PaladinPaladin®® (DMDS), Midas(DMDS), Midas®® ((MeIMeI), and ), and PicPic-- ClorClor 6060®® (Chloropicrin): Drip(Chloropicrin): Drip-- and and

ShankShank--applied under Retentive Film for applied under Retentive Film for Strawberry Production in CaliforniaStrawberry Production in California

USDAUSDA--Pacific AreaPacific Area--Wide Methyl Bromide Alternatives ProgramWide Methyl Bromide Alternatives Program

Mona OthmanMona Othman¹¹, Jonathan Hunzie, Jonathan Hunzie¹¹, Steve , Steve KoikeKoike¹¹, Tom Gordon, Tom Gordon²², Romeo Serhijos, Romeo Serhijos¹¹, ,

and and HuseinHusein AjwaAjwa¹¹¹¹ University of California Davis, SalinasUniversity of California Davis, Salinas

²² University of California Davis, DavisUniversity of California Davis, Davis

USDAUSDA--Pacific AreaPacific Area--Wide Methyl Bromide Alternatives ProgramWide Methyl Bromide Alternatives Program

AKNOWLEDGEMENTSAKNOWLEDGEMENTSThis project was funded by the USDAThis project was funded by the USDA--ARS AreaARS Area--Wide Pest Wide Pest Management Program for Methyl Bromide Alternatives. Management Program for Methyl Bromide Alternatives. Additional support was provided by the California Additional support was provided by the California Strawberry Commission, United Phosphorus, Inc.Strawberry Commission, United Phosphorus, Inc., and and TriCalTriCal..

Chemical FactsChemical Facts

Literatures show that Literatures show that ““methyl iodide is three methyl iodide is three times less reactive than methyl bromide.times less reactive than methyl bromide.””

(Sims, 2011)(Sims, 2011)Bromine versus iodine: solubility of 3.41g/100g water versus Bromine versus iodine: solubility of 3.41g/100g water versus 0.03g/100g water. 0.03g/100g water.

Natural production of Natural production of organohalogensorganohalogens in the ocean: in the ocean: studies reported that marine studies reported that marine microalgamicroalga and seaweeds and seaweeds produce atmospheric methyl iodide. produce atmospheric methyl iodide.

(Gribble, 2003; Moore, 2008)(Gribble, 2003; Moore, 2008)

Application Facts Application Facts Many states have used Many states have used MeIMeI, about 15,500 acres , about 15,500 acres were treated in the Southeast, followed the EPA were treated in the Southeast, followed the EPA guidelines. California follows more stringent guidelines. California follows more stringent regulations by the DPR.regulations by the DPR.Strawberries are planted after methyl iodide has Strawberries are planted after methyl iodide has dissipateddissipatedEffective at about 40% lowers rates than Effective at about 40% lowers rates than MeBrMeBr..Applied only under retentive tarps (VIF,TIF)Applied only under retentive tarps (VIF,TIF)Protective measures during and after application Protective measures during and after application (i.e.; stewardship and training, re(i.e.; stewardship and training, re--entry, tarp entry, tarp cutting)cutting)

Strawberry Production in CaliforniaStrawberry Production in California

California as the leading state with strawberry valued at $1.2, 80% of the US production (USDA, ERS)Salinas/Watsonville reported the highest acreage increase: 401 acre (CSC acreage Survey, 2011)As a result As a result --

Strawberry Strawberry

applications alone accounted for applications alone accounted for more than 40 percent of Monterey more than 40 percent of Monterey CountyCounty’’s agricultural pesticide s agricultural pesticide use. use. (Monterey County Crop Report,2010)

Salinas

Yellow and Light Yellow Solutions?Yellow and Light Yellow Solutions?

CC22SS22HH66

Odorous (garlicOdorous (garlic–– like?)like?)

Color: yellow Color: yellow

Example of source of DMDS in Example of source of DMDS in environment: cabbage, environment: cabbage, broccoli, and aquatic plants broccoli, and aquatic plants

Registered as food additive in Registered as food additive in the US and Europethe US and Europe

CH3ICH3I

Odor: EtherOdor: Ether--likelike

Color: clear to light yellowColor: clear to light yellow

Source in nature: ocean Source in nature: ocean surface.surface.

Total and Marketable Yield Total and Marketable Yield Relative to MB/Relative to MB/PicPic in Salinas 2010in Salinas 2010Yield (g/plant) Treatment Relative to

MB/Pic (%) Minimum Maximum

Marketable Yield Per Plant

control 68.39 372 482Pic 94.01 474 690DMDS-Pic 350-100 102.43 579 714Pic fb DMDS 100 fb 350 95.06 557 655Pic fb metam-K 30 93.54 504 660Pic fb DMDS 100 fb 440 94.28 532 645MB/Pic 100 565 684

P=.002Total Yield Per Plant control 73.16 526 638

Pic 96.43 653 854DMDS-Pic 350-100 100.25 731 852Pic fb DMDS 100 fb 350 98.34 770 808Pic fb metam-K 300 95.56 697 828Pic fb DMDS 100 fb 440 93.49 672 784

P=.001

ObjectiveObjective

The objective of this study was to evaluate the The objective of this study was to evaluate the efficacy of DMDS AND efficacy of DMDS AND MeIMeI rates and doses for rates and doses for yield, soilyield, soil--borne pathogens, and weed control in borne pathogens, and weed control in strawberry production system strawberry production system

The focus of this presentation is to evaluate the overall yield,The focus of this presentation is to evaluate the overall yield, pathogens, and weeds during the growing season of 2010pathogens, and weeds during the growing season of 2010-- 2011 using different rates of chloropicrin, DMDS, and 2011 using different rates of chloropicrin, DMDS, and MeIMeI under Virtually Impermeable Films (VIF) and Polyethylene under Virtually Impermeable Films (VIF) and Polyethylene (PE) for MB/(PE) for MB/PicPic. .

Drip research area each bed is 100 feet long, each

treatment 4 beds

Shank research area each treatment is 3 passes, each

pass 300 feet

Salina’s Research Site

Sand 67%, silt 19.25%, clay13.75%, organic matter 1.2%. MoistureSand 67%, silt 19.25%, clay13.75%, organic matter 1.2%. Moisture 10.4%. 10.4%. pH 7.12, CEC 15 meq/100gpH 7.12, CEC 15 meq/100g

Materials and MethodsMaterials and Methods

Experiments were initiated on November Experiments were initiated on November 2, 2010 in Salinas, CA. Sequential 2, 2010 in Salinas, CA. Sequential application of application of metammetam was 5 days was 5 days following the primary application.following the primary application.

DripDrip--applied Treatmentsapplied TreatmentsTreatmentTreatment lbs/acrelbs/acre

Midas 98/2 Midas 98/2 IodomethanIodomethan/Chloropicrin/Chloropicrin 7575

Midas 33/67 Midas 33/67 IodomethanIodomethan/Chloropicrin/Chloropicrin 113, 169, and 225113, 169, and 225

Paladin 98 DMDSPaladin 98 DMDS 51 gal/acre51 gal/acre

Paladin 79/21 DMDS/ChloropicrinPaladin 79/21 DMDS/Chloropicrin 40, 50, and 60 gal/acre40, 50, and 60 gal/acre

PicPic 60 60 (96% (96% PicPic) ) 1,31,3--Dichloropropene/ChloropicrinDichloropropene/Chloropicrin

200, 300200, 300

SectagonSectagon 42 (42 (MetamMetam Sodium 42%)Sodium 42%) 35 gal/acre35 gal/acre

All treatments applied under VIF except MB/All treatments applied under VIF except MB/PicPic applied under STD PEapplied under STD PE

VIF/STD PEVIF/STD PE

MeBr/PicMeBr/Pic 350350

ShankShank--applied Treatmentsapplied Treatments

TreatmentTreatment lbs/acrelbs/acre

Midas 98/2 Midas 98/2 IodomethanIodomethan/Chloropicrin/Chloropicrin 90, 12090, 120

Midas 33/67 Midas 33/67 IodomethanIodomethan/Chloropicrin /Chloropicrin 113, 169, 225113, 169, 225

PicPic 60 60 (96% (96% PicPic) ) 1,31,3--Dichloropropene/ChloropicrinDichloropropene/Chloropicrin

250, 350250, 350

All treatments applied under VIF except MB/All treatments applied under VIF except MB/PicPic applied under STD PEapplied under STD PE

VIF/STD PEVIF/STD PE

MeBr/PicMeBr/Pic 350350

MethodsMethods

Tow standard 5 mil drip Tow standard 5 mil drip tapes were inserted in tapes were inserted in the beds and connected the beds and connected to headersto headers

Beds were Beds were tarpedtarped with with VIF for all treatments and VIF for all treatments and with standard with standard polyethylene tarp (STD polyethylene tarp (STD PE) for methyl bromide PE) for methyl bromide and high rates of and high rates of PicPic. .

MethodsMethods

InoculaInocula of of FusariumFusarium were buried into the were buried into the preformed beds 6 preformed beds 6 inches deep in the inches deep in the research site in Salinas research site in Salinas before fumigation. before fumigation.

Inoculated sand Inoculated sand pouches retrieved after pouches retrieved after fumigation, prepared fumigation, prepared for assay.for assay.

Treatments injected the tapes and flow rates, Treatments injected the tapes and flow rates, water pressure, and weight are monitored water pressure, and weight are monitored every 10 minutes every 10 minutes

Shank applicationShank application

Methods..continueMethods..continue

Strawberry plants (Albion Strawberry plants (Albion variety) were transplanted four variety) were transplanted four weeks after the applications.weeks after the applications.

Weed evaluations were made Weed evaluations were made prior to weeding activity prior to weeding activity throughout the growing throughout the growing season.season.

MethodsMethods

Plant harvest weekly. Plant harvest weekly.

Yield data were taken Yield data were taken weekly throughout weekly throughout the production season the production season and were graded as and were graded as marketable and marketable and nonmarketable yield.nonmarketable yield.

Plant vigorPlant vigor no significant differenceno significant difference

Total and Marketable Yields: Drip ApplicationSalinas 2010-2011

200

400

600

800

1000

1200

unt (VIF) Paladin40 (VIF)

Paladin50 (VIF)

Paladinpure 51

(VIF)

Paladin60 (VIF)

Midas 75 (VIF)

MidasGold

33/67 113 (VIF)

MidasGold

33/67 169 (VIF)

MidasGold

33/67 225 (VIF)

PIC60 200 (VIF)

PIC60 200 fbmetam (VIF)

Pic60 300 (Std)

PIC60 300 FBmetam(Std)

MB 350

Treatments

Yiel

ds (g

/pla

nt)

Marketable Yield

Total Tield

Yields from all treatments except Midas 75 lbs/acre were significantly higher than yield from control Yields from all treatments are significantly higher than yield from Midas at 75 lbs/acre.(*) The only treatment was significantly lower than MBr/Pic was Midas at 75 lbs

**

Marketable yield (g/plant) Total yield (g/plant)

Treatmentslbs/acre

Relative to

MBr/Pic

% Minimum Maximum

Relative to

MBr/Pic

% Minimum Maximum

Untreated (VIF) 73 491 614 76 671 807Paladin 40 (VIF) 96 702 781 96 885 997Paladin 50 (VIF) 92 601 865 94 818 1091Paladin pure 51 (VIF) 97 676 789 97 886 992Paladin 60 (VIF) 95 674 814 96 870 1044Midas 75 (VIF) 76 540 604 80 753 809Midas Gold 33/67 113 (VIF) 100 671 841 98 858 1039Midas Gold 33/67 169 (VIF) 96 716 778 96 933 964Midas Gold 33/67 225 (VIF) 96 652 809 96 875 1006PIC60 200 (VIF) 90 580 771 92 796 988PIC60 200 fb

metam

(VIF) 103 732 855 103 954 1079Pic60 300 (Std) 97 657 849 97 880 1074PIC60 300 fb

metam

(Std) 98 697 837 99 902 1105P value = .001 P value = .001

Yield from Drip Applied Treatments in Salinas-September 2011

Marketable and Total Yields-Shank Application Salinas 2010-2011

100

200

300

400

500

600

700

800

900

1000

Control Midas 98/2 90lbs VIF

Midas 98/2 120 VIF

Midas 33/67 150 VIF

Midas 33/67 200 VIF

Midas 33/67 250 VIF

PIC60 250 TIF Pic60 350 std MB/PIC 350std

Treatments

Yiel

ds (g

/pla

nt)

Marketable YieldTotal Yield

** *

(*)Yields are significantly lower than MBr/Pic

Yields from all treatments except Midas 90 and 120 lbs/A are significantly higher than control. Yields from Midas rates of 150, 200, 250 lbs are not significantly different. Yields from Midas 98/2 at 90 lbs and 120 lbs yields were significantly lower than yield from MBr/Pic, Pic 250 and 350

Treatmentslbs/acre

Marketable Yield (g/plant) Total Yield (g/plant)

Relative to

MBr/Pic

(%)

Minimum Maximum

Relative to

MBr/Pic

(%)

Minimum Maximum

Control 65.47 306 511 68.64 456 719

Midas 98/2 90 VIF 76.71 397 468 78.98 600 675

Midas 98/2 120 VIF 75.38 381 483 78.37 541 703

Midas 33/67 150 VIF 83.24 396 511 85.11 573 730

Midas 33/67 200 VIF 83.91 390 548 85.11 582 738

Midas 33/67 250 VIF 89.73 403 618 90.49 567 864

PIC60 250 TIF 97.64 484 642 98.57 713 878

Pic60 350 std 102.53 467 651 103.37 684 891

P value=.008 P value=.005

Yield from Shank Applied Treatments in Salinas-September 2011

Selected Weeds in SalinasSelected Weeds in Salinas

Annual bluegrass. Poa annua. Lambsquarter. Chenopodium album. Bindweed. Convolvulus arvensis. Pigweeds Amaranthus spp.

(*) Means are significantly higher than MB/(*) Means are significantly higher than MB/PicPic std at the .05 levelstd at the .05 level Best treatment: Midas Gold 225 VIF suppressed weed by 88%. It waBest treatment: Midas Gold 225 VIF suppressed weed by 88%. It was better than MB/s better than MB/PicPic. Followed by Pic60 300 . Followed by Pic60 300 fbfb metammetam Std and Midas at 169 lbs (87% and 85%). Std and Midas at 169 lbs (87% and 85%). Although not significantly different, weed density was lower undAlthough not significantly different, weed density was lower under Pic60 200 and 300 er Pic60 200 and 300 fbfb metammetam than under Pic60 alone. than under Pic60 alone. All Midas treatments provided weed control equivalent to All Midas treatments provided weed control equivalent to MeBr/PicMeBr/Pic Pure Paladin suppressed weed by 82%.Pure Paladin suppressed weed by 82%.

Season-long Weed Density Per Acre in Salinas 2010-2011

102030405060708090

Control Midas75 (VIF)

MidasGold

33/67 113(VIF)

MidasGold

33/67 169(VIF)

MidasGold

33/67 225(VIF)

Paladin40 (VIF)

Paladin50 (VIF)

Paladinpure 51

(VIF)

Paladin60 (VIF)

PIC60 200(VIF)

PIC60 200 fbmetam(VIF)

Pic60 300(Std)

PIC60 300 FBmetam(Std)

MB 350(Std)

Drip-applied Treatments

Wee

d D

ensi

ty (c

t/acr

e)/1

000

*

* *

(*) Means are significantly higher than (*) Means are significantly higher than MeBrMeBr at the .05 level.at the .05 level. Weed count from every treatment was significantly lower then untWeed count from every treatment was significantly lower then untreated.reated. Weed count from Midas 33/67 at 150 lbs was significantly higher Weed count from Midas 33/67 at 150 lbs was significantly higher than weed count from than weed count from MeBrMeBr Weed count from Weed count from PicPic 250 lbs was significantly higher than 250 lbs was significantly higher than MeBrMeBr

Season-long Weed Density per Acre in Salinas 2010-2011

102030405060708090

Untreated Midas 98/290 (VIF)

Midas 98/2120 (VIF)

Midas33/67 150

(VIF)

Midas33/67 200

(VIF)

Midas33/67 250

(VIF)

PIC60 250(VIF)

Pic60 350(VIF)

MeBr 350

Shank-applied Treatments

Wee

d Nu

mbe

rs (c

t/acr

e)/1

000

P<.0001*

**

FusariumFusarium oxysporumoxysporum

Photos courtesy of Christina Islas

Fusarium Oxysporum Density 2010

0

1000

2000

3000

4000

5000

6000

7000

8000

Control Midas 75(VIF)

Midas Gold33/67 113

(VIF)

Midas Gold33/67 169

(VIF)

Midas Gold33/67 225

(VIF)

PIC60 200(VIF)

PIC60 200fb metam

(VIF)

Pic60 300(Std)

PIC60 300FB metam

(Std)

MB 350(Std)

Treatments

F. O

xysp

orum

cfu

/g

CenterSide

Highest rate of Midas 225 lbs provided 100% control as MeBr and Pic60 fb metam

Field Day in Salina July Field Day in Salina July 20112011

Conclusion: Two Promising alternativesConclusion: Two Promising alternativesMeIMeINo plant mortality was observed and no significant yield reductiNo plant mortality was observed and no significant yield reduction.on.Controlled Controlled FusariumFusarium oxysporumoxysporum as effective as as effective as MeBrMeBr. Higher rate provided 100% . Higher rate provided 100%

control.control.Besides being proven to be strong fungicide, higher rates of MidBesides being proven to be strong fungicide, higher rates of Midas under VIF were as under VIF were

effective weed suppressors equivalent to effective weed suppressors equivalent to MeBrMeBr (88%, 87, respectively) in drip (88%, 87, respectively) in drip application and 85% in shank. Lower rates were not effective on application and 85% in shank. Lower rates were not effective on suppressing weeds. suppressing weeds.

Higher and moderate rates of Midas produced yields equivalent toHigher and moderate rates of Midas produced yields equivalent to MeBrMeBr (100%, 96%). (100%, 96%). No significant changes in the applications methodsNo significant changes in the applications methodsMeIMeI applied at applied at ~~40% rates lower than 40% rates lower than MeBrMeBr, hence, growers can use less chemicals , hence, growers can use less chemicals

while sustaining production and minimize emission. while sustaining production and minimize emission.

DMDSDMDSNo plant mortality was observed and no significant yield reductiNo plant mortality was observed and no significant yield reduction.on.Controlled Controlled V.dahliaeV.dahliae and and PythiumPythium as effective as as effective as MeBrMeBrBesides being proven to be strong fungicide and Besides being proven to be strong fungicide and nematicidenematicide, higher rates of DMDS , higher rates of DMDS

under VIF were effective weed suppressors equivalent to under VIF were effective weed suppressors equivalent to MeBrMeBr (82%).(82%).Higher and moderate rates of DMDS produced yields equivalent to Higher and moderate rates of DMDS produced yields equivalent to MeBrMeBr (97%). (97%). No significant changes in the applications methods. Undergoing rNo significant changes in the applications methods. Undergoing research on shank esearch on shank

application. application. DMDS seems to be a promising and DMDS seems to be a promising and ““attractiveattractive”” alternative with high efficacy and alternative with high efficacy and

potential reduction of buffer zones. Enabled the use of lower potential reduction of buffer zones. Enabled the use of lower PicPic rates.rates.

Thank you very muchThank you very much