weedy rice update

Weedy Rice Update

UCCEWinterGrowerMeetings2018

WhitneyBrim-DeForest,RiceAdvisor

Survey: Winter 2017

• 160growersandPCA’sweresurveyedat5meetingsin4counties(Butte,Glenn,Colusa,andSutter):• 40%respondedthattheyhadsuspectedafieldwasinfestedwithweedyrice• 49%statedthattheyhadseenitpriorto2016• 57%hadnotreportedtheinfestationtoUCCE

• Approximately25%ofinfestationslikelynotreported

Bytheendoftheseason,wehadatotalof:• 53samplessubmittedfortesting• Outofthe53,22confirmedtobeweedyrice• About42%ofthesamples!

Eightseedfieldswerefoundtobeinfestedwithweedyriceandwererejectedasseedfields:• 3werenewmediumgrainseedfields• 1wasanestablishedmediumgrainseedfield• 4werespecialtyvarietyseedfields

FieldSurvey:2017

No new biotypes identified

Photos:TimothyBlank,CCIA

Sprangletop:-Likerice(andweedyrice),ithasaligule,soitcanbeconfusing(esp.beforeheading)-Hasawhitestripedownthemiddleoftheleaf(mid-vein)

ElongatedUpperInternode(EUI):-Ageneticabnormalityofcommonmediumgrainricevarieties-Causesthepartofthestemattachedtothericepanicletoelongate-Theplantwilllookjustlikethevarietyplantedinthefield

Research Updates

Soil Seedbank Surveys: Fall 2016

•  Sample10fieldswithknowninfestations•  34soilcorestakenevery20feetalongtransect•  Soilsampleswerewashedinasaline(salt)solutiontoextractorganicmatter• RiceseedsfoundineachcoreweresubjectedtoaKOH(potassiumhydroxide)test

Table 1. Weedy rice seed counts from soil samples collected in Fall 2016. County Ecotype Seeds m-2 Samples Present (%) Butte 1 31.3 41 Sutter 1 2.3 6 San Joaquin 1 23.2 32 Glenn 1 4.6 9 Yuba 2 29.0 21 Sutter 2 4.6 12 Colusa 3 2.3 6 Colusa 3 7.0 18 Sutter 5 39.5 42 Yolo Control 0.0 0

165,000seedsperacre

9500seedsperacre

Research Updates WeedyRiceBiotypeUpdates

•  Type1:•  Awnless•  Strawhullcolor•  Tallstature•  Nocoloronnodes

•  Allrice-growingcounties(exceptforColusa)

0

20

40

60

80

100

120

SHA

T

CARV Type_1 Type_2 Type_3 Type_4 Type_5

Ecotype

0.0125Prob > F3.30F

Distribution of SHAT

0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F

Distribution of SHATBreakingte

nsilestrength(gf)

18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F

Distribution of DORM

18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


%Germination

Type1:•  Highshattering•  Highdormancy

ImplicationsforManagement:•  Highdepositionintoseedbank•  Lengthoftimeinsoil:manyyears

•  Type2:•  Awnless•  Bronzehullcolor•  Tallstature•  Nocoloronnodes

•  Butte,SutterandYubaCounties

0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


nsilestrength(gf)

18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


%Germination

Type2:•  Highshattering•  Lowdormancy

ImplicationsforManagement:•  Highdepositionintoseedbank•  Lengthoftimeinsoil:short!

•  Type3:•  Awned•  Strawhullcolor•  Tallstature•  Nocoloronnodes

•  GlennandColusaCounties

0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


nsilestrength(gf)

18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


%Germination



•  Type4:•  Awned•  Blackhullcolor•  Shortstature•  Nocoloronnodes

•  Currentlyinonelocation,GlennCounty

0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


nsilestrength(gf)

18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


%Germination



•  Type5:•  Awnless•  Strawhullcolor•  Tallstature•  Purple-colorednodes

•  Sutter,Yuba,andYoloCounties

0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


0

20

40

60

80

100

120

SHA

T


Ecotype

0.0125Prob > F3.30F


nsilestrength(gf)

18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


18

19

17

37

0

20

40

60

80

100

DO

RM


Ecotype

<.0001Prob > F27.43F


%Germination

Type5(twogroups):•  Highshattering•  Lowdormancy

ImplicationsforManagement:•  Highdepositionintoseedbank•  Lengthoftimeinsoil:short!

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

RESVarieties

Koshihikari Type1 Type2 Type3 Type4 Type5

Chloroph

yllcon

tent(Spa

dun

it)

CAWeedyRice

Leafcolorintensity(chlorophyllcontent) CAweedyrice

Phenotypiccharacterizationsofweedyrice

RESricevarieties

S102M205

L202 3LFF

2.12.2

14

5

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

RESVarieties Koshihikari Type1 Type2 Type3 Type4 Type5

Plan

tHeight(cm

)

CAWeedyRice

Plantheightmeasurement

RR116RR111

RR133 M-205

144cm99cm74cm86cm

Characteristics Populations Durationoftimeinsoil

Highdormancy,highshattering Type1,Type3,Type4 Long-term(maybe10

ormoreyears)

Lowdormancy,highshattering Type2,Type5

Shorter(likelytobeafewyears,butonlyifmoreseedisnotbeingputintothesoilseedbank)

•  Allpopulationsare:red-branned(redpericarp)•  Allpopulationsare:lightergreenthanJaponicavarieties•  Allpopulationsare:tallerthanCalrosevarieties

Summary of Preliminary Genetics

•  Fivegeneticgroups,whichalignwellwithoutwardcharacteristics(phenotypes)

•  Type1:Mostcloselyrelatedtoblack-hulledweedyricefromthesouthernUSandAusvarieties

•  Type2:Mostcloselyrelatedtostraw-hulledweedyricefromthesouthernUSandIndicavarieties



•  Type5:MostcloselyrelatedtoJaponica(bothtemperateandtropicalvarieties)Types3and4aremostcloselyrelatedtoeachother!

Types2,3and4closelyrelatedtoeachother!

DiverseCaliforniaweedyredriceecotypesàmultiplepossibleorigins!!!

Type1Type2Type3Type4Type5 M-205

Herbicide Screening

Pre-emergentHerbicideTesting

Control Abolish Goal Prowl

Treatments and Rates

• Herbicideswereapplied1dayafterplantingtheseedstoabout1cmdepth(simulatedrill-seededsystem)• Picturesweretaken23daysafterspraying

• Herbicides:• Prowl-2pts/A• Abolish-2qts/A• Goal2X-2pts/A

Control Abolish Goal Prowl

Noeffectonanyoftheweedyricebiotypes

Bolero GraniteGR Cerano Butte

Post-emergentGranularHerbicideTesting

Treatments and Rates

• Herbicideswereapplied10daysafterplanting(1-2leafstageofrice)•  Twodaysafter(48hrs)plantswereplacedat4-inchwaterdepth• Picturesweretakentwoweeksafterherbicideapplication

• Herbicides:• Bolero-23.3lbs/A• Cerano-12lbs/A• Butte-7.5lbs/A• GraniteGR–15lbs/A

Bolero Butte Cerano GraniteGR

Control

M-205

LeafbleachingofM-205byCerano.

Weedyricetype1


ControlsM-205 WR-T1 WR-T1 WR-T1 WR-T1 WR-T4

StuntingofWRtype1byabout50%byBolero.



Weedyricetype2

StuntingofWRtype2byabout50%byBolero.

Weedyricetype3



BoleromakesWRtype3stuntedbyabout35%.LeafbleachingbyCerano.

Weedyricetype4



WRtype4leavesarebleachingbyCerano.

Weedyricetype5



NoeffectonT5.

Granular Herbicide Screening Summary

•  SomeinjurynotedonTypes1-4fromBolero,butplantsrecovered•  Type5:noinjuryfromanyherbicides

ClethodimSpot-SprayingintheFieldCollaborator:JimCook

•  Spot-sprayedtilleringType3weedyrice

•  Treatment1:3seconddurationsprayof2/3%V/VSelectMax+0.25%V/VNIS

•  Treatment2:5seconddurationsprayof2/3%V/VSelectMax+0.25%V/VNIS

•  Treatment3:3seconddurationsprayof2/3%V/VSelectMax+1%V/VCOC

•  Treatment4:5seconddurationsprayof2/3%V/VSelectMax+1%V/VCOC

•  Damagetosurroundingriceextendednomorethan9.6inches(foralltreatments)

•  LongerdurationprovidedbettercontrolwhenusingNIS(5seconds)

•  TreatmentswithCOCassurfactantprovidedbettercontrol,regardlessofduration(82%and93%)

0

10

20

30

40

50

60

70

80

90

100

Trt1 Trt2 Trt3 Trt4%Con

trol

8DAT 18DAT 25DAT

weedy rice update

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