California's Pesticide Use Reporting System (PUR)
Transcript of California's Pesticide Use Reporting System (PUR)
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
California’s Pesticide Use Reporting System(PUR)
Larry Wilhoit
August 29, 2011
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
1 Pesticide Use Data in Endangered Species Assessments
2 Description of the Pesticide Use Reporting (PUR) system
3 Data Quality
4 Uses and Misuses of the PUR
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Endangered Species Assessments
In endangered species biological opinions, several unlikelyassumptions are made about pesticide use:
Pesticides are applied at maximum label rates
All agricultural areas were assumed to be treated
Treatments can occur at any time of the year
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Pesticide Use Data
With actual data on pesticide use, we can make more realisticassumptions. The PUR has data on:
Actual maximum rates rather maximum rates frompesticide labels
Specific areas where pesticides are used
The dates pesticides are used
The methods of applications
Data exists for more than 20 years
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
History of the PUR
California first required limited reporting of pesticide use in1950.
The PUR database contains records starting in 1974.
Current full use reporting system started in 1990.
The PUR database contains about 2.5 million records foreach year since 1990.
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
What is Reported
All pesticide applications in California productionagriculture must be reported to the appropriate CountyAgricultural Commissioner’s office.
All pesticide applications made by commercial pest controlbusinesses must be reported.
The exceptions: pesticide applications made by home andgarden use or most institutional use are not reported.
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Two Types of PUR Records
Production agricultural applications
Applications to agricultural fieldsCalifornia defines agriculture broadly, including forests,parks, rangelands, turfEach record in the PUR refers to one application
Monthly summary reports
All other uses by commercial applicators (post harvest,landscape, structural)Each record refers to total use of a pesticide during eachmonth on a site in a county by the applicator
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Data Collected for Production Agricultural Records
Pesticide product used (its name and EPA registrationnumber)Amount of product used, in gallons, pounds, or other unitsCrop treatedArea of the crop plantedArea of the crop treatedDate of treatmentGeographic location of the treatment (to a square mile)Grower or operator identifierField identifierMethod of application (by air, ground, or other method)
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Process from Grower to DPR Database
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Importance of Error Screening
It is critical that the PUR be as accurate and complete aspossible.
Even a few errors can have large effects on an analysis.
The PUR is screened for about 40 kinds of errors.
Error rate is less than 0.5%.
Probably 80 to 90% of actual use is reported.
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Common Errors in the PUR
Units of measures (ga, qt, oz)
Units treated (acres, square feet, cubic feet, pounds)
Amount applied
Product name or registration number
Duplicate records
Errors in DPR’s label database
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Errors Affecting Rate of Use
Many of these errors affect rate of use (pounds applied perarea treated).
Indentifying rate errors is difficult because rates depend onthe pesticide, crop treated, and many other things.
An unusual reported rate is not necessarily an error—highor low rates are sometimes used.
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Identifying Rate Outliers
Maximum label rates
Fixed limits for most AIs and high rate AIs and for eachkind of unit treated
Median of the log (rate * 50) of similar uses
Trimmed mean log rate + 8 * standard deviation
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Visual Inspections of DistributionsGlyphosate
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
PUR vs Sales Data
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Pounds of 2,4-D by Crop, County, Month, and Year
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Map of Thiobencarb Use In Colusa Area by Section
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Maximum Label Rates vs Actual RatesGlyphosate
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Forecasting Pounds of ChlorothalonilWith 80% and 95% prediction intervals
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Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Strengths of PUR
PUR data includes detailed records of each agriculturalapplication.
Data are obtained from a census not just samples.
Data are GIS friendly.
Data can be linked with many other databases on thechemical, environmental, and health properties ofpesticides.
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Misuses of the PUR
Failing to check for errors in your dataset
Misunderstanding of some of the data: eg acre_treatedand acre_planted do not always mean acres
Confusing pesticide products with active ingredients
Comparing extent of use of different AIs using only poundsMethyl bromide is used at rates about 230 lbs/acre
Esfenvalerate is used at rates about 0.04 lbs/acre
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Limitations of the PURMissing Information
Does not include most applications to animals and tonon-agricultural sites
No pest information
No date of planting or harvest
No information on person or business making agriculturalapplications
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Conclusion
The PUR is a valuable source of high quality and detaileddata on pesticide use, especially in production agriculture.
Users of the data need to be aware of some of thelimitations in the data.
The PUR can be used to make more realistic and accurateassessments of the exposure of pesticides to endangeredspecies.
Outline PUR and Endangered Species Description of the PUR Data Quality Uses and Misuses of the PUR Conclusion
Any Questions?