Overview of Monsanto’s Volatility Testing
Overview of Monsanto’s Volatility Testing
Monsanto defines assays to measure
volatility
2009 2011Field studies confirm
volatility profile of existing dicamba
formulations
Field drift studies help define application
requirements
2013 2015Monsanto conducted GLP field volatility (flux) studies
Full system launch of Roundup Ready® Crop
System
2017
• Monsanto has conducted extensive volatility testing since 2009– Over 1200 distinct tests in controlled environment (humidome/Hoophouse)– Over 25 field studies (representative of multiple field conditions including varying geographies, temperatures, surfaces)– Studied multiple dicamba formulations (Banvel, Clarity, Xtendimax) including common tank mixes such as glyphosate & AMS
• Consistent findings between controlled environment and field studies• Dicamba-treated fields are not an infinite source of dicamba to the atmosphere
– Majority of dicamba volatilization occurs within 24 hours of application– Measured air concentrations indicates that dicamba dissipates rapidly from the treated area– GLP field volatility studies and PERFUM model confirm findings from previous field and controlled environment studies
• Supporting on-going volatility demonstration trials by academic researchers in multiple states (results expected early fall)
Maximum Minimum AverageUnits °F (°C) °F (°C) °F (°C)
Air Temperature 98.4 (36.9) 70.4 (21.3) 82.2 (27.9)Soil Temperature at1 mm Depth 154.6 (68.1) 72.7 (22.6) 98.2 (36.8)
Units Percent Percent PercentRelative Humidity 99.0 18.0 50.8
Maximum Minimum AverageUnits °F (°C) °F (°C) °F (°C)
Air Temperature 91.4 (33.0) 56.9 (13.8) 71.4 (21.9)Soil Temperature at1 mm Depth 116.8 (47.1) 61.7 (16.5) 83.7 (28.7)
Units Percent Percent PercentRelative Humidity 100 7.7 45.1
GA Field Volatility Conditions—May 2015*
TX Field Volatility Conditions—June 2015
50
55
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90
0 10 700
20
40
60
80
100
Air T
empe
ratur
e(oF
)
Relat
iveHu
midit
y(%)
Monsanto GLP field volatility studies measured flux under worst case conditions
Average Hourly Temperature and Relative Humidity for Georgia Field Volatility Study
20 30 40 50 60Hourly Increments between 7 a.m May 5, 2015 and 7 a.m. May 8, 2015
Percent Relative Humidity Avg Air Temperature Avg
Xtendimax Application
* Soil composition included 88% sand
A finite amount of vapor is available for off-targetmovement
• Peak volatility occurs within first24 hours
• Total dicamba mass loss due tovolatility is very small (~0.05%)for Xtendimax
• These results are consistent with previous research beginning in 2009
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.000
0.001
0.001
0.002
0.002
0.003
0.003
0.004
0.004
0.005
0.005
0 10 20 30 40 50 60 70 80
CumulativeMassL
oss fromField(%
)
Flux
From
Field(µg/m
2 ∙s)
Time Post Application (hours)
Clarity Flux
Clarity Cumulative Mass Loss
Xtendimax Incremental Flux
Xtendimax Cumulative Mass Loss
EPA’s volatility assessment includes compoundinglevels of conservatism• Field studies conducted during “near-idealized” conditions for measuring volatility
– Timing of application, high temperatures, and sandy soil conditions did not underestimate flux• Flux calculated using multiple methods
– Selected worst case (highest) flux value for modeling• Air concentrations were modeled for up to four locations using PERFUM
– Used worst case (highest) estimates for volatility assessment• Effects data were collected in an enclosed humidome
– Overestimates exposure relative to field exposures• EPA concluded that off-site vapor exposures are below NOAEC for non-target plants
Monsanto has conducted additional GLP studies thatfurther support EPA’s findings regarding volatility
Xtendimax + PowerMax Field Volatility Study• Total dicamba mass lost < 0.2%
Refined Humidome Plant Effects• Refined concentration spacing between
NOAEC and LOAEC
0%
3%11 %
19%
25%
42%
52%y = 0.0914x + 1.3333
R² = 0.9794
0
10
20
30
40
50
60
0
7%
100 500 600
Symp
tomolo
gy(%
)
200 300 400Dicamba Acid Air Concentration(ng/m3)
0.000
0.050
0.100
0.150
0.200
0.250
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0 10 20 50 60
Cumulative MassL
ossfrom Field (%
)
Increm
entalM
assL
ossFrom
Field(%
)
30 40Time Post Application (hours)
70Incremental Mass Loss
Cumulative Mass Loss
Monsanto GLP field volatility study with Xtendimax + Powermax measured flux under hot conditions
Parameter Bareground Application OTT ApplicationApplication Rate (lb/A) 0.5 0.5Plot Size (acres) 4.6 9.1Soil type Clay Loam ClaySoil pH 5.5 6.8Soil Moisture at 1/3 bar (%) 32.4 38.8Average Daytime Temperature (oF) 89 88Average Nighttime Temperature (oF) 74 75Maximum Daily Temperature (oF) 91 - 98 91-97Minimum Daily Temperature (oF) 69 - 75 69 - 72Average Soil Temperature (oF) 83.9 83.9Max Soil Temperature (oF) 124.8 124.8Average Relative Humidity (oF) 80.6 80.6Maximum Relative Humidity (oF) 100 100
PERFUM model does not predict levels that would produce symptomology 5 meters outside of the treated fields
10% Symptomology
• Test locations were representative of typical growing areas
• Compared applications to bare ground and in-crop to plant tissue
• Data generated at the highest testingstandards (GLP)
• Modeled air concentration was calculated 5 meters from edge of field
• Dicamba air concentrations outside of the treated field did not demonstrate levels that would produce a visual response
5% Symptomology
5% symptomology is not a reliable or meaningful endpoint• Visual symptomology is unreliable:
– Lack of single universally accepted rating scale
– Subjectivity of ratings between scientists– Symptomology could be due from factors
other than dicamba exposure, especially at low levels
• 5% symptomology equates to slight crinkling in terminal leaves– Terminal bud growth not inhibited; therefore,
no yield impact (Perdue university)• Symptomology >> 5% required to impact
plant height/yield
Drift Field
Soybean symptomology associated with spray drift, volatility, and improper tank cleanout shows a gradient of responses
Weight of evidence indicates dicamba volatility is not sufficient to result in landscape-level symptomology
• Based on Monsanto’s extensive testing and field observations thus far– Confident the magnitude and scope of
symptomology in the fields in 2017 is not attributable to volatility when applying XtendiMax with VaporGrip Technology and following all label requirements
GLP Field Studies
HumidomeScreening
Hoop House
Application Requirements
Technological Advancements
(VaporGrip Technology)
Vapor-phase Plant Effects
Peer-Reviewed Research
Applicator OTM Inquiries - National (as of 9/11/17)
Application Requirement Applicator ReportedDeficiencies
Required Buffer* 643Approved Nozzle 164
Boom Height 147Application Rate 53
Wind Speed 37Application Volume 9
Ground Speed 8
• Most commonly self-reported error is Inadequate Buffer in61% of cases
• Unapproved Nozzles a factor in 15% of cases• Wrong Boom Height a factor in 14% of cases• Some applicators self-reported multiple application errors• Still evaluating 3 of 10 key label requirements:
– Nozzle Pressure– Approved Tank Mix Information– Downwind presence of sensitive crops
• Also evaluating:– Climate Corp’s environmental & weather data on wind
speed, direction and inversion potential– Supporting applicators concerned about possible
contamination through testing• Inversions and proximity to fields where other unapproved
products may be been utilized may be a factor in some cases
*Includes no/inadequate buffer and applicator reported sensitive crop downwind
All are factors that are addressable through training and education
