Summary of Pesticide Use Report Data - 2009

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CALIFORNIA DEPARTMENT OF PESTICIDE REGULATION
California Environmental Protection Agency
1001 I Street
Sacramento, California 95814-3510
Arnold Schwarzenegger, Governor
Linda S. Adams, Secretary for Environmental Protection
Mary-Ann Warmerdam, Director
Department of Pesticide Regulation
State Seal

December 2010

Any portion of this report may be reproduced for any but profit-making purposes. For information for obtaining electronic data files, see Page iii. This report can also be downloaded from DPR’s FTP site. If you have questions concerning this report, call (916) 445-3887.

TABLE OF CONTENTS

How To Access The Summary Of Pesticide Use Report Data

I.  INTRODUCTION

II.  COMMENTS AND CLARIFICATIONS OF DATA

III.  DATA SUMMARY

IV.  TRENDS IN USE IN CERTAIN PESTICIDE CATEGORIES

V.  TRENDS IN PESTICIDE USE IN CERTAIN COMMODITIES

VI.  SUMMARY OF PESTICIDE USE REPORT DATA 2009 INDEXED BY COMMODITY (PDF, 1.9 mb)

VII.  SUMMARY OF PESTICIDE USE REPORT DATA 2009 INDEXED BY CHEMICAL (PDF, 1.9 mb)


How to Access the Summary of Pesticide Use Report Data

The Summary of Pesticide Use Report Data indexed by chemical or commodity reports for years 1989-2009 can be found on DPR’s Web site. The Summary of Pesticide Use Report Data is available in two formats. One report is indexed by chemical and lists the amount of each pesticide used, the commodity on which it was used, the number of agricultural applications, and the acres/units treated. The second report is indexed by commodity and lists the chemicals used, the number of agricultural applications, amount of pesticides used, and the acres/units treated.

The Annual Pesticide Use Report Data (the complete database of reported pesticide applications for 1990-2009) are available on CD. The files are in text (comma-delimited) format.

The complete Pesticide Use Report database (Zip files by year, 1974 to current year) may be downloaded from DPR’s FTP site .

Questions regarding the Summary of Pesticide Use Report Data should be directed to: Department of Pesticide Regulation, Pest Management and Licensing Branch, P.O. Box 4015, Sacramento, California 95812 -4015.Telephone (916)445-3887 or e-mail to mwilliams@cdpr.ca.gov.


I. INTRODUCTION

Development and Implementation of the Pesticide Use Reporting System

The 2009 Summary of Pesticide Use Report Data includes agricultural applications and other selected uses reported in California. The report represents a summary of the data gathered under full use reporting. The Department of Pesticide Regulation (DPR) uses the data to help estimate dietary risk and to ensure compliance with clean air laws, as well as ground water protection regulations. Site-specific use report data, combined with geographic data on endangered species habitats, also help county agricultural commissioners resolve potential pesticide use conflicts. Detailed pesticide use report (PUR) data may be obtained from DPR for in-depth, analytical purposes.

Under full use reporting, which began in 1990, California became the first state to require reporting of all agricultural pesticide use, including amounts applied and types of crops or places (e.g., structures, roadsides) treated. Commercial applications-including structural fumigation, pest control, and turf applications-must also be reported. Pesticide use reporting is explained in more detail below.

Types of Pesticide Applications Reported

Partial reporting of agricultural pesticide use has been in place in California since at least the 1950s. Beginning in 1970, anyone who used restricted materials was required to file a pesticide use report with the county agricultural commissioner. The criteria established to designate a pesticide as a restricted material include potential hazard to:

  • public health
  • farm workers
  • domestic animals
  • honeybees
  • the environment
  • wildlife
  • other crops

With certain exceptions, restricted materials may be possessed or used only by, or under the supervision of, licensed or certified persons, and only in accordance with an annual permit issued by a county agricultural commissioner.

In addition, the State required commercial pest control operators1 to report all pesticides used, whether restricted or nonrestricted. These reports included information about the pesticide applied, when and where the application was made, and the crop involved if the application was in agriculture. The reports were entered into a computerized database and summarized by chemical and crop in annual reports.

With implementation of full use reporting in 1990, the following pesticide uses are required to be reported to the commissioner who, in turn, reports the data to DPR:

  • For the production of any agricultural commodity, except livestock.
  • For the treatment of postharvest agricultural commodities.
  • For landscape maintenance in parks, golf courses, and cemeteries.
  • For roadside and railroad rights-of-way.
  • For poultry and fish production.
  • Any application of a restricted material.
  • Any application of a pesticide with the potential to pollute ground water (listed in section 6800(b) of the California Code of Regulations, Title 3, Division 6, Chapter 4, Subchapter 1, Article 1) when used outdoors in industrial and institutional settings.
  • Any application by a licensed pest control operator.

The primary exceptions to the use reporting requirements are home and garden use and most industrial and institutional uses.


1 Pest control operators include those in the business of applying pesticides such as agricultural applicators, structural fumigators, and professional gardeners.

How Pesticide Data Are Used

DPR undertook the expansion of use reporting primarily in response to concerns of many individuals and groups, including government officials, scientists, farmers, legislators, and public interest groups.

The following are examples of how pesticide use reporting data are used in risk assessment; the protection of workers, public health, endangered species, and water and air quality; pest management assessments; and processor and retailer requirements.

Risk Assessment

Without information on actual pesticide use, regulatory agencies conducting risk assessment assume all planted crop acreage is treated with many pesticides, even though most crops are treated with just a few chemicals. If the assumptions used by regulatory agencies are incorrect, regulators could make judgments on pesticide risks that are too cautious by several orders of magnitude, reducing the credibility of risk management decisions. The use report data, on the other hand, provides actual use data so DPR can better assess risk and make more realistic risk management decisions.

After the passage of the federal Food Quality Protection Act (FQPA) in 1996, complete pesticide use data became even more important to commodity groups in California and to the U.S. Environmental Protection Agency (U.S. EPA). FQPA contained a new food safety standard against which all pesticide tolerances must be measured. The increased interest in the state’s pesticide use data, especially for calculating percent crop treated, came at a time when DPR was increasing the efficiency with which it produced its annual report. DPR was able to provide up-to-date use data and summaries to commodity groups, University of California specialists, U.S. EPA programs, and other interested parties as they developed the necessary information for the reassessment of existing tolerances.

Worker Health and Safety

Under the pesticide regulations [section 6619 of the Title 3 California Code of Regulations, Division 6, Chapter 3, Subchapter 2, Article 1], pest control operators must give farmers a written notice after every pesticide application that includes the pesticide applied, the location of the application, the date and time the application was completed, and the reentry and preharvest intervals.2 This notice gives the farmer accurate information to help keep workers from entering fields prematurely, and also lets the farmer know the earliest date a commodity can be harvested.

DPR’s Worker Health and Safety Branch also uses the data for worker exposure assessment as part of developing an overall risk characterization document. Use data helps scientists estimate typical applications and how often pesticides are used.


2 A reentry interval is the time from which a pesticide application is made and when workers may enter a field. A preharvest interval is the time between an application and when a commodity can be harvested.

Public Health

The expanded reporting system provides DPR, the State Department of Public Health, and the Office of Environmental Health Hazard Assessment with more complete pesticide use data for evaluating possible human illness clusters in epidemiological studies.

Endangered Species

DPR works with the county agricultural commissioners to combine site-specific use report data with geographic information system-based data on locations of endangered species. The resulting database helps commissioners resolve potential conflicts over pesticide use where endangered species may occur. DPR and the commissioners can also examine patterns of pesticide use near habitats to determine the potential impact of proposed use limitations. With location-specific data on pesticide use, restrictions on use can be better designed to protect endangered species while still allowing necessary pest control.

Water Quality

Since 1983, DPR has had a program to work with the rice growing industry and the Central Valley Regional Water Quality Control Board to reduce contamination of surface water by rice pesticides. Using PUR data to help in pinpointing specific agricultural practices, more precise alternative use recommendations can be made to assure protection of surface water.

The Pesticide Contamination Prevention Act requires site-specific records to help track pesticide use in areas known to be susceptible to ground water contamination. Determinations can also be made from the records on whether a contaminated well is physically associated with agricultural practices. These records also provide data to help researchers determine why certain soil types are more prone to ground water contamination.

DPR placed certain pesticide products containing pyrethroids into reevaluation on August 31, 2006. The reevaluation is based on recent studies revealing the widespread presence of synthetic pyrethroid residues in the sediment of California waterways at levels toxic to an aquatic crustacean. Use report data are used to refine water quality monitoring strategies and to help focus mitigation efforts, such as those proposed in DPR’s surface water regulatory concepts, on specific active ingredients or commodities or in particular watersheds.

Air Quality

Many pesticide products contain volatile organic compounds (VOCs) that contribute to the formation of smog. DPR worked with the state Air Resources Board to put together a State Implementation Plan under the federal Clean Air Act to reduce emissions of all sources of VOCs, including pesticides, in nonattainment areas of the state. DPR’s contribution to the plan included accurate data on the amount of VOCs contained in pesticides and the ability to inventory the use of those pesticides through pesticide use reporting.

Beginning in January 2008, regulations went into effect to reduce emissions of VOCs from fumigant pesticides. To help DPR keep track of these smog-producing emissions, PURs are used to monitor fumigant use and methods of fumigant application. This information is then used to compare with targeted emission reduction goals designed to improve air quality.

Pest Management

The Department uses the PUR database to understand patterns and changes in pest management. This information can be used to determine possible alternatives to pesticides that are subject to regulatory actions and to help determine possible impacts of different regulatory actions on pest management.

The PUR is used to help meet the needs of FQPA, which requires pesticide use information for determining the appropriateness of pesticide residue tolerances. As part of this process many commodity groups have created crop profiles, which include information on the pest management practices and available options, both chemical and nonchemical. Pesticide use data is critical to developing these lists of practices and options.

The PUR data have been used to support and assess grant projects for the Alliance grant program conducted by DPR to develop, demonstrate, and implement reduced-risk pest management strategies from 1995 to 2003. The PUR data have been used in several other projects that build on work conducted in the almond and stone fruit industries. In these and other projects, the PUR data are used to address regional pesticide use patterns and environmental problems such as water and air quality. The data are also used to better understand current changes in pesticide use.

DPR has published general analyses of statewide pesticide use patterns and trends. The first analysis covered the years 1991 to 1995, and the second more detailed analysis covered 1991 to 1996. These analyses identified high-use pesticides, the crops to which those pesticides were applied, trends in use, and the pesticides most responsible for changes in use. In addition, since 1997, the annual Summary of Pesticide Use Report Data include summary trends of pesticides in several different categories such as carcinogens, reproductive toxins, and ground water contaminants.

Processor and Retailer Requirements

Food processors, produce packers, and retailers often require farmers to submit a complete history of pesticide use on crops. DPR’s use report form often satisfies this requirement.




II. COMMENTS AND CLARIFICATIONS OF DATA

The following comments and points should be taken into consideration when analyzing data contained in this report.

Terminology

Number of agricultural applications – Number of applications of pesticide products made to production agriculture. More detailed information is given below under "Number of Applications."

Pounds applied – Number of pounds of an active ingredient.

Unit type – The amount listed in this column is one of the following:
A = Acreage
C = Cubic feet (of commodity treated)
K = Thousand cubic feet (of commodity treated)
P = Pounds (of commodity treated)
S = Square feet
T = Tons (of commodity treated)
U = Miscellaneous units (e.g., number of tractors, trees, tree holes, bins, etc.)

Commodity Codes

DPR’s pesticide product label database is used to cross-check data entries to determine if the product reported is registered for use on the reported commodity. The DPR label database uses a crop coding system based on crop names used by the U.S. EPA to prepare official label language. However, this system caused some problems until DPR modified it in the early 1990s to account for U.S. EPA’s grouping of certain crops under generic names. Problems occurred when the label language in the database called a crop by one name, and the use report used another. For example, a grower may have reported a pesticide use on "almonds," but the actual label on the pesticide product-coded into the database-stated the pesticide was to be used on "nuts." DPR modified the database to eliminate records being rejected as "errors" because the specific commodity listed on the use report is not on the label. A qualifier code is appended to the commodity code in the label database to designate a commodity not specifically listed on the label as a correct use. A qualifier code would be attached to the "almond" code when nuts are only listed on the label. This system greatly reduces the number of rejections.

Plants and commodities grown in greenhouse and nursery operations represented a challenge in use reporting because of their diversity. Six commodity groupings were suggested by industry in 1990 and incorporate terminology that are generally known and accepted. The six use reporting categories are: greenhouse-grown cut flowers or greens; outdoor-grown cut flowers or greens; greenhouse-grown plants in containers; outdoor-grown plants in container/field-grown plants; greenhouse-grown transplants/propagative material; and outdoor-grown transplants/propagative material.

Tomatoes and grapes were also separated into two categories because of public and processor interest in differentiating pesticide use. Tomatoes are assigned two codes to differentiate between fresh market and processing categories. One code was assigned to table grapes, which includes grapes grown for fresh market, raisins, canning, or juicing. A second code was assigned to wine grapes.

Unregistered Use

The report contains entries that reflect the use of a pesticide on a commodity for which the pesticide is not currently registered. This sometimes occurs because the original use report was in error, that is, either the pesticide or the commodity was inaccurately reported. DPR’s computer program checks that the commodity is listed on the label, but nonetheless such errors appear in the PUR, possibly because of errors in the label database. Also, the validation program does not check whether the pesticide product was registered at the time of application. For example, parathion (ethyl parathion) is shown reported on crops after most uses were suspended in 1992. (These records are researched and corrected as time and resources allow.) DPR continues to implement methods that identify and reduce these types of reporting errors in future reports. Other instances may occur because by law, growers are sometimes allowed to use stock they have on hand of a pesticide product that has been withdrawn from the market by the manufacturer or suspended or canceled by regulatory authorities.

Other reporting "errors" may occur when a pesticide is applied directly to a site to control a particular pest, but is not applied directly to the crop in the field. A grower may use an herbicide to treat weeds on the edge of a field, a fumigant on bare soil prior to planting, or a rodenticide to treat rodent burrows. For example, reporting the use of the herbicide glyphosate on tomatoes-when it was actually applied to bare soil prior to planting the tomatoes-could be perceived to be an error. Although technically incorrect, recording the data as if the application were made directly to the commodity provides valuable crop usage information for DPR’s regulatory program.

Adjuvants

Data on spray adjuvants (including emulsifiers, wetting agents, foam suppressants, and other efficacy enhancers), not reported prior to full use reporting, are now included. Examples of these types of chemicals include the "alkyls" and some petroleum distillates. (Adjuvants are exempt from federal registration requirements, but must be registered as pesticides in California.)

Zero Pounds Applied

There are a few entries in this report in which the total pounds applied for certain active ingredients are displayed as zero. This is because the chemical (active ingredient) made up a very small percentage of the formulated product that was used. When these products are applied in extremely low quantities, the resulting value of the active ingredient is too low to register an amount.

Acres Treated

The summary information in this annual report cannot be used to determine the total number of acres of a crop. However, it can be used to determine the cumulative acres treated. The problem is that the same field can be treated more than once in a year with the same active ingredient. A similar problem occurs when the product used contains more than one active ingredient. (In any pesticide product, the active ingredient is the component that kills, or otherwise controls, target pests. A pesticide product is made up of one or more active ingredients, as well as one or more inert ingredients.) For example, if a 20-acre field is treated with a product that contains three different pesticide active ingredients, a use report is filed by the farmer correctly recording the application of a single pesticide product to 20 acres. However, in the summary tables, the three different active ingredients will each have recorded 20 acres treated. Adding these values results in a total of 60 acres as being treated instead of the 20 acres actually treated.

Number of Applications

The values for number of applications include only production agricultural applications. Applicators are required to submit one of two basic types of use reports, a production agricultural report or a monthly summary report. The production agricultural report must include information for each application. The monthly summary report, for all uses other than production agriculture, includes only monthly totals for all applications of pesticide product, site or commodity, and applicator. The total number of applications in the monthly summary reports is not consistently given so they are no longer included in the totals. In the annual PUR reports before 1997, each monthly summary record was counted as one application.

In the annual summary report by commodity, the total number of applications given for each commodity may not equal the sum of all applications of each active ingredient on that commodity. As explained above, some pesticide products contain more than one active ingredient. If the number of applications were summed for each active ingredient in such a product, the total number of applications would be more than one, even though only one application of the product was made.

Errors

In any database with millions of records there will almost certainly be errors. Most of the values in the PUR are checked for errors and, where possible, corrections are made. However, some errors will remain. If a value is completely unknown the value will either be left blank for numeric fields or replaced with a "?" or "UNKNOWN" in character fields.

If a reported rate of use (pounds of pesticide per area treated) was so large it was probably in error, the rate was replaced with an estimated rate equal to the median rate of all applications of the pesticide product on the same crop or other site treated. Since the error could have been in the pounds reported or the area or unit treated, the value that was most unusual was the one replaced with an estimate. In some cases, a reasonable estimate could not be made, for example, if there were no or few other reported applications of the product on the site. In these cases, the pounds value was set equal to 0.

Pesticide rates were considered outliers if (1) they were higher than 200 pounds of active ingredient per acre (or greater than 1,000 pounds per acre for fumigants); (2) they were 50 times larger than the median rate for all uses with the same pesticide product, crop treated, unit treated, and record type (that is, production agricultural or all other uses); or (3) they were higher than a value determined by a neural network procedure that approximates what a group of 12 scientists believed were obvious outliers. Although these criteria identified as outliers less than one percent of the rate values in the PUR, some rates were so large that if included in the sums, they would have significantly affected total pounds applied of some pesticides.




III. DATA SUMMARY

This report is a summary of data submitted to DPR. Total pounds may change slightly due to ongoing error correction. The revised numbers, when available, will more accurately reflect the total pounds applied.

Pesticide Use In California

In 2009, there were 155,869,703 pounds of pesticide active ingredients reported used in California. Annual use has varied from year to year since full use reporting was implemented in 1990. For example, reported pesticide use was 180 million pounds in 2004, 188 million pounds in 2006, and 164 million pounds in 2008.

Such variances are and will continue to be a normal occurrence. These fluctuations can be attributed to a variety of factors, including changes in planted acreage, crop plantings, pest pressures, and weather conditions. For example, extremely heavy rains result in excessive weeds, thus more pesticides may be used; drought conditions may result in fewer planted acres, thus less pesticide may be used.

In addition, it should be noted that the pounds of pesticides used and the number of applications are not necessarily accurate indicators of the extent of pesticide use or, conversely, the extent of use of reduced-risk pest management methods. For example, farmers may make a number of small-scale " spot" applications targeted at problem areas rather than one treatment of a large area. They may replace a more toxic pesticide used at one pound per acre with a less hazardous compound that must be applied at several pounds per acre. Either of these scenarios could increase the number of applications or amount of pounds used, respectively, without indicating an increased reliance on pesticides.

As in previous years, the greatest pesticide use occurred in California’s San Joaquin Valley (Table 1). The four counties in this region with the highest use were Fresno, Kern, Tulare, and San Joaquin.

Table 2 breaks down the pounds of pesticide use by general use categories: production agriculture, post-harvest commodity fumigation, structural pest control, landscape maintenance, and all others.

Table 1: Total pounds of pesticide active ingredients reported in each county and rank during 2008 and 2009.

 

Table 2: Pounds of pesticide active ingredients, 1998 - 2009, by general use categories.

Pesticide Sales In California

Reported pesticide applications are only a portion of the pesticides sold each year. Typically, about two-thirds of the pesticide active ingredients sold in a given year are not subject to use reporting. Examples of non-reported active ingredients are chlorine (used primarily for municipal water treatment) and home-use pesticide products.

Sales data for 2009 will be released in January 2011. There were 729 million pounds sold in 2008, 678 million pounds sold in 2007, 743 million pounds sold in 2006, and 611 million pounds in 2005. Prior-years data are posted on DPR’s web site, click "A - Z Index," "Sales of pesticides."

 

IV. TRENDS IN USE IN CERTAIN PESTICIDE CATEGORIES

Reported pesticide use in California in 2009 totaled 156 million pounds, a decrease of nearly 8 million pounds from 2008. Production agriculture, the major category of use subject to reporting requirements, accounted for most of the overall decrease in use. Applications decreased by 5.1 million pounds for production agriculture. Similarly, there was a 1.3 million-pound decrease in post-harvest treatments, a 318,000-pound decrease in structural pest control, 290,000-pound decrease in landscape maintenance, and 973,000-pound decrease of other reported non-agricultural uses, which includes rights of way, vector control, research, and fumigation of nonfood and nonfeed materials such as lumber and furniture.

The active ingredients (AI) with the largest uses by pounds in 2009 were sulfur, petroleum and mineral oils, metam-sodium, glyphosate, and 1,3-dichloropropene (1,3-D). Sulfur was the most highly used non-adjuvant pesticide in 2009, both in pounds applied and acres treated. By pounds, sulfur accounted for 27 percent of all reported pesticide use. Sulfur is a natural fungicide favored by both conventional and organic farmers.

Most of the decline in reported pesticide use was from 1,3-dichloropropene (1,3-D), which decreased by 3.5 million pounds (36 percent). Other non-adjuvant pesticides that declined in use include petroleum and mineral oils (1.7 million-pound decrease, 6.0 percent), potassium N- methyldithiocarbamate (also called metam-potassium) (1.4 million-pound decrease, 26 percent), copper-based pesticides (947,000-pound decrease, 16 percent), chlorine (693,00-pound decrease, 54 percent), and metam-sodium (665,000-pound decrease, 7.0 percent).

In contrast, some pesticide use increased. Non-adjuvant pesticides with the greatest increase in pounds applied were sulfur (1.6 million-pound increase, 4 percent), kaolin (856,000-pound increase, 59 percent), pendimethalin (320,000-pound increase, 22 percent), oxyfluorfen (266,000- pound increase, 39 percent), and phosphine (215,000-pound increase, 447 percent).

Major crops or sites that showed an overall increase in pesticide pounds applied from 2008 to 2009 include processing tomato (3.0 million-pound increase, 26 percent), wine grape (668,000 pounds, 3 percent), pomegranate (639,000 pounds, 218 percent), and pistachio (599,000 pounds, 25 percent). Major crops or sites with decreased pounds applied include carrot (4.2 million-pound decrease, 44 percent), table and raisin grape, (1.1 million pounds, 8 percent), cotton (982,000 pounds, 40 percent), orange (929,000 pounds, 10 percent), and almond (721,000 pounds, 4 percent). Acreage of most of these crops increased (Table 3). For most crops the change in acreage and pounds applied were in the same direction. However, for almonds and oranges acreage increased but pounds applied decreased.

Table 3: The change in pounds of AI applied and acres planted or harvested and the percent change from 2008 and 2009 for the crops or sites with the greatest change in pounds applied.

DPR data analyses have shown that pesticide use varies from year to year depending upon pest problems, weather, acreage and types of crops planted, economics, and other factors. Of the different AI types, fumigants had the greatest decrease in pounds of AI, though only a small decrease by acres treated. Insecticide use had the second largest decrease by pounds and the largest decrease by acres treated. Fungicide use declined by pounds applied but acres treated increased. Conversely, pounds of herbicide increased slightly but acres treated decreased.

Pesticide use is reported as the number of pounds of AI and the total number of acres treated. The data for pounds include both agricultural and nonagricultural applications; the data for acres treated are primarily agricultural applications. The number of acres treated means the cumulative number of acres treated; the acres treated in each application are summed even when the same field is sprayed more than once in a year. (For example, if one acre is treated three times in a season with an individual AI, it is counted as three acres treated in the tables and graphs in Sections IV and V of this report.)

To provide an overview, pesticide use is summarized for eight different pesticide categories from 2000 to 2009 (Tables 4 - 19) and from 1994 to 2009 (Figures 1 - 8). These categories classify pesticides according to certain characteristics such as reproductive toxins, carcinogens, or reduced- risk characteristics. Use of all pesticide categories decreased from 2008 to 2009, except for a small increase in pounds of biopesticides. Some of the major changes from 2008 to 2009 include:

  • Chemicals classified as reproductive toxins decreased in pounds applied from 2008 to 2009 (998,000 pounds or 6 percent) and decreased in acres treated (down 146,000 acres or 9 percent). The decrease in pounds was mostly from the reduced use of the fumigants metam-sodium, methyl bromide, and sodium tetrathiocarbonate. The decrease in acres was mostly from decreases in the insecticide oxydemeton-methyl, the herbicide bromoxynil octanoate, and the fungicide myclobutanil. Pesticides in this category are ones listed on the State’s Proposition 65 list of chemicals "known to cause reproductive toxicity."
  • Use of chemicals classified as carcinogens decreased significantly from 2008 to 2009 (down 4.5 million pounds or 19 percent and down 280,000 acres or 8 percent). The decrease in pounds was mainly due to decreases in use of the fumigants 1,3-dichloropropene and metam-sodium. The decrease in acres treated was mostly from decreases in the herbicide diuron and the fungicide maneb. The pesticides in this category are ones listed by U.S. EPA as B2 carcinogens or on the State’s Proposition 65 list of chemicals "known to cause cancer."
  • Use of cholinesterase-inhibiting pesticides (organophosphate [OP] and carbamate pesticides), which include compounds of high regulatory concern, continued to decline as they have for nearly every year since 1995. Use decreased from 2008 to 2009 both in pounds (down 881,000 or 17 percent) and in acres treated (down 918,000 acres or 21 percent). The AIs with the greatest decreases in pounds were phosmet, chlorpyrifos, and diazinon; the AIs with the greatest decreases in acres treated were chlorpyrifos, diazinon, and ethephon.
  • Use of most chemicals categorized as ground water contaminants decreased by pounds (down 182,000 pounds or 14 percent), and by acres treated (down 114,000 acres or 12 percent) in 2009 compared to 2008. The decreases in pounds and acres treated were mostly from decreases in use of the herbicide diuron.
  • Chemicals categorized as toxic air contaminants, another group of pesticides of regulatory concern, decreased from 2008 to 2009 both in pounds (down 6.7 million pounds or 18 percent) and by acres treated (down 235,000 acres or 8 percent). By pounds, most toxic air contaminants are fumigants, which are used at high rates. By acres treated, the main decreasing AIs were the herbicide trifluralin and the fungicide maneb.
  • The pounds of fumigant chemicals applied decreased in 2009 from 2008 (down 5.4 million pounds or 14 percent) and decreased in cumulative acres treated (down 6,000 acres or 2 percent). Pounds of four of the six major fumigants decreased (1,3-D, potassium N-methyldithiocarbamate, metam-sodium, and methyl bromide) and pounds of two fumigants increased (chloropicrin and sulfuryl fluoride).
  • Pounds of oil pesticides decreased (down 1.7 million pounds or 6 percent) and decreased by acres treated (down 126,000 acres or 4 percent). Oils include many different chemicals, but the category used here includes only ones derived from petroleum distillation. Some of these oils may be on the State ’s Proposition 65 list of chemicals “known to cause cancer” but most serve as alternatives to highly toxic pesticides. Oils are also used by organic growers.
  • Pounds of biopesticides increased slightly in 2009 compared to 2008 (up 26,000 pounds or 2 percent) but decreased by acres treated (down 153,000 acres or 6 percent) from 2008 to 2009. The most-used biopesticide by pounds was Bacillus thuringiensis (combining all subspecies) and the most- used by acres treated were gibberellins, propylene glycol, and Bacillus thuringiensis. Potassium bicarbonate had the largest increase by pounds and acres treated. The AIs with the greatest decreases in acres treated were propylene glycol and Bacillus thuringiensis. Biopesticides include microorganisms and naturally occurring compounds, or compounds essentially identical to naturally occurring compounds not toxic to the target pest, such as pheromones, which are used to disrupt insect mating.

Since 1993, the reported pounds of pesticides applied have fluctuated from year to year. An increase or decrease in use from one year to the next or in the span of a few years does not necessarily indicate a general trend in use; it simply may reflect variations related to various factors (e.g. climate or economic changes). Short periods of time (three to five years) may suggest trends, such as the increased pesticide use from 2001 to 2005 or the decreased use from 1998 to 2001. However, regression analyses on use from 1993 to 2009 do not indicate a significant trend of either increase or decrease in total pesticide use.

To improve data quality when calculating the total pounds of pesticides, DPR excluded values that were so large they were probably in error. The procedure to exclude probable errors involved the development of complex error-checking algorithms, a data improvement process that is ongoing.

Over-reporting errors have a much greater impact on the numerical accuracy of the database than under-reporting errors. For example, if a field is treated with 100 pounds of a pesticide AI and the application is erroneously recorded as 100,000 pounds (a decimal point shift of three places to the right), an error of 99,900 pounds is introduced into the database. If the same degree of error is made in shifting the decimal point to the left, the application is recorded as 0.1 pound, and an error of 99.9 pounds is entered into the database.

The summaries detailed in the following use categories are not intended to serve as indicators of pesticide risks to the public or the environment. Rather, the data supports DPR regulatory functions to enhance public safety and environmental protection. (See “How Pesticide Data are Used” on page 2.)

 

USE TRENDS OF PESTICIDES ON THE STATE’S PROPOSITION 65 LIST OF CHEMICALS THAT ARE "KNOWN TO CAUSE REPRODUCTIVE TOXICITY"

Table 4: The reported pounds of pesticides used that are on the State’s Proposition 65 list of chemicals that are “known to cause reproductive toxicity. ” Use includes both agricultural and reportable non- agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 5: The reported cumulative acres treated with pesticides that are on the State’s Proposition 65 list of chemicals that are “known to cause reproductive toxicity.” Use includes primarily agricultural applications. The grand total for acres treated may be less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Figure 1: Use trends of pesticides that are on the Stat’s Proposition 65 list of chemicals that are "known to cause reproductive toxicity." Reported pounds of active ingredient (AI) applied include both agricultural and non-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports

 

USE TRENDS OF PESTICIDES LISTED BY U.S. EPA AS B2 CARCINOGENS OR ON THE STATE’S PROPOSITION 65 LIST OF CHEMICALS THAT ARE "KNOWN TO CAUSE CANCER"

Table 6: The reported pounds of pesticides used that are listed by U.S. EPA as B2 carcinogens or on the State’s Proposition 65 list of chemicals that are “known to cause cancer.” Use includes both agricultural and reportable non--agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 7: The reported cumulative acres treated with pesticides that are listed by U.S. EPA as B2 carcinogens or on the State’s Proposition 65 list of chemicals that are “known to cause cancer.” Use includes primarily agricultural applications. The grand total for acres treated may be less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Figure 2: Use trends of pesticides that are listed by U.S. EPA as B2 carcinogens or on the Stat’s Proposition 65 list of chemicals that are "known to cause cancer." Reported pounds of active ingredient (AI) applied include both agricultural and non-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports

 

USE TRENDS OF PESTICIDES CHOLINESTERASE-INHIBITING PESTICIDES

Table 8: The reported pounds of pesticides used that are cholinesterase-inhibiting pesticides. These pesticides are organophosphate and carbamate active ingredients. Use includes both agricultural and reportable non- agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 9: The reported cumulative acres treated with pesticides that are cholinesterase-inhibiting pesticides. These pesticides are organophosphate and carbamate active ingredients. Use includes primarily agricultural applications. The grand total for acres treated may be less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Figure 3: Use trends of pesticides that are cholinesterase-inhibiting pesticides. These pesticides are organophosphate and carbamate active ingredients. Reported pounds of active ingredient (AI) applied include both agricultural and no-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

 

USE TRENDS OF PESTICIDES ON THE "A" PART OF DPR’S GROUND WATER PROTECTION LIST

Table 10: The reported pounds of pesticides used that are on the "a" part of DPR’s groundwater protection list. These pesticides are the active ingredients listed in the California Code of Regulations, Title 3, Division 6, Chapter 4, Subchapter 1, Article 1, Section 6800(a). Use includes both agricultural and reportable non-agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 11: The reported cumulative acres treated with pesticides that are on the "a" part of DPR’s groundwater protection list. These pesticides are the active ingredients listed in the California Code of Regulations, Title 3, Division 6, Chapter 4, Subchapter 1, Article 1, Section 6800(a). Use includes primarily agricultural applications. The grand total for acres treated may be less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Figure 4: Use trends of pesticides that are the "a" part of DPR’s groundwater protection list. These pesticides are the active ingredients listed in the California Code of Regulations, Title 3, Division 6, Chapter 4, Subchapter 1, Article 1, Section 6800(a). Reported pounds of active ingredient (AI) applied include both agricultural and non-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

 

USE TRENDS OF PESTICIDES ON DPR’S TOXIC AIR CONTAMINANTS LIST APPLIED IN CALIFORNIA

Table 12: The reported pounds of pesticides on DPR’s toxic air contaminants list applied in California. These pesticides are the active ingredients listed in the California Code of Regulations, Title 3, Division 6, Chapter 4, Subchapter 1, Article 1, Section 6860. Use includes both agricultural and reportable non-agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 13: The reported cumulative acres treated in California with pesticides on DPR’s toxic air contaminants list. These pesticides are the active ingredients listed in the California Code of Regulations, Title 3, Division 6, Chapter 4, Subchapter 1, Article 1, Section 6860. Use includes primarily agricultural applications. The grand total for acres treated is less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Figure 5: Use trends of pesticides that are on DPR’s toxic air contaminants list applied in California. These pesticides are the active ingredients listed in the California Code of Regulations, Title 3, Division 6, Chapter 4, Subchapter 1, Article 1, Section 6860. Reported pounds of active ingredient (AI) applied include both agricultural and non-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

 

USE TRENDS OF PESTICIDES THAT ARE FUMIGANTS

Table 14: The reported pounds of pesticides used that are fumigants. Use includes both agricultural and reportable non-agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 15: The reported cumulative acres treated with pesticides that are fumigants. Use includes primarily agricultural applications. The grand total for acres treated may be less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Figure 6: Use trends of pesticides that are fumigants. Reported pounds of active ingredient (AI) applied include both agricultural and non-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

 

USE TRENDS OF PESTICIDES OILS.

Table 16: The reported pounds of oil pesticides. As a broad group, oil pesticides and other petroleum distillates are on U.S. EPA’s list of B2 carcinogens or the State’s Proposition 65 list of chemicals “known to cause cancer.” However, these classifications do not distinguish among oil pesticides that may not qualify as carcinogenic due to their degree of refinement. Many such oil pesticides also serve as alternatives to high-toxicity chemicals. For this reason, oil pesticide data was classified separately in this report. Use includes both agricultural and reportable non-agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 17: The reported cumulative acres treated with pesticides that are oils. As a broad group, oil pesticides and other petroleum distillates are on U.S. EPA’s list of B2 carcinogens or the State’s Proposition 65 list of chemicals “known to cause cancer.’ However, these classifications do not distinguish among oil pesticides that may not qualify as carcinogenic due to their degree of refinement. Many such oil pesticides also serve as alternatives to high-toxicity chemicals. For this reason, oil pesticide data was classified separately in this report. Use includes primarily agricultural applications. The grand total for acres treated may be less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation ’s Pesticide Use Reports.

Figure 7: Use trends of pesticides that are oils. Reported pounds of active ingredient (AI) applied include both agricultural and non-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

 

USE TRENDS OF BIOPESTICIDE PESTICIDES

Table 18: The reported pounds of pesticides used that are biopesticides. Biopesticides include microorganisms and naturally occurring compounds, or compounds essentially identical to naturally occurring compounds that are not toxic to the target pest (such as pheromones). Use includes both agricultural and reportable non-agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.

Table 19: The reported cumulative acres treated with pesticides that are biopesticides. Biopesticides include microorganisms and naturally occurring compounds, or compounds essentially identical to naturally occurring compounds that are not toxic to the target pest (such as pheromones). Use includes primarily agricultural applications. The grand total for acres treated may be less than the sum of acres treated for all active ingredients because some products contain more than one active ingredient. Data are from the Department of Pesticide Regulation ’s Pesticide Use Reports.

Figure 8: Use trends of pesticides that are biopesticides. Biopesticides include microorganisms and naturally occurring compounds, or compounds essentially identical to naturally occurring compounds that are not toxic to the target pest (such as pheromones). Reported pounds of active ingredient (AI) applied include both agricultural and non-agricultural applications. The reported cumulative acres treated include primarily agricultural applications. Data are from the Department of Pesticide Regulation’s Pesticide Use Reports.




V. TRENDS IN PESTICIDE USE IN CERTAIN COMMODITIES

This summary describes possible reasons for changes in pesticide use from 2008 to 2009 for the following commodities: almonds, wine grapes, table and raisin grapes, alfalfa, processing tomatoes, cotton, rice, oranges, head lettuce, strawberries, peaches and nectarines, and carrots. These 12 commodities were chosen because each were treated with more than 3 million pounds of active ingredients (AIs) or cumulatively treated on more than 2 million acres, except for head lettuce, which had 1.0 million pounds of AI and 1.7 million acres treated. Collectively, this represents 67 percent of all reported pesticide pounds used (72 percent of all pounds used on agricultural fields) and 69 percent of the acres treated in 2009.

Information used to develop this section was drawn from several publications and phone interviews with pest control advisors, growers, University of California Cooperative Extension farm advisors and specialists, researchers, and commodity association representatives. DPR staff analyzed the information, using their knowledge of pesticides, California agriculture, pests, and pest management practices to draw conclusions about possible explanations for changes in pesticide use. However, it is important to note these explanations are based on anecdotal information, not rigorous statistical analyses.

Reported pesticide use in California in 2009 totaled 156 million pounds, a decrease of 8 million pounds from 2008 (5.0 percent). The AIs with the largest uses by pounds were sulfur, petroleum and mineral oils, metam-sodium, glyphosate, and 1,3-dichloropropene (1,3-D). By pounds, sulfur accounted for 27 percent of all reported pesticide use in 2009. Sulfur use increased 1.6 million pounds (4 percent) from 2008 to 2009 and accounted for most of the increase in pounds of AI. Other non-adjuvant pesticides with the greatest increase in pounds applied include kaolin (856,000-pound increase, 59 percent), pendimethalin (320,000-pound increase, 22 percent), oxyfluorfen (266,000-pound increase, 39 percent), and phosphine (215,000-pound increase, 447 percent). Sulfur is a natural fungicide favored by both conventional and organic farmers and is used mostly to control powdery mildew on grapes and processing tomatoes. Oils are used mostly as insecticides and miticides in orchards; metam-sodium is a fumigant used mostly for carrots, processing tomatoes, and potatoes; glyphosate is an herbicide used mostly for almonds, rights-of-way, and grapes; and 1,3-D is a fumigant used mostly for strawberries, almonds, sweet potatoes, walnuts, and carrots. Kaolin is a fungicide and insecticide used mostly in pomegranates, walnuts, and processing tomatoes; pendimethalin is an herbicide used mostly for alfalfa, almonds, and grapes; oxyfluorfen is an herbicide used mostly for rights-of-way, almonds, and grapes; and phosphine is a fumigant used mostly for regulatory pest control.

In contrast, use of most major pesticides decreased. Use of 1,3-D decreased by 3.5 million pounds (36 percent) even though it was one of the most-used pesticides. Other pesticides with decreases in pounds applied were petroleum and mineral oils (1.7 millio-pound decrease, 6 percent), potassium N -methyldithiocarbamate, also called metam-potassium, (1.4 million-pound increase, 26 percent), copper-based pesticides (947,000-pound decrease, 16 percent), chlorine (693,000-pound decrease, 54 percent), and metam-sodium (665,000-pound decrease, 7 percent). Metam-potassium is a fumigant used mostly for processing tomatoes and carrots; most copper-based pesticides are used as fungicides or algaecides and are used in rice, oranges, and walnuts; and chlorine is a disinfectant. The use of all fumigants decreased 5.4 million pounds (14 percent) in 2009 compared to 2008.

Different pesticides are used at different rates. In California, most pesticides are applied at rates of around 1 to 2 pounds per acre. However, fumigants are usually applied at rates of hundreds of pounds per acre. Thus, comparing use by pounds will emphasize fumigants. Comparing use among different pesticides using acres treated gives a different picture.

Total acres treated with all pesticides in 2009 were 64 million, a decrease from 2008 of 3 million acres (3.9 percent). By acres treated, the non-adjuvant pesticides with the greatest use in 2009 were sulfur, glyphosate, petroleum and mineral oils, copper-based pesticides, and oxyfluorfen. Most of the decrease in total acres treated was from decreases in indoxacarb, methoxyfenoxide, and chlorpyrifos. The AIs with the largest increase in acres treated were pendimeththalin, oxyfluorfen, glufosinate-ammonium, glyphosate, and cyprodinil. Indoxacarb is an insecticide used mostly for alfalfa; methoxyfenoxide is an insecticide used mostly for almonds and grapes; chlorpyrifos is an insecticide used mostly on alfalfa, almonds, and walnuts; and (s)-cypermethrin is an insecticide used mostly on lettuce and alfalfa. Pendimeththalin is an herbicide used mostly for alfalfa, almonds, and grapes; glufosinate-ammonium is an herbicide used mostly in almonds and grapes; and cyprodinil is a fungicide used mostly for almonds and grapes.

DPR data analyses have shown that pesticide use varies from year to year depending upon pest problems, weather, acreage and types of crops planted, economics, and other factors. The winter and spring of 2009 were relatively dry which probably resulted in less weed and disease pressure. Lygus bugs were a problem in some areas for cotton and strawberries because of changing cropping patterns. Also, mites were a problem for some crops because of the dry, hot summer. The reduction in use of fumigants may be due to increased environmental and regulatory concerns.

In the following tables, use is given by pounds of AI applied and by acres treated. Acres treated means the cumulative number of acres treated; the acres treated in each application are summed even when the same field is sprayed more than once in a year. (For example, if the same acre is treated three times in a calendar year with an individual AI, it is counted as three acres treated).

Almonds

Almonds are California’s largest nut crop economically and are the largest crop export from the United States. Based on USDA statistics, the total production of almonds in California in 2009 was about 1.35 billion meat pounds, which was down 17 percent from the crop in 2008. Production decreased because freezing temperatures in March 2009 and mite infestations during the growing season damaged almond orchards. Irrigation water availability was a concern but had minimal impact on the 2009 crop. There are three distinct almond-growing regions in California: the Sacramento Valley, Central San Joaquin Valley and Southern San Joaquin Valley. Weather conditions and pest pressure vary greatly across these regions. Pesticide use may vary regionally in terms of use rates and choices.

Table 20: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for almonds each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, April 2010; marketing year average prices from 2004 to 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, July 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 21: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted, and prices for almonds each year from 2005 to 2009.

In 2009 total pesticide use was 10 million acres treated and 19 million pounds (Table 20). Pounds of AI decreased 4 percent; however, acres treated increased 2 percent compared to 2008. Acres of almonds planted increased 2 percent in 2009 relative to 2008. The combination of decreased pounds and increased planted and treated acreage implies that pesticide use per acre planted and use per acre treated decreased in 2009, both by 6 percent (Table 21). Insecticide use in acres treated decreased 3 percent in 2009 compared to 2008 (Figure 9). Herbicide use in 2009 increased 7 percent and fungicide use increased 2 percent in acres treated when compared to 2008.

Figure 9: Acres of almonds treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 9

The main insecticides in 2009 by acres treated were oils, abamectin, esfenvalerate, pyriproxyfen, and methoxyfenozide. Acres treated with methoxyfenozide, esfenvalerate, and phosmet decreased 40, 19, and 83 percent respectively in 2009 compared to 2008 (Table 22). The use of flubendiamide increased many-fold and the use of oils increased 4 percent. These insecticide data show a shift in the products used for worm control, including navel orangeworm (NOW) and peach twig borer (PTB). Shifts in 2009 were primarily due to the registration of new pesticides, in particular, those containing the new AIs flubendiamide and chlorantraniliprole. Both are in a new reduced-risk insecticide class called anthranilic diamides. Also, new pyrethroid products containing bifenthrin and lambda cyhalothrin were registered. Compared to older-generation pyrethroid products, such as those containing esfenvalerate, these products are more refined, have longer residuals, and are less prone to cause spider mites outbreaks. Because of these new products, the use of traditional worm insecticides such as methoxyfenozide, esfenvalerate, phosmet, and azinphos methyl are expected to decrease.

Table 22: The non-adjuvant pesticides with the largest change in acres treated of almonds from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

The main fungicides by acres treated were iprodione, cyprodinil, boscalid, pyraclostrobin, and propiconazole. The overall use of fungicide did not change much in 2009 compared to 2008. Use of boscalid, pyraclostrobin, pyrimethanil, and copper-based pesticides decreased 38 percent, 38 percent, 64 percent and 22 percent, respectively, in acres treated, while the use of propiconazole and fenbuconazloe increased many-fold in 2009. Because some diseases were becoming resistant to some fungicides, growers tended to switch pesticides and reduce use. Boscalid and pyraclostrobin became ineffective on scab, resulting in decreased use. A dry winter led to less scab and therefore less use of copper-based pesticides in the dormant season. The increased use of propiconazole and fenbuconazole was possibly due to their effectiveness and low cost as bloom fungicides. Fenbuconazole was recently registered for use on almonds.

The main herbicides were glyphosate, oxyfluorfen, glufosinate-ammonium, paraquat dichloride, and pendimethalin. Acres treated with glufosinate-ammonium, oxyfluorfen, and glyphosate increased 32, 10, and 4 percent, respectively, from 2008 to 2009. Glufosinate-ammonium use has increased because of resistance developing to glyphosate. Also, it was reformulated and priced lower in 2007. Oxyfluorfen is often used with glyphosate and as a preemergent for broadleaf weeds. Increase in oxyfluorfen and glyphosate use may be simply due to increased acreage of mature almond trees in the state.

Key arthropod pests in almonds are NOW, San Jose scale (SJS), PTB, web-spinning mites, and ants. Winter sanitation to eliminate mummy nuts has become a standard practice to reduce overwintering NOW larvae. Almonds can be treated with oil alone in the dormant season to control low to moderate populations of SJS. It is likely that other insecticides were added to oil to control higher populations of SJS and PTB. Determining which AIs are being used for what pest is difficult since many AIs can be used for more than one pest. However, treatments in the dormant season and during bloom are usually for PTB, treatments in July and August are mostly for NOW, and treatments in May could be either PTB or NOW (although most May treatments north of Fresno are for PTB and most May treatments south of Fresno are for NOW). Regionally, pesticide use was much less in the Sacramento Valley than the southern San Joaquin Valley. NOW and mite populations are generally higher in the south than in the north.

Wine grapes

In 2009, roughly 63 percent of California vineyards produced wine grapes. There are four major wine grape production regions: North Coast (Lake, Mendocino, Napa, Sonoma, and Solano counties); Central Coast \(Alameda, Monterey, San Luis Obispo, Santa Barbara, San Benito, Santa Cruz, and Santa Clara counties); Northern San Joaquin Valley (San Joaquin, Calaveras, Amador, Sacramento, Merced, Stanislaus, and Yolo \counties); and Southern San Joaquin Valley (Fresno, Kings, Tulare, Kern, and Madera counties). The total pounds of pesticide active ingredients applied to wine grapes increased 3 percent in 2009 compared to 2008 and acres treated increased 8 percent (Table 24).

Factors that influence changes in pesticide use on wine grapes include weather, topography, pest pressures (which vary by region), competition from newer pesticide products, application restrictions, efforts by growers to reduce costs, and increasing emphasis on sustainable farming. The pooled figures in this report may not reflect differences in pesticide use patterns between production regions.

Table 23: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for wine grapes each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, March 2010; marketing year average prices from 2004 to 2007 are from NASS, July 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 24: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted and prices for wine grapes each year from 2005 to 2009.

Figure 10: Acres of wine grapes treated by all AIs in the major types of pesticides from 1994 to 2009. Sulfur accounts for nearly all the fungicide/insecticide category

Figure 10

Table 25: The non-adjuvant pesticides with the largest change in acres treated of wine grapes from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Insecticide use in wine grapes increased significantly in 2009 (Figure 10) pounds applied increased 26 percent, while acres treated increased 24 percent. The major insecticides applied in 2009 by acres treated were oils, imidacloprid, methoxyfenozide, abamectin, buprofezin, and chlorpyrifos. Chlorpyrifos is used before budbreak and after harvest to control mealybugs; imidacloprid is used during warmer weather between budbreak and harvest. Methoxyfenozide is used to control various moths, such as omnivorous leafroller. In 2009, acreage treated with oils increased 4 percent. Oils have many attractive, broad-spectrum properties and are low-risk. Increasingly mixed with fungicides, oils can replace a surfactant and eradicate mildew growth, as well as suppress mites and insects such as grape leafhoppers.

Acres treated with sulfur were unchanged from 2008 (in Figure 10 sulfur accounts for nearly all fungicide/insecticide category), while acres treated with all other fungicides increased 5. Sulfur, copper-based pesticides, trifloxystrobin, quinoxyfen, and tebuconazole were the most-used fungicides in terms of acres treated. Acres treated with lime sulfur in early 2009 overwintering disease inoculum were unchanged from 2008. Dormant season disease pressure was low in 2009 due to low rainfall. Copper-based pesticides, used to treat downy mildew and botrytis bunch rot, were applied to 14 percent fewer acres in 2009 compared to 2008 (Table 25).

The acres treated with herbicides increased 20 percent in 2009 compared to 2008. In terms of acres treated, herbicides used most in wine grapes were glyphosate, oxyfluorfen, glufosinat-ammonium, paraquat, flumioxazin, and simazine. The acres treated with simazine, paraquat, flumioxazin, and glufosinate-ammonium increased 23, 53, 47, and 9 percent respectively. Acreage treated with rimsulfuron increased 151 percent. This is likely due to the increased prevalence of glyphosate-resistant weeds, such as marestail and fleabane, in vineyards. Both glufosinate-ammonium and rimsulfuron are used specifically to control these weed species.

Acres treated with plant growth regulators (PGR) increased 39 percent in 2009 compared to 2008, though the total number of acres treated was small. The most common PGRs were gibberellins, which are applied in early spring in order to lengthen and loosen grape clusters. Less compact clusters may be less vulnerable to berry splitting and bunch rot.

Table and Raisin Grapes

Table and raisin grapes comprised approximately 37 percent of California’s total grape crop in 2009, the rest being wine grapes. These categories shift depending on market conditions, since some grape varieties can be used for more than one purpose. Thompson Seedless is the leading raisin grape variety, while Flame Seedless is the leading table grape variety. California produced about 2.1 million tons of raisin grapes and 850,000 tons of table grapes in 2009. Statewide table grape and raisin tonnage decreased 13 percent and 16 percent, respectively, relative to 2008 production. Total bearing acreage of table and raisin grapes was unchanged. The decrease in production was due to a combination of drought, extreme hot weather, and flare-ups of powdery mildew.

Table 26: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for table and raisin grapes each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, March 2010; marketing year average prices from 2004 to 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, July 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 27: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted, and prices for table and raisin grapes each year from 2005 to 2009.

The major insecticides applied in 2009 by acres treated were oils, imidacloprid, methoxyfenozide, cryolite, Bacillus thuringiensis, and buprofezin. The acres treated with insecticides increased 6 percent from 2008 (Figure 11). Imidacloprid and buprofezin are used during warm weather between budbreak and harvest to control mealybug infestations. Cryolite is an insect stomach poison applied early in the season to control lepidopterous pests, such as omnivorous leafroller. Methoxyfenozide controls similar pests, but can be used later in the growing season than cryolite.

Acres treated with sulfur decreased 2 percent (in Figure 11 sulfur accounts for nearly all the fungicide/insecticide category), while acres treated with all other fungicides decreased 3 percent. Sulfur, copper-based pesticides, myclobutanil, trifloxystrobin, tebuconazole, boscalid, and pryaclostrobin were the most used fungicides in terms of acres treated. Acres treated with lime sulfur in early 2009 against overwintering disease inoculum increased 62 percent. Dormant season disease pressure was low due to low rainfall. Copper-based pesticides, used to treat downy mildew and botrytis bunch rot, were applied to 10 percent fewer acres compared to 2008 (Table 28).

The acres treated with herbicides decreased 9 percent in 2009 compared to 2008 (Figure 11). Herbicides used most in table and raisin grapes by acres treated were glyphosate products, glufosinate-ammonium, paraquat, oxyfluorfen, simazine, and pendimethalin. The acres treated with glyphosate, paraquat, and oxyfluorfen decreased 10, 12, and 16 percent respectively. In contrast, glufosinate-ammonium and rimsulfuron-treated acreage increased 10 and 66 percent respectively, while pendimethalin-treated acreage increased 311 percent. Increased use of glufosinate-ammonium and rimsulfuron is likely due to the increased prevalence of glyphosate-resistant weeds, such as marestail and fleabane, in vineyards. Both of these herbicides are used specifically to control these weed species. It is likely that pendimethalin is being used as a cheaper alternative to oryzalin.

Figure 11: Acres of table and raisin grapes treated by all AIs in the major types of pesticides from 1994 to 2009. Sulfur accounts for nearly all the fungicide/insecticide category.

Figure 11

Acres treated with plant growth regulators (PGRs) increased less than 1 percent in 2009 compared to 2008. The most commonly used PGRs were gibberellins, which are applied in early spring to lengthen and loosen grape clusters. Less compact clusters may be less vulnerable to berry splitting and bunch rot. Gibberellin-treated acres increased 1 percent in 2009.

Table 28: The non-adjuvant pesticides with the largest change in acres treated of table and raisin grapes from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Alfalfa

Alfalfa hay is produced for animal feed in California. Most counties produce some alfalfa hay but more than half of the state’s production comes from Fresno, Kern, Imperial, Merced, and Tulare counties. Harvested alfalfa acres increased 3 percent in 2009 compared to 2008 but the price per ton decreased 47 percent. The dairy industry remains the biggest market for alfalfa hay in California. The decreased price for hay was due to weak economic conditions, downturn in the dairy industry, and increased supplies from other western states that usually ship large quantities of hay into California to augment local production. The total pounds of pesticide active ingredients applied to alfalfa increased 3 percent in 2009 relative to 2008; however, the acres treated with pesticides decreased 20 percent (Table 29).

Statewide, insecticide use on alfalfa increased 4 percent in pounds of AI whereas the acres treated decreased 28 percent in 2009 compared to 2008 (Figure 12). The decrease in acres treated with insecticides were mainly from reduced uses of cyfluthrin (83 percent reduction), methxyfenozide (71 percent reduction), s-cypermethrin (57 percent reduction), indoxacarb (55 percent reduction), chlorpyrifos (22 percent reduction), and methomyl (51 percent reduction) (Table 31). In contrast, the acres treated with naled and beta-cyfluthrin increased 37 and 6 percent, respectively, in 2009 compared to 2008. In 2009, growers switched to AIs such as sulfur that do not have significant adverse environmental impacts. Sulfur is used at high rates per acre, which partly explains why total pounds of AI increased even though total acres treated decreased. The uncertainty surrounding hay prices, water availability, and the downturn in the dairy industry affected management practices in 2009. The new management practices resulted in changes in both insect pest populations and insecticide use.

Table 29: Total reported pounds of all active ingredients (AI), acres treated, acres harvested, and prices for alfalfa each year from 2005 to 2009. Harvested acres from 2004 to 2008 are from CDFA, 2009; harvested acres in 2009 are from NASS, June 2010; marketing year average prices in 2004 are from NASS, July 2005; marketing year average prices from 2005 to 2006 are from NASS, July 2007; marketing year average prices in 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, February 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 30: Percent difference from previous year for reported pounds of all AIs, acres treated, acres harvested, and prices for alfalfa each year from 2005 to 2009.

Decrease in the use of indoxacarb, methoxyfenozide, and s-cypermethrin was mainly in the San Joaquin, Sacramento and Imperial valleys. Decreased use of lambda-cyhalothrin was mainly in the San Joaquin and Imperial valleys. The decrease in chlorpyrifos use was predominantly in the San Joaquin Valley while methomyl use decreased mainly in San Joaquin and Imperial valleys. The statewide increase in insecticide use in pounds was due to insect pressure. This was especially true for western yellow striped armyworm, beet armyworm, alfalfa caterpillar, and Egyptian alfalfa weevil. Also, as the price of hay decreased, growers let the hay grow longer and sprayed less frequently but more intensely for insect pests to avoid insect damage.

Figure 12: Acres of alfalfa treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 12

Statewide herbicide use in pounds and acres treated were relatively stable, marginally decreasing 2 and 1 percent respectively, in 2009 compared to 2008 (Figure 12). Use of most of the top 10 high-use herbicides decreased in 2009, except for pendimethalin, paraquat dichloride, and hexazinone. Use of paraquat dichloride increased, possibly because it is applied as an alternative to diquat dibromide, a desiccant used in seed production. Seed growers desiccate seed fields prior to harvest. The increase in pendimethalin use may be associated with the halt in planting of Roundup Ready alfalfa. Growers returned to the use of pre-plant herbicides such as pendimethalin and 2,4-DB. Decreased use of glyphosate may also be due to issues with Roundup Ready alfalfa. The decrease in herbicide use in 2009 occurred mainly in the Sacramento and San Joaquin Valleys whereas most of the increased applications occurred in the Imperial Valley. Although the reasons for selecting certain herbicides over others were unclear, efforts to use materials that are less likely to contaminate groundwater may have played a role in the general pattern in herbicide use.

Fungicide use for alfalfa is minimal and is not as significant as it is for insecticides and herbicides.

Table 31: The non- adjuvant pesticides with the largest change in acres treated of alfalfa from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Processing tomatoes

Processing tomato growers planted 312,000 acres in 2009, a 10 percent increase from 2008. Total tons of processing tomato production in 2009 increased 26 percent from 2008. The highest concentration of processing tomato acreage continues to be in the southern San Joaquin Valley. Fresno County leads the state in production with 35 percent (108,000 acres) of the statewide acres, followed by San Joaquin County (39,000 acres), Yolo County (38,000 acres), and Kings County (29,000 acres).

Pesticide use, in terms of pounds of active ingredients (AI), increased 26 percent, from 12 million pounds in 2008 to 15 million pounds in 2009 (Table 32). Sulfur, metam-sodium, and metam-potassium accounted for 86 percent of the total pounds of pesticide AI applied to processing tomatoes in 2009. Non-adjuvant pesticides used most in 2009, as measured by acres treated, were sulfur, trifluralin, s-metolachlor, chlorothalonil, pyraclostrobin, and glyphosate, all of which saw an increase in acres treated. The most-used pesticide category for processing tomatoes, as measured by acres treated, was insecticides, which increased 10 percent from 2008 to 2009 (Figure 13). In terms of pounds of AI applied, fungicide/insecticide (which is nearly all sulfur and kaolin) was the pesticide type most-used and saw a 34 percent increase in pounds of AI applied. The price of processing tomatoes increased 10 percent in 2009 compared to 2008.

Table 32: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for processing tomatoes each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, January 2010; marketing year average prices from 2004 to 2005 are from NASS, January 2007; marketing year average prices in 2006 are from NASS, January 2009; marketing year average prices from 2007 to 2009 are from NASS, January 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 33: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted, and prices for processing tomatoes each year from 2005 to 2009.

Fungicide use, in terms of acres treated, increased 71 percent, which was the largest percent increase for the pesticide types. The most-used fungicides were sulfur, chlorothalonil, pyraclostrobin, myclobutanil, azoxystrobin, copper-based pesticides, mefenoxam, and difenoconazole. The use of all these fungicides increased. The increases in fungicide uses were attributable to the onset of severe tomato powdery mildew, one of the major issues for processing tomato growers. In 2009, there was an extremely large processing tomato crop which took longer than usual to harvest; this may have factored into the increased fungicide use. Sulfur, myclobutanil, and azoxystrobin are applied for mildews. Sulfur use increased 42 percent, myclobutanil 26 percent, and azoxystrobin 144 percent (Table 34). Dimethomorph, also used on powdery mildew, increased dramatically from the previous year, from 384 acres treated in 2008 to 9,164 acres in 2009. Difenoconazole, an AI newly registered for use on tomatoes, was used on 20,401 acres in 2009, primarily to combat powdery mildew. Use of copper-based pesticides increased 163 percent, likely due to the presence of bacterial speck, another major pest in the spring. Late blight is controlled using mefenoxam, pyroclostrobin, as well as azoxystrobin. Mefonoxam use increased 42 percent and pyroclostrobin 38 percent. Chlorothalonil use increased 73 percent in 2009 from 2008. A possible reason for the overall increase in fungicides may be due to increased knowledge of fungal pests and their economic effects, resulting in a higher number of prophylactic treatments.

Figure 13: Acres of processing tomatoes treated by all AIs in the major types of pesticides from 1994 to 2009. Sulfur and kaolin accounts for nearly all the fungicide/insecticide category.

Figure 13

Herbicide use increased 20 percent, in terms of acres treated, from 2008 to 2009 (Figure 13). The main herbicides used in processing tomato production were trifluralin, s-metolachlor, glyphosate, and rimsulfuron. Primary weeds of concern for processing tomatoes are nightshades and bindweed. Acres treated with trifluralin and s-metolachlor increased 9 percent and 13 percent, respectively. However, acres treated with rimsulfuron decreased 6 percent. The use of glyphosate, commonly used for pre-plant treatments in late winter and early spring, increased 42 percent. Use of carfentrazone-ethyl and clethodim increased significantly from 2008 to 2009: 6,610 to 19,151 acres for carfentrazone-ethyl and 4,718 to 12,691 acres for clethodim.

In 2009, 840,000 acres were treated with insecticides. Recurrent arthropod pests in processing tomatoes are russet mites, tomato fruitworms, armyworms, and potato aphid. Dimethoate, imidacloprid, chlorantraniliprole, lambda-cyhalothrin, carbaryl, bifenthrin, and methoxyfenozide were the most- used insecticides in 2009. Dimethoate, used for aphid control, remained the most-used insecticide in pounds of AI and acres treated in 2009; use did not change from 2008 to 2009. Due to an increase in the incidence of tomato spotted wilt, which is vectored by western flower thrips, there was a 25 percent increase in acres treated with imidacloprid for thrips management (Table 34). The application of lambda -cyhalothrin, also used to control thrips, increased 17 percent in acres treated. Bifenthrin use, which increased 72 percent in acres treated, although pounds of AI decreased 2 percent, is also used to manage tomato spotted wilt, as well as mites and stinkbugs. The use of chlorantraniliprole, a new AI used to control lepidopterous pests, increased 99 percent. Carbaryl use increased 63 percent. The increased use of carbaryl is likely due to the appearance of ground beetles during transplanting and seedling emergence. Methoxyfenozide saw a 43 percent decrease in 2009 from the previous year. Although not one of the most highly used insecticides, azadirachtin had the largest percentage increase in use. Use of malathion decreased dramatically for 6,443 acres treated in 2008 to 45 acres in 2009, likely due to increased regulatory concerns.

Table 34: The non-adjuvant pesticides with the largest change in acres treated of processing tomatoes from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Processing tomato growers use the fumigants potassium N-methyldithiocarbamate (metam-potassium), metam-sodium, 1,3-dichloropropene (1,3-D), and to a lesser extent, aluminum phosphide. The three main fumigants are used to manage root-knot nematodes and for weed control, particularly those of the nightshade family. In 2009, fumigant use in pounds increased 9 percent from 2008 and accounted for about 24 percent of the total pounds of pesticide AIs applied. However, acres treated with fumigants decreased 15 percent. The number of acres treated with metam-potassium and 1,3-D decreased 26 and 62 percent, respectively, which may have been due to the availability of many varieties of tomato with resistance to several species of root knot nematode. Metam-sodium use increased 13 percent. Aluminum phosphide use was up 110 percent, a significant increase that may have been due to increased rodent control to protect buried drip tape.

Cotton

Cotton is grown for fiber, oil, and animal feed. Once one of the most widely grown crops in California, acres have decreased dramatically in the last few years. Total cotton acreage decreased 31 percent from 2008 to 2009. Two main kinds of cotton are grown: upland and Pima. In the last several years, the percent of cotton acres in Pima has increased; in 2009, 63 percent of cotton acreage was in Pima. Some upland cotton has also been genetically modified to be tolerant to the herbicide glyphosate. Most cotton is grown in the southern San Joaquin Valley, but a small percentage is grown in Imperial and Riverside counties and a few counties in the Sacramento Valley.

Table 35: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for cotton each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, June 2010; marketing year average prices in 2004 are from NASS, July 2005; marketing year average prices from 2005 to 2006 are from NASS, July 2007; marketing year average prices in 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, February 2010. "RR" refers to Roundup-Ready cotton. Acres treated means cumulative acres treated (see explanation p. 8).

Table 36: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted, and prices for cotton each year from 2005 to 2009.

Figure 14: Acres of cotton treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 14

Total pesticide use on cotton decreased 40 percent from 2008 to 2009 (Table 35); use per acre planted also decreased. Use in all counties decreased, except in Sutter County, which has only small cotton acreage. Use of all AI types decreased; however, herbicides and fungicide had much smaller decreases (Figure 14). The use of insecticides decreased 54 percent in acres treated and 52 percent in pounds; herbicide use decreased 15 percent in acres treated and 9 percent in pounds; harvest aids, which are chemicals used to defoliate or desiccate cotton plants before harvest, decreased 44 percent in acres treated and 42 percent by pounds of AI; and fungicide use decreased 9 percent in acres treated and 6 percent in pounds.

Insecticide use decreased in 2009, partly because of reduced acreage, but use per acre planted decreased as well. The most-used insecticides by acres treated in 2009 were flonicamid, abamectin, acetamiprid, imidacloprid, chlorpyrifos, bifenthrin, and indoxacarb. Most insecticides decreased 40 to 80 percent in pounds, but use in pounds of bifenthrin increased 190 percent, thiamethoxam increased 34 percent, and buprofezin increased 9 percent. Although use of acetamiprid decreased, use per acres planted increased. By acres treated, nearly all insecticide use decreased. Acres treated with bifenthrin decreased 53 percent and thiamethoxam decreased 42 percent. Pounds of bifenthrin increased and acres treated decreased because of the use of a fairly new bifenthrin-containing product that can be used at higher rates. Insecticide use decreased in all major counties. The increase in pounds and rate of use of bifenthrin occurred primarily in a southwestern area of the San Joaquin Valley in June and July. Also increasing by pounds in this area were acetamiprid, buprofezin, thiamethoxam, malathion, pyriproxyfen, and Bacillus thuringiensis.

Table 37: The non-adjuvant pesticides with the largest change in acres treated of cotton from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

In 2009, most fields had low to moderate pest pressure, which is reflected in the decrease in insecticide use. Lygus bugs were generally not as big a problem in 2009 as in 2008, but in the previous few years they had been a problem in some areas because of greater acreage of safflower, less irrigation of alfalfa, and fewer acres of cotton. Safflower acreage increased especially in southern San Joaquin Valley, which accounts for the increased insecticide use in that area. Both safflower and alfalfa are good hosts for lygus and provided a continuous source of the bugs, which move into nearby cotton fields when safflower and alfalfa mature. Bifenthrin, whose rate of use increased, and flonicamid, the most-used insecticide, are used mostly for lygus. Acetamiprid use increased in some areas probably because of localized outbreaks of cotton aphid. Buprofezin is an insect growth regulator used for whiteflies.

The most-used herbicides by acres treated in 2009 were glyphosate, pendimethalin, paraquat dichloride, oxyfluorfen, trifluralin, and pyraflufen-ethyl. Use of most herbicides decreased by pounds and acres treated 1 to 60 percent except the use of paraquat dichloride, which increased 38 percent in pounds, MSMA, which increased 73 percent, and pyraflufen-ethyl, which increased 35 percent. Herbicide use decreased in all counties except in the southern area of the San Joaquin Valley, where most of the increase was from glyphosate use, and most of that increase occurred in May. Some AIs, such as paraquat dichloride, are used both as harvest aids and herbicides. Here it is assumed if use occurred between August and November it was used as a harvest aid, otherwise as an herbicide. The decrease in herbicide use was due mostly to the decrease in acres planted. The increased use of glyphosate in some areas was probably due to increased plantings of Roundup-Ready cotton, which is genetically engineered to be resistant to the glyphosate.

The main harvest aids by acres treated in 2009 were thidiazuron, diuron, ethephon, pyraflufen-ethyl, urea dihydrogen sulfate, and mepiquat chloride. Although mepiquat chloride is included here among the harvest aids, it is actually a growth regulator and is typically used mid-season. Use of all harvest aid AIs decreased 35 to 50 percent in all counties, attributable mostly to the decrease in acres planted.

Fungicides are not widely used in cotton, but their use per acre planted has been increasing in most years between 2002 and 2009 because of increased problems with seedling diseases, mostly Rhizoctonia. The most-used fungicides were azoxystrobin and iprodione; although their use decreased by pounds and acres treated, the use per acre planted increased. Other fungicides used were TCMTB, myclobutanil, chloroneb, mefenoxam, pyraclostrobin, and fludioxonil; use of all of these fungicides increased. Azoxystrobin and iprodione are applied to cotton fields at planting in March and April to control seedling diseases. The other fungicides are used as seed treatments and are not applied to the field.

Rice

California’s Sacramento Valley has more than 95 percent of the state’s rice acreage. The remainder is grown in the northern and central San Joaquin Valley. The leading rice-producing counties are Colusa, Sutter, Butte, Glenn, and Yolo. Approximately 500,000 acres in the Sacramento Valley are of a soil type restricting the crops to rice or pasture. The remainder of the acreage has greater crop flexibility.

Pesticide use decreased both in pounds of active ingredients applied and acres treated, by 3 percent and 2 percent, respectively, from 2008 to 2009 (Table 39). Planted acres increased 8 percent. There were no major shifts in pest pressure in 2009. As in 2008, herbicides were the most-used pesticide in 2009 (Figure 15). They accounted for 73 percent of non-adjuvant pesticide acres treated and 62 percent of the total pounds of non-adjuvant active ingredients applied. Herbicide, insecticide, and algaecide non-adjuvant pesticide acres treated decreased 5, 14, and 8 percent, respectively, from 2008 to 2009, while use of fungicide increased 15 percent. Major pesticides with the largest percent increases in acres treated included the fungicides propiconazole and trifloxystrobin and the herbicides bensulfuron methyl, 2,4-D, and bispyribac sodium. Pesticides with the largest percentage decreases in acres treated included the herbicides fenoxaprop-ethyl, cyhalofop butyl, and clomazone, the insecticide lambda- cyhalothrin, and the algaecide copper sulfate (Table 40).

Table 38: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for rice each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, June 2010; marketing year average prices in 2004 are from NASS, July 2005; marketing year average prices from 2005 to 2006 are from NASS, July 2007; marketing year average prices in 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, February 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 39: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted, and prices for rice each year from 2005 to 2009.

Lambda-cyhalothrin remained the most widely used insecticide by acres treated, although its use decreased 16 percent in 2009 from 2008. (S)-cypermethrin, the other commonly used insecticide, was also used less in 2009, its use decreasing 5 percent. Both insecticides are used primarily for rice water weevil control and secondarily for armyworm and tadpole shrimp. The rice water weevil is the number one insect pest in California rice. Insect pressure is low for California rice these insecticides are used on only about 10 percent of planted fields. Copper sulfate is also used to control tadpole shrimp; however its primary use is for algae control in rice fields. Copper sulfate is known to bind to organic matter such as straw residue, making it less effective. Copper sulfate use decreased 8 percent from 2008 to 2009. Growers often rely on pyrethroids (e.g., lambda-cyhalothrin) to control tadpole shrimp and rice water weevil soon after flooding.

Trifloxystrobin, propiconazole, and azoxystrobin are reduced-risk fungicides often used as preventative treatments. Use of all three fungicides increased in treated acreage, largely in response to occurrences of rice blast. The higher disease pressure in 2009 may be a result of) resistance to the currently registered strobilurin fungicides, the phase-down of rice-straw burning (which simultaneously acted as a disease control, and cooler temperatures.

Figure 15: Acres of rice treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 15

The major herbicides used on rice in 2009 in terms of acres treated were propanil, triclopyr (triethylamine salt), clomazone, bispyribac-sodium, cyhalofop-butyl, penoxsulam, thiobencarb, bensulfuron methyl, 2,4-D, and fenoxaprop-ethyl. Use of all decreased between 2008 and 2009 except bensulfuron methyl, 2,4-D, bispyribac-sodium and thiobencarb, which increased 148, 110, 19 and 8 percent, respectively. The large increase in bensulfuron methyl use was somewhat surprising, given that widespread resistance to this herbicide is present in the fields. It is thought that price, difficulties in controlling ricefield bulrush with other products, marketing, and relative safety could be responsible for the increase in bensulfuron methyl use. Resistance is also an issue for clomazone, which saw a 20 percent decrease from 2008 to 2009.

Table 40: The non-adjuvant pesticides with the largest change in acres treated of rice from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Oranges

California accounts for 26 percent of the citrus production in the United States. Oranges on average account for about two-thirds of California’s citrus crop (USDA Economic Research Service, 2007). Eighty-six percent of California oranges are grown in the San Joaquin Valley (Fresno, Kern and Tulare counties); the rest are grown in the interior region (Riverside and San Bernardino counties) and on the south coast (Ventura and San Diego counties). The number of bearing acres declined slightly (1 percent) in 2009 from 2008 (Table 42). Orange production was 22 percent lower in 2009 compared to 2008, boosting the price per box 31 percent.

The drought conditions in California affected fruit and nut tree production in the San Joaquin Valley, the state’s major orange production region. There have already been reports of damage to navel oranges due to insufficient water. Continued drought conditions could stress the trees and may potentially have an adverse effect on next season’s production.

Table 41: Total reported pounds of all active ingredients (AI), acres treated, acres bearing, and prices for oranges each year from 2005 to 2009. Bearing acres from 2004 to 2008 are from CDFA, 2009; bearing acres in 2009 are from NASS, September 2009; marketing year average prices from 2004 to 2005 are from NASS, July 2006; marketing year average prices from 2006 to 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, September 2009. Acres treated means cumulative acres treated (see explanation p. 8).

Table 42: Percent difference from previous year for reported pounds of all AIs, acres treated, acres bearing, and prices for oranges each year from 2005 to 2009.

Total pounds of pesticides used decreased 10 percent from 2008 to 2009 (947,359 pounds) and acres treated decreased 4 percent (81,566 acres). Pounds of pesticide used and acres treated have steadily fallen since 2005.

Overall, pounds of insecticides used in 2009 decreased 11 percent relative to 2008. In contrast, acres treated with insecticides increased 4 percent. The majority of the decrease in pounds came from reductions in the use of dimethoate, chlorpyrifos, and oil.

Oil, chlorpyrifos, cryolite, dimethoate, carbaryl, and Bacillus thuringiensis were the most-used insecticides based on pounds of active ingredients applied, but the amount used of each decreased from 2008. Pounds used of dimethoate decreased 40 percent, chlorpyrifos decreased 12 percent, and horticulture oil decreased 9 percent. Oil is a broad spectrum pesticide that kills soft-bodied insects such as aphids, immature whiteflies, immature scales, psyllids, immature true bugs, thrips, and some insect eggs as well as mites. Oils also control powdery mildew and other fungi. Oils are also added to other pesticides as adjuvants. Chlorpyriphos is a broad-spectrum insecticide used primarily for citricola scale control, but resistance has been documented. Growers are shifting to other insecticides such as imidacloprid. Dimethoate is used to treat citrus thrips, and its use is declining as it is being replaced by spinosad and spinetoram.

Figure 16: Acres of oranges treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 16

Oil, spinosad, pyriproxyfen, beta-cyfluthrin, abamectin, and chlorpyrifos were the insecticides used the most by acres treated. Pyriproxyfen is used for California red scale control and its acres treated increased 23 percent in 2009. The use of oil by acres treated, decreased marginally (1 percent decrease) in 2009 compared to 2008. Spinosad and spinetoram are primarily used to treat citrus thrips and their uses are increasing as growers replace dimethoate and formetanate. Acres treated with spinosad increased 27 percent; spinetoram was first used in 2008 and its use increased 77 percent to 24,931 acres in 2009. Growers are shifting to spinetoram because it is more persistent than spinosad. The use of hexythiazox to treat mites and spirotetramat to control California red scale increased 130 percent and 238 percent, respectively. These newly registered insecticides are very selective, allowing natural enemies to survive. They may eventually replace older insecticides and miticides.

Acres treated with fungicides decreased 10 percent between 2008 and 2009 and the pounds applied decreased 16 percent. The decrease was primarily due to reductions in use of copper-based pesticides, 12 percent decrease by acres treated and 16 percent decrease in terms of pounds AI applied. Copper- based pesticides are the most widely used fungicide on oranges. It is used to prevent Phytophthora gummosis, Phytophthora root rot, and fruit diseases such as brown rot and Septoria spot. These diseases are exacerbated by wet, cool weather during harvest. The 2009 winter and spring were dry, and fungal diseases were not as severe as in normal rainfall years. Similarly, imazalil is used as a post-harvest treatment to control storage decay and its use in pounds was reduced 40 percent in 2009 from 2008.

Table 43: The non-adjuvant pesticides with the largest change in acres treated of oranges from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Acres treated with herbicides decreased 43,635 acres (8 percent) between 2008 and 2009. The pounds of herbicides used decreased only 1 percent. Glyphosate, a post-emergent herbicide, was the most-used herbicide, followed by simazine and diuron, both pre-emergent herbicides. The pounds of glysophate applied in 2009 compared to 2008 increased 12 percent. In terms of pounds applied, use of simazine increased 1 percent in 2009, while diuron decreased 8 percent. Pendimethalin use in pounds decreased 45 percent and acres treated decreased 43 percent. The acres treated with rimsulfuron increased 58 percent. The increase in acres treated is most likely due to growers trying new products in lieu of some older herbicides. Decreased use of herbicides is partially due to ground water regulations, particularly those that affect the use of simazine and diuron, which are classified as ground water contaminates and regulated accordingly. Paraquat dichloride is associated with acute inhalation toxicity and worker safety issues. In addition, the dry weather in 2009 reduced weed pressure so fewer herbicides were needed.

Head Lettuce

Head lettuce is grown in four areas in the state: the central coastal area (Monterey, San Benito, Santa Cruz, and Santa Clara counties); the southern coastal area (Santa Barbara and San Luis Obispo counties); the San Joaquin Valley (Fresno, Kings, and Kern counties); and the southern deserts (Imperial and Riverside counties). In 2004, 59 percent of all California head lettuce was planted in the central coastal area, 17 percent in the southern coastal area, 12 percent in the San Joaquin Valley, and 11 percent in the southern deserts. In 2009, California produced about 85 percent of the head lettuce grown in the United States.

Table 44: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for head lettuce each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, January 2010; marketing year average prices from 2004 to 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, January 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 45: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted, and prices for head lettuce each year from 2005 to 2009.

Pesticide use on head lettuce fluctuated from 2005 through 2009 (Table 44). Use of all classes of pesticide declined from 2008 to 2009 (Figure 17). There was a 1 percent decrease in acres of head lettuce planted from 2008 to 2009 and a 2 percent decrease in acres of head lettuce harvested, yet yield per acre increased 4 percent, and overall production rose 2 percent.

The major pesticides with the largest increase in acres treated were the insecticide spirotetramat and the fungicides mandipropamid, fenamidone, and dimethomorph (Table 46). Major insecticides with the largest decrease were flonicamid, cyfluthrin, indoxacarb, diazinon, acetamiprid, permethrin, oxydemeton methyl, methoxyfenozide, (s)-cypermethrin, acephate, and imidacloprid. During 2009, the top insecticides used (by acres treated) were lambda cyhalothrin, imidacloprid, permethrin, (S)-cypermethrin, and spirotetramat. The main fungicides used were maneb, dimethomorph, propamocarb hydrochloride, boscalid, and mandipropamid. Three herbicides dominated: propyzamide (pronamide), bensulide, and benefin. Metam- sodium was the only fumigant used in the San Joaquin Valley; methyl bromide and chloropicrin were used only in the central coastal area.

Figure 17: Acres of head lettuce treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 17

Insecticide use steadily declined from 2005 to 2009. Use from 2008 to 2009, as measured by acres treated, varied from 30 percent less in the San Joaquin Valley to 4 percent less in the southern coastal area. Use of lambda cyhalothrin, mostly for symphylans, increased in the central coast and San Joaquin Valley. Use of the neonicotinoid insecticide imidacloprid, used mostly to suppress lettuce and foxglove aphids, fell about 20 percent in all areas except the San Joaquin Valley, where use increased 9 percent. In the southern deserts, permethrin is mostly used for managing seedling pests such as crickets, earwigs, cutworms, and sowbugs. Its use decreased in that area 25 percent. Permethrin use also decreased in the inland areas, but increased in the coastal areas, where it is used for loopers and other lepidopterous pests. The insecticide (S)-cypermethrin is used to manage caterpillars of beet armyworm and cabbage looper, primarily pests in the southern deserts. During 2009, statewide use of (S)-cypermethrin decreased 18 percent, but its use in the southern coastal area increased 72 percent. From 2008 to 2009, use of the aphid systemic insecticide acephate declined in all regions except the southern deserts.

Use of all of the aphid insecticides-diazinon, oxydemeton-methyl, acetamiprid, imidacloprid, an flonicamid-fell off from 2008 to 2009, except use of spirotetramat, which increased almost threefold in all areas except the San Joaquin Valley, where use increased almost twofold. Use of acetamiprid increased in the southern deserts. Use of insecticides that target Lepidoptera generally decreased in all areas.

Table 46: The non-adjuvant pesticides with the largest change in acres treated of head lettuce 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Fungicide use by acres treated increased 1 percent throughout California from 2008 to 2009, although use by pounds decreased 11 percent. Use by acres treated decreased in the southern deserts, San Joaquin Valley, and central coast (31, 3, and 1 percent, respectively), but cooler-than-normal spring weather and late spring rains throughout California may have led to a 20 percent increase in fungicide use in the southern coastal area, especially the Santa Maria Valley. In the central coastal area, growers are using more drip irrigation, which usually reduces the incidence of downy mildew and lettuce drop, requiring less use of fungicides.

Several active ingredients–some containing conventional AIs and some containing reduced risk AIs –are rotated to control downy mildew, a disease that has many pathovars. Maneb, used primarily to manage downy mildew and prevent anthracnose, was again the dominant fungicide, as it has been every year since the early 1990s. Statewide use of maneb declined from 2008 to 2009, although use in the southern coast remained constant. Use of dimethomorph and fosetyl-al increased in the coastal areas and declined in inland areas. A new product containing mandipropamid was registered in June 2008 and was the third most used fungicide by acres in the coastal areas to manage downy mildew. Use of fenamidone shot up in the Central Coast and was the second most used fungicide in the San Joaquin Valley. Use of propamocarb hydrochloride for seedling diseases increased in the southern coast and decreased in the southern deserts and central coast.

Lettuce drop (Sclerotinia drop) is another fungal disease controlled with a changing array of AIs. Use of iprodione had declined in all areas from 2004 to 2009. Use of boscalid, a reduced-risk material, continued to rise in all lettuce-growing regions except the Central Coast. Sulfur is applied as a foliar treatment for powdery mildew and is mostly used in the San Joaquin Valley, where its use decreased 22 percent from 2008 to 2009.

Herbicide use by acres treated decreased statewide 15 percent from 2008 to 2009, most notably in the inland areas. Use of propyzamide (pronamide), applied as a postplant-preemergence herbicide, decreased statewide 14 percent from 2008 to 2009. Consistent with its use for the past ten years, propyzamide was applied to many more acres than the pre-emergent herbicide, bensulide, which targets small-seeded annual grasses and is not as effective as propyzamide in the coastal areas. Use of benefin, a preplant herbicide popular in the San Joaquin Valley, decreased from 2008 to 2009 in all areas and was not used at all in the southern coastal area.

Nematodes are not economic pests of head lettuce so soil is fumigated primarily to manage soil-borne diseases and suppress weeds. In the central coastal area, growers often rotate lettuce with strawberries, for which fumigation is routine. In 2009, 20 percent of total pounds of AI applied were fumigants; however, they were used on 1 percent of all planted lettuce acreage. No fumigants were used in the southern deserts or southern coastal area. Metam-sodium, a broad-spectrum contact soil sterilant, was used only in the San Joaquin Valley, where its use from 2008 to 2009 dropped 60 percent. Use of metam-potassium plummeted to zero. Methyl bromide and chloropicrin, typically used only in the central coastal area, were not used in 2008. In 2009, these fumigants were applied to around 0.1 percent of central coast acres planted to lettuce.

Strawberries

California produces 89 percent of the total U.S. production of 2.8 billion pounds of strawberries. In 2009, California produced 2.49 billion pounds valued at more than $1.72 billion. Strawberries are grown mostly for fresh market ($1.58 billion). Market prices determine the amount processed. California strawberry production occurs primarily along the central and southern coast, with smaller but significant production in the Central Valley.

Strawberry acres harvested increased 6 percent and acres treated with pesticides increased 9 percent from 2008 to 2009 (Table 48). Total pounds of pesticide applied changed insignificantly from 2008 to 2009. Fungicides, followed by insecticides, account for the largest proportion of pesticides applied by acres treated (Figure 18). By acres, use of fungicides increased 8 percent, while insecticides increased 18 percent and herbicides increased 94 percent. The major pesticides with greatest increase in acres treated from 2008 to 2009 were malathion, novaluron, naled, oil, sulfur, quinoxyfen, myclobutanil, and captan (Table 49). The major pesticides with decreased use by acres treated were boscalid, pyraclostrobin, spinosad, spinetoram, and methomyl.

Table 47: Total reported pounds of all active ingredients (AI), acres treated, acres harvested, and prices for strawberries each year from 2005 to 2009. Harvested acres from 2004 to 2008 are from CDFA, 2009; harvested acres in 2009 are from NASS, July 2010; marketing year average prices from 2004 to 2006 are from NASS, August 2009; marketing year average prices from 2007 to 2009 are from NASS, July 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 48: Percent difference from previous year for reported pounds of all AIs, acres treated, acres harvested, and prices for strawberries each year from 2005 to 2009.

The most important fungal diseases of strawberries are Botrytis and powdery mildew. The major fungicides used to control these diseases, by acres treated, in 2009 were sulfur, captan, pyraclostrobin, fenhexamid, myclobutanil, boscalid, cyprodinil, fludioxonil, quinoxyfen, pyrimethanil, propiconazole, and triflumizole. In general, use of fungicides effective against Botrytis fruit rot increased in 2009, and use of those effective against powdery mildew remained roughly the same as in 2008. Botrytis risk increases during warm, wet conditions. Fungicides used to control Botrytis include some that have been registered a long time (captan, fenhexamid, cyprodinil, fludioxonil, thiophanate-methyl, and thiram), boscalid, and the more recently registered QST 713 strain Bacillus subtilis, pyrimethanil, and propiconazole. Acres treated with all of these AIs increased in 2009 except for boscalid, which declined 29 percent. Use continues to increase for propiconazole, pyrimethanil, and QST 713 strain Bacillus subtilis, introduced in 2008, 2006, and 2005, respectively.

Figure 18: Acres of strawberries treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 18

Powdery mildew thrived in 2009, favored by low free moisture on leaves but high humidity. To control powdery mildew, conventional strawberry growers primarily used sulfur, pyraclostrobin, myclobutanil, boscalid, quinoxyfen propiconazole, and triflumizole. Sulfur is inexpensive and is also used by organic growers. In 2009 use of sulfur increased 9 percent, myclobutanil 20 percent, propiconazole 14 percent, quinoxyfen 42 percent, triflumizol 6 percent, and azoxystrobin 63 percent, while use of boscalid decreased 29 percent, pyraclostrobin 21 percent, and potassium bicarbonate 47 percent. The newer products quinoxyfen and propiconazole, introduced in 2007 and 2008, respectively, have had increasing use on summer-planted berries which are particularly susceptible to powdery mildew. Quinoxyfen provides a new multi-site mode of action to control powdery mildew that is different from the demethylation inhibitors, such as propiconazole and myclobutanil, and the strobilurins. It is generally used as a preventative treatment and reduced the use other fungicides. Propiconazole, registered for strawberries in 2008, is a fungistatic demethylation inhibitor like myclobutanil. The newly introduced trifloxystrobin, like other strobilurins, acts on the mitochondrial respiratory pathway to inhibit sporulation and mycelial growth. Pyraclostrobin is frequently used in combination with boscalid; both acres treated and pounds of AI with these two AIs decreased in 2009. Reduced use is thought to be due to reduced efficacy. Use of mefenoxam, effective against red stele, leather rot, and crown rot, increased 19 percent in 2009. Some of the increased use of captan may have been due to its effectiveness on the plant collapse pathogens.

The major insect pests of strawberries are lygus bugs and worms (various moth and beetle larvae), especially in the Central and South Coast growing areas. Until recently, lygus bugs were not considered a problem in the South Coast, but lygus has become a serious threat, probably due to warmer, drier winters and increased diversity in the regional crop complex that support this pest. The major insecticides used in 2009 by acres treated were malathion, Bacillus thuringiensis, naled, bifenthrin, oil, bifenazate, abamectin, fenpropathrin, spinetoram, novaluron, spiromesifen, and acetamiprid.

Table 49: The non-adjuvant pesticides with the largest change in acres treated of strawberries from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Acres treated with all of these major insecticides increased except those treated with spinetoram, which decreased 24 percent, spinosad (down 42 percent), methoxyfenozide (down 14 percent), and methomyl (down 41 percent). Bacillus thuringiensis, spinosad, and the newly registered spinetoram are biological pesticides primarily used against lepidopeteran larvae. Spinosad and spinetoram are also effective against thrips. Spinosad and spinetoram have longer residual action and are generally more effective so do not need to be applied as frequently as Bacillus thuringiensis. Spinetoram, with the same mechanism of action as spinosad, appears to have partially replaced spinosad and Bacillus thuringiensis.

Increase in lygus bug populations in the South Coast growing areas and widespread resistance to pyrethroid pesticides led to increased use of products with other modes of action, in particular, malathion (up 29 percent), Bacillus thuringiensis (up 8 percent), naled (up 53 percent), bifenthrin (up 1 percent), abamectin (up 14 percent), spinetoram, the newly registered acetamiprid (up 27 percent), and novaluron (used for the first time in 2009). Novaluron is an insect growth regulator acting on chitin synthesis in larvae of Coleoptera, Hemiptera, and Lepidoptera. Fenpropathrin (up 9 percent), malathion, spiromesifen (up 22 percent), bifenthrin, and pyriproxyfen (up 44 percent) are effective against whiteflies. Pyriproxyfen is an insect growth regulator registered in 2002. Bacillus thuringiensis and spinosad, as well as pyrethrins (up 92 percent), are available for use by organic growers. Like Bacillus thuringiensis, pyrethrins have short residual activity and so may require multiple sprays.

Increased two-spotted spider mite and red spider mite pressure resulted in a 12 percent increase in use of bifenazate, which is effective and has low toxicity to predatory mites. The use in acres treated of several other pesticides increased in response to mite pressure: spiromesifen (up 22 percent), acequinocyl (up 126 percent), abamectin (up 14 percent), and hexythiazox (up 6 percent). Most conventional growers continue to use bifenazate, which was introduced in 2003. Acequinocyl is effective against cyclamen mite, which is not controlled by bifenazate. The increase in mite problems may be due to relatively warm and dry winter weather, but it may also be due to carryover of mite populations from susceptible summer-planted berries.

Herbicide use increased 107 percent from 8,063 acres in 2008 to 15,629 acres in 2009. For controlling weeds with hard coated seeds, flumioxazin (up 23 percent), oxyfluorfen (up 393 percent), and napropamide (up 85 percent), in combination with clear plastic mulches, are cost effective compared to hand weeding and sequential metam sodium applications.

Strawberry production relies on several fumigants. In 2009, fumigants accounted for about 78 percent of all pesticide AIs by pounds applied in strawberries, and 75 percent of strawberry acres were treated with fumigants, but fumigants accounted for only 2 percent of total cumulative acres treated of all AIs. Acres treated with fumigants in 2009 declined 10 percent. Chloropicrin decreased 8 percent, methyl bromide use decreased 15 percent, 1,3-dichloropropene (1,3-D) use decreased 7 percent, and metam-sodium use decreased 6 percent. Newer fumigant formulations have shown increased effectiveness against soil-borne fungal pathogens. Methyl bromide is used primarily to control pathogens and nut sedge. Metam-sodium is generally more effective in controlling weeds, but less effective than 1,3-D or 1,3-D-plus- chloropicrin against soil-borne diseases and nematodes. Fumigants usually are applied at higher rates than other pesticide types, such as fungicides and insecticides. Fumigants are applied at high rates, in part because they treat a volume of space rather than a surface area such as leaves and stems of plants. Thus, the pounds applied are large relative to other pesticide types even though the number of applications or number of acres treated may be relatively small.

Peaches and Nectarines

California ranks first in the United States in peach and nectarine production. In 2009 the state grew 74 percent of all U.S. peaches (including 55 percent of fresh market peaches and all of the processed peaches) and 90 percent of nectarines. Most freestone peaches and nectarines are produced in the central San Joaquin Valley and are sold on the fresh market. Clingstone peaches, largely grown in the Sacramento Valley, are used exclusively for processing into canned and frozen products, including baby food and juice. Nectarine- and freestone peach-bearing acreage declined from 31,000 acres each in 2008 to 29,000 and 28,000 acres, respectively, in 2009, while clingstone peach acreage declined from 25,000 to 24,500 acres. Peaches and nectarines are discussed together because pest management issues for the two crops are similar.

Peach and nectarine acreage treated with the major categories of pesticides has fluctuated from year to year since 1994 (Table 50). Data for most types of pesticide do not show substantial increasing or decreasing use trends (Figure 19). Total acres treated with pesticides and total pounds of pesticide AI applied decreased from 2008 levels 5 percent and 7 percent, respectively (Table 51). Acres treated with all types of pesticide active ingredients declined.

Table 50: Total reported pounds of all active ingredients (AI), acres treated, acres bearing, and prices for peaches and nectarines each year from 2005 to 2009. Bearing acres from 2004 to 2008 are from CDFA, 2009; bearing acres in 2009 are from NASS, July 2010; marketing year average prices from 2004 to 2006 are from NASS, August 2009; marketing year average prices from 2007 to 2009 are from NASS, July 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 51: Percent difference from previous year for reported pounds of all AIs, acres treated, acres bearing, and prices for peaches and nectarines each year from 2005 to 2009.

Drought conditions continued in California for a third year. The 2008-2009 winter season brought only 75 percent of normal total rainfall statewide. Plenty of wintertime chill hours left trees “well rested” before spring bloom. There was frost damage in March, but in many areas the damage was light enough to be considered an aid to thinning, which reduced labor costs. With generally favorable weather, average clingstone peach yield per acre increased about 14 percent compared to 2008, producing the second biggest crop on record. Nevertheless, the price per ton declined only slightly from a 2008 record high. Frost damage, tree removal, and acreage reductions due to water shortage contributed to a 19 percent reduction in freestone peach production and a 30 percent drop in nectarine production. Nectarine prices held up well, but prices for freestone peaches were low: for four to five weeks, prices stayed at or below the cost of production. As in 2008, financial hardship forced some freestone peach and nectarine growers and packers out of business. Growers continued to be strongly motivated to cut production costs.

Figure 19: Acres of peaches and nectarines treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 19

Total peach and nectarine acres treated with insecticides and miticides decreased about 4 percent in 2009, roughly in line with the decrease in bearing acreage. There were thrips problems at bloom in some areas and continuing drought favored mite infestations. The most-used insecticides by acres treated in peaches and nectarines were: oils; esfenvalerate; and the oriental fruit moth (OFM) mating disruption pheromones E-8-dodecenyl acetate, Z-8-dodecenyl acetate, and Z-8-dodecenol. Oils are applied during the dormant season to forestall outbreaks of scales, mites, and moth pests. Esfenvalerate is a broad-spectrum chemical that may be used in dormant applications or during the growing season, often as an alternative to the more expensive OFM pheromones. Especially during an economic downturn, rebates and price reductions as well as efficacy affect choice of pesticide products. Table 52 lists AIs with the largest changes in acres treated from 2008 to 2009. Acres treated with esfenvalerate declined slightly more than bearing acreage, and OFM pheromones slightly less. Use of lambda -cyhalothrin, a substitute for esfenvalerate, increased. Acres treated with formetanate hydrochloride declined. Formetanate hydrochloride is an older broad-spectrum insecticide that controls thrips but triggers mite problems (although it is sometimes used as a miticide). In contrast, acres treated with spinetoram, the main alternative for thrips control, and with spirodiclofen, a contact miticide, increased. Spinetoram and two other relatively new and increasingly used AIs, chlorantraniliprole and indoxacarb, are effective against OFM, peach twig borer, and katydids. Spinosad is being replaced by spinetoram, which received maximum residue levels in 2009 that allow its use on fresh produce for export. Methoxyfenozide use may have decreased at least in part because of ineffectiveness against katydids. Residue issues and declining effectiveness for moth control may have contributed to a significant decrease in phosmet use, which is consistent with a longer-term trend away from high-risk pesticides.

Table 52: The non-adjuvant pesticides with the largest change in acres treated of peaches and nectarines from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Although February, May, and June rainfall was above average during the otherwise relatively dry 2008-2009 rainy season, total peach and nectarine acres treated with fungicides decreased 1 percent. The most-used fungicides by acres treated were sulfur, propiconazole, copper-based pesticides, ziram, iprodione, and pyraclostrobin/boscalid. Sulfur is the standard treatment for powdery mildew. Propiconazole is a low-dose chemical applied against fungi and powdery mildew. Ziram and copper- based pesticides are effective for leaf curl and shot hole disease, and ziram also controls scab. Pyraclostrobin and boscalid are reduced-risk alternatives for mildew and fungus control. Acres treated with ziram decreased significantly in 2009, whereas acres treated with copper-based pesticides increased (Table 52). Newer, more user-friendly copper-based pesticides have become available. Fluctuations in product prices as well as the relative efficacy of different AIs may also have influenced fungicide application decisions.

When profit margins shrink, some growers cut back on weed control. Cost-cutting and continued suppression of weeds by the third year of drought likely contributed to the 10 percent reduction in total acres treated with herbicides in 2009. As in 2008, the most-used herbicides by acres treated were glyphosate, oxyfluorfen, 2,4-D, pendimethalin, and paraquat. Acres treated with all those AIs except oxyfluorfen decreased significantly, and the total pounds of oxyfluorfen applied decreased. Although fewer acres were treated with glyphosate (Table 52), total pounds of glyphosate applied rose 11 percent. Weed resistance to glyphosate is increasing, causing growers to apply higher doses and/or to rely increasingly on alternatives.

In peach and nectarine orchards, most fumigants are used for soil treatments to suppress nematodes, pathogens, and weeds. Total peach and nectarine acres treated with fumigants declined 23 percent in 2009. That change may be associated with industry tree-removal programs that bring production more in line with demand, the replanting of peach and nectarine acreages to other crops, and environmental regulations. The most widely applied pre-plant soil fumigant is 1,3-D, followed by methyl bromide and chloropicrin. The post-plant fumigant sodium tetrathiocarbonate is also used against soil pests, including for control of ring nematode in response to bacterial canker problems. Growers appear to be reducing soil fumigant application rates and/or moving from broadcast application to spot or row treatments. Those changes save money and also respond to regulatory encouragement to reduce emissions of volatile organic compounds (VOCs), which are precursors to ground level ozone formation. Methyl bromide is expensive and increasingly restricted because it depletes stratospheric ozone. Changing relationships between nematode infestations, rootstock choices, and application patterns also affect fumigant selection and use from year to year.

Methyl bromide is currently the only fumigant used to treat fresh peaches and nectarines for export. In 2009, pounds of methyl bromide applied post-harvest declined 17 percent. This is consistent with a 36 percent decrease in export shipments of freestone peaches and nectarines in 2009. Near-record levels of production and exports in 2008, low consumer demand due to global recession, and currency exchange rate fluctuations all played a role in reducing export shipments.

Carrots

California is the largest producer of fresh market carrots in the United States, accounting for 83 percent of the U.S. production of 2.2 billion pounds in 2009. California has four main production regions for carrots: the San Joaquin Valley (Kern County), the central coast in San Luis Obispo and Santa Barbara counties (Cuyama Valley) and Monterey County, the low desert (Imperial and Riverside counties), and the high desert (Los Angeles County). The San Joaquin Valley accounts for more than half the state’s acreage.

Total acres of carrots planted decreased 1 percent while pesticide use (as acres treated) in carrots decreased 31 percent in 2009 compared to 2008 (Table 54) and pounds of pesticide AI applied decreased 44 percent. Reported use of all major pesticide types decreased in terms of acres treated with the exception of plant growth regulators. The most-used non-adjuvant pesticides by acres treated were mefenoxam, linuron, sulfur, pendimethalin, pyraclostrobin, copper-based pesticides, chlorothalonil, metam- sodium, and iprodione. Fungicide use decreased the most, followed by herbicides and adjuvants (Figure 20): From 2008 to 2009 acres treated with fungicides decreased 35 percent while pounds AI decreased 34 percent, and acres treated with herbicides decreased 19 percent while pounds AI decreased 9 percent. Pounds of fumigants decreased 40 percent from the previous year.

Table 53: Total reported pounds of all active ingredients (AI), acres treated, acres planted, and prices for carrots each year from 2005 to 2009. Planted acres from 2004 to 2008 are from CDFA, 2009; planted acres in 2009 are from NASS, January 2010; marketing year average prices from 2004 to 2007 are from NASS, August 2009; marketing year average prices from 2008 to 2009 are from NASS, January 2010. Acres treated means cumulative acres treated (see explanation p. 8).

Table 54: Percent difference from previous year for reported pounds of all AIs, acres treated, acres planted, and prices for carrots each year from 2005 to 2009.

The most-applied fungicides in 2009, by acres treated, were mefenoxam, sulfur, pyraclostrobin, copper-based pesticides, chlorothalonil, iprodione, and fenamidone. Alternaria leaf blight, a foliar disease, is generally controlled by iprodione, chlorothalonil, pyraclostrobin, or azoxystrobin. In terms of acres treated, iprodione use decreased 49 percent, chlorothalonil 2 percent, sulfur 48 percent, pyraclostrobin 34 percent, and azoxystrobin 42 percent. New carrot varieties became available that are resistant, especially to diseases affecting carrot tops, and this may account for a decrease in fungicide use in 2009 compared to 2008. Additionally, the cool weather in 2009 may have contributed to a decrease in Alternaria pressures as it needs warmer temperatures to thrive. Powdery mildew is primarily controlled by sulfur, which is inexpensive and especially popular with organic growers. Sulfur use decreased in 2009 relative to 2008 because cool weather conditions in 2009 were not optimal for powdery mildew infection. As in most recent years, cavity spot is a major, troublesome soil-borne fungal disease that is commonly controlled by applying mefenoxam, fenamidone, cyazofamid, or the soil fumigant metam-sodium. In terms of acres treated, mefenoxam use decreased 28 percent and fenamidone 63 percent from 2008 to 2009. Many hoped that fenamidone would be an effective replacement for mefenoxam, which has pest resistance issues. However, many growers moved back to mefenoxam. Cyazofamid, another product used to control cavity spot, became available in 2008. Although its use has greatly increased from 2008 to 2009, growers are reluctant to use it as maximum residue limits for cyazofamid have not been fully established by major trading countries.

Figure 20: Acres of carrots treated by all AIs in the major types of pesticides from 1994 to 2009.

Figure 20

The main herbicides used in carrot production in terms of acres treated were linuron, pendimethalin, fluazifop-p-butyl, trifluralin, clethodim, and EPTC. The use of linuron, a postemergence herbicide that provides good control of broadleaf weeds and small grasses, decreased 21 percent. Trifluralin is a preemergence herbicide that complements linuron for weed management; its use decreased 45 percent. Use of fluazifop-p-butyl, a selective postemergence phenoxy herbicide used for control of annual and perennial grasses, decreased 30 percent. Pendimethalin, another selective herbicide, had a 14 percent decrease in use. However, clethodim and EPTC use increased in 2009. In terms of acres treated, clethodim increased 13 percent. EPTC had the largest increase of herbicides used: from 226 treated acres in 2008 to 4,255 acres in 2009.

Insects are not generally major problems in carrot production except for whiteflies, which are controlled with esfenvalerate and methomyl. The major insecticides used in 2009 in terms of acres treated were esfenvalerate, Bacillus thuringiensis, diazinon, spinosad, methomyl, and bifenthrin. Acres treated with esfenvalerate decreased 54 percent and spinosad 44 percent in 2009 compared to 2008. Although generally used against whitefly, esfenvalerate and spinosad are also used to control flea beetle, leafhoppers, and cutworms. Acres treated with methomyl decreased 20 percent in 2009 compared to 2008. This carbamate pesticide is effective against cutworms and leafhoppers as well as whiteflies. Diazinon use decreased 28 percent in 2009 relative to 2008. The use of Bacillus thuringiensis increased 8 percent. Bifenthrin, a pyrethroid used to control cutworm and crown root aphids, increased 76 percent.

Table 55: The non-adjuvant pesticides with the largest change in acres treated of carrots from 2008 to 2009. This table shows acres treated with each AI in each year from 2005 to 2009, the change in acres treated and percent change from 2008 to 2009.

Most carrot production relies on the fumigants metam-sodium, 1,3-dichloropropene (1,3-D), potassium N-methyldithiocarbamate (metam-potassium), and to a lesser extent, chloropicrin. These fumigants are used to manage nematodes and may provide other benefits such as weed and soil-borne disease control. In 2009, fumigants accounted for about 80 percent of the total pounds of pesticide AIs applied to carrots. Fumigant use, in terms of pounds of AI, decreased 40 percent from 2008 to 2009. Similarly, acres treated with fumigants decreased 47 percent. The number of acres treated with metam- sodium, 1,3-D, metam-potassium, and chloropicrin decreased 39, 64, 55, and 78 percent respectively. The decrease in fumigant use may have been due in part to an increase in use restrictions. As a result, growers are not using as many fumigants and may have also switched to cultural practices including cover cropping and longer rotations. Further, the relatively cool spring and summer may have caused lower pest pressures, possibly resulting in the decreased fumigant use and the overall decrease in pesticide use.

Sources of Information

Adaskaveg, J., Gubler, D., Michailides, T, and B. Holtz. 2010. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops. UC Davis, Department of Plant Pathology; Statewide IPM Program; and UC Kearney Agricultural Center. Linked to Pest Management Guidelines on the UC IPM Web site.

Ag Alert. 2009. California Farm Bureau. Various issues.

Almond Board of California.

California Canning Peach Association online “Peach Facts”

California Drought Update. July 31, 2009.

California Tree Fruit Agreement Annual Report 2009.

California Department of Food and Agriculture (CDFA), 2009. California Agriculture Resource Directory 2009-2010.

California Farm Bureau. 2009. Ag Alert. Various issues.

County Agricultural Commissioners

Growers

NASS, July 2005, Agricultural Prices 2004 Summary. USDA. Pr 1-3 (05)a.

NASS, July 2006, Agricultural Prices 2005 Summary. USDA. Pr 1-3 (06).

NASS, January 2007, Vegetables 2006 Summary, Vg 1-2 (07)

NASS, July 2007, Agricultural Prices 2006 Summary. USDA. Pr 1-3 (07).

NASS, July 2008, Agricultural Prices 2007 Summary. USDA. Pr 1-3 (08)a.

NASS, January 2009, Vegetables 2008 Summary, Vg 1-2 (09)

NASS, August 2009. Agricultural Prices 2008 Summary, Pr 1-3 (09).

NASS, September 2009, Citrus Fruits 2009 Summary, Fr Nt 3-1 (09)

NASS, January 2010, Vegetables 2009 Summary, Vg 1-2 (10)

NASS, February 2010, Crop Values 2009 Summary

NASS, March 2010, California Grape Acreage Report 2009 Summary

NASS, April 2010, 2009 California Almond Acreage Report

NASS, June 2010, Acreage

NASS, July 2010. Noncitrus Fruit and Nuts 2009 Summary

Pest Control Advisors

PPN Network Connection. 2009. Online newsletter of the California Tree Fruit Agreement. Various issues.

Private Consultants

University of California Cooperative Extension Area IPM Advisors

UC Cooperative Extension Farm Advisors

UC Cooperative Extension Specialists

UC Researchers

Western Farm Press. 2009. Newspaper published two or three times per month. Various issues.




The following reports present information on statewide pesticide use for 2009. Both versions of the Pesticide Use Report are available on a cd (send requests to mwilliams@cdpr.ca.gov), can be found on DPR’s Web site, or can be downloaded from DPR’s FTP site.

VI. SUMMARY OF PESTICIDE USE REPORT DATA 2009 INDEXED BY COMMODITY

For each commodity, the chemical that was used, total pounds applied, the number of agricultural applications made, and the amount of commodity treated are summarized.

VII. SUMMARY OF PESTICIDE USE REPORT DATA 2009 INDEXED BY CHEMICAL

For each chemical, the commodity on which it was used, total pounds applied, the number of agricultural applications made, and the amount of commodity treated are summarized.