyphosate 44,961

2 oxyfluorfen (Goal 2XL) 19,979

3 oryzalin (Surflan, etc) 6,014

4 simazine (Princep) 5,582

5 diuron (Karmex, Direx) 5,022

6 carfentrazone (Shark) 4,985

7 paraquat (Gramoxone) 2,173

8 flumioxazin (Chateau) 6709 sethoxydim (Poast) 480

2010: 33,000 A bearing*strip treated acreage vs orchard acreage


11/16

A word about selection pressure

Over reliance on one weed controltool can lead to selection for weedspecies or biotypes that avoid,

escape, or are resistant In 2009:

53% of all olive herbicide applic. were glyphosate

Currently 21 HRW species in CA 5 with glyphosate resistance

2 ryegrasses, horseweed, fleabane, barnyardgrass


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Resistance or shifts to tolerant species


13/16

World-wide resistance by MOA

0

20

40

60

80

100

120ALS inhib

PSII inhib

PPO inhib

byridilium

sythetic auxins

glycines

ACCase inhib


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Orchard weed management

Weed ID

Understand the problem and biology

Use integrated management tactics

Cultural and mechanical approaches

Chemical tactics

Right herbicide, right target, right time

Resistance management considerations Environmental effects

VOC, surface water, ground water


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UC Davis Weed Researchand Information Center

http://wric.ucdavis.edu/http://ucanr.org/blogs/UCDWeedScience/

Brad Hanson

UC Davis Statewide IntegratedPest Management Program

http://www.ipm.ucdavis.edu/

Wow that IS pretty simple!
http://wric.ucdavis.edu/http://wric.ucdavis.edu/


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Thank you
http://ucanr.org/repository/fileaccess.cfm?article=75077&p=CZMNWZ

Documents

2011 Hanson_Tulare Olive Day2