Chlorpyrifos Protects

Chlorpyrifos is an important tool for Integrated Pest Management (IPM) throughout the United States. In fact, many of our farmers rely on it, not only to protect their livelihoods from insect pest damage but also to minimize the damage to beneficial insects that also help control pests. Of the dozens of food and non-food crops (e.g., cotton, sod, Christmas trees), the most important crops protected by chlorpyrifos (based on importance of use and volume of sales) are as follows:

In order to provide some perspective for the importance of chlorpyrifos to agriculture in the U.S., the following pages review why each of these crops is important to our food supply and economy.

For further discussion of vital crops protected by chlorpyrifos and other insecticides, view a summary of the CropLife Foundation white paper The Value of Insecticides in U.S. Crop Production or access full details by crop or state .

Soybeans and Chlorpyrifos

Economic Importance of the Crop

Soybeans are the largest source of protein feed and vegetable oil in the world. The U.S. is the world's leading soybean producer and exporter with a total crop value of over $27 billion in 2008. The United States accounts for 40% of the world's soybean trade. One third of world oilseed production comes from soybeans produced in the U.S., and domestic soybeans provide about 70% of U.S. consumption of edible fats and oils.

Where and How Much Is Grown

Over the past five years, about 72 million acres of soybeans were grown annually in the U.S. Five Midwestern states (Iowa, Illinois, Minnesota, Indiana and Missouri) account for half the acres, with Iowa leading in terms of most acres planted.

Why Chlorpyrifos Is Needed

Because of the recent introduction and establishment of the soybean aphid, use of chlorpyrifos to protect U.S. soybeans has expanded from 200,000 acres in 2004 to nearly eight million acres in 2008, with the product being applied to about 11% of soybean acres planted that year. In 2007 soybeans became the crop with the highest annual usage of chlorpyrifos in terms of treated acres and accounted for over one-fourth of total chlorpyrifos volume in the United States.

The number one soybean pest in the Midwest and Plains regions, the soybean aphid, causes leaf curling and stunting of plant growth. Since 2000, heavy soybean aphid infestations have caused economic yield losses of up to 45% in untreated fields. The soybean aphid is now present in 20 states across the Plains and into the Northeast and South. Due to its fast knockdown and control of other pests, chlorpyrifos is the leading product used against soybean aphids.

Grower Perspective

“Chlorpyrifos is an extremely important insecticide for soybean production in Minnesota, as well as most of the upper Midwest. Chlorpyrifos effectively controls two very significant pests in soybean production — spidermites and soybean aphids. Infestations of spidermites can be sporadic [and when they] do occur, yield reductions of greater than 50 percent can result. Based on University of Minnesota research, chlorpyrifos is the product of choice for controlling spidermites in soybeans… Chlorpyrifos is one of only two types of products that have proven to provide effective control of soybean aphids. The other products are synthetic pyrethroids… and their use has sometimes resulted in the need to make supplemental applications of chlorpyrifos to control spidermites.”

– Minnesota Soybean Growers Association.

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Citrus and Chlorpyrifos

Economic Importance of the Crop

The U.S. is the second largest orange-producing country in the world with a total farm gate value of $2.6 billion.3 Florida is the leading U.S. state for orange production, followed by California. Florida's annual orange crop was about 7.6 million tons in 2007 and 2008 while California's was about 2.2 million tons. Most of California's oranges are marketed as fresh fruit for domestic use and export, while the majority of Florida oranges are processed.

Where and How Much Is Grown

In 2007, there were 972,662 acres of citrus grown in the U.S., with the top citrus producing states being Florida (oranges and grapefruit), California (oranges, lemons, and grapefruit), Texas (grapefruit) and Arizona (lemons). Florida and California account for 90% of U.S. citrus acres. California produces approximately 77% of the U.S. lemon crop, with Arizona producing the rest. Over the past three seasons, California produced an average of 754 million tons of lemons annually, with nearly two-thirds of the crop going to the fresh fruit market.

Why Chlorpyrifos Is Needed

Nationally, chlorpyrifos is the third most frequently applied pest control product for citrus, accounting for 12% of treated acres. Chlorpyrifos-treated acres have more than doubled in recent years to well over 400,000 with more than 80% of the treatments used against pests of oranges. Most of this increased use is attributed to introduction into Florida of the Asian citrus psyllid, a bacteria vector causing citrus greening. To slow the spread of this disease, Florida citrus crops are currently being treated with broad-spectrum pesticides up to eight times per year. While pesticides can reduce the number of psylla, adult psyllids can transmit the disease faster than some pesticides can control them.

In California, chlorpyrifos is one of the most frequently used active ingredients for control of scale insects, especially in oranges and lemons. Scale control in California citrus is a high-anxiety issue for growers because scale significantly reduces the premium received for fresh market citrus and can result in shipments being rejected for export. Chlorpyrifos is also used because it has minimal impact on the beneficial Aphytis wasp, which is important for late season biocontrol of California red scale populations.

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Grapes and Chlorpyrifos

Economic Importance of the Crop

The U.S. wine, grape and grape products industries contribute more than $162 billion annually to the American economy.

Where and How Much Is Grown

The U.S. wine, grape and grape products industries are largely concentrated in California, which accounts for virtually all table grapes and raisins and roughly 90% of the nation's wine production. Almost all U.S. raisins are produced in California's San Joaquin Valley. California dominates the grape market with about 96% of the acres. Wine grapes accounted for 58% of the acres grown.

Why Chlorpyrifos Is Needed

Chlorpyrifos is critically important to grape growers for use against mealybugs, one of the most important pests of grapes, and especially table grapes. Chlorpyrifos is the leading pest control product used on table grapes, accounting for 14% of all active ingredient acres. For wine grapes and raisins, chlorpyrifos accounts for approximately 6% of total acres treated. Raisin grapes are not typically treated for mealybugs.

Chlorpyrifos is considered by the University of California to be the foundation of an effective and reliable mealybug management strategy. Prior to the 1996 registration of chlorpyrifos for use on dormant grapes, the only option for managing grape mealybug was ground spray suppression of ants (i.e., ants tend mealybugs, so controlling the ants also helps control mealybugs). Today most chlorpyrifos used against grape pests is applied in California and the Pacific Northwest as a dormant season spray just prior to bud break in table and wine grapes for control of grape, vine and obscure mealybugs.

Chlorpyrifos is also used as a post-harvest vine treatment for control of vine mealybug and is the leading product used against this pest in California grapes. Post-harvest applications have been very effective, since new infestations are generally discovered during harvest, and a timely treatment is critical for limiting the spread of the pest to other vineyards. Since vine mealybug is now present throughout all California grape growing regions, the use of chlorpyrifos for post-harvest treatment of grapes has significantly increased in recent years, especially since there is no effective biological control for this pest.

Grower Perspective

“For California wine grapes, chlorpyrifos predominantly is used for managing the recently introduced vine mealybug, a significant problem in some regions and threat across the state… Chlorpyrifos is one of the few registered products and most efficacious for controlling vine mealybug, particularly its spread to noninfested areas. When used, the material is carefully applied at delayed dormancy or post-harvest for direct kill, or to suppress ants that impede biological control of mealybugs… It is important…to maintain all safe and effective uses of chlorpyrifos in California wine grapes, at least until other efficacious alternatives become available.”

– California Association of Wine Grape Growers.

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Tree Nuts and Chlorpyrifos

Economic Importance of the Crop

Tree nut crops include almonds, walnuts and pecans, which are grown on about 1.7 million U.S. acres. Since the mid-2000s, U.S. tree nut production has generated on average about $4 billion in annual U.S. farm cash receipts.

Where and How Much Is Grown

Nearly 90% of U.S. tree nut production takes place in California, which accounts for virtually all almonds and walnuts. With their only tree nut crop being pecans, Georgia, New Mexico, and Texas each make up about two to three percent of total tree nut output and together produce nearly three-quarters of the U.S. pecan crop.

Why Chlorpyrifos Is Needed

  • Almonds – Chlorpyrifos is used by growers during May and at hull split against peach twig borer and navel orangeworm, two primary almond pests that feed directly on nutmeats, causing substantial reductions in yield and quality. Dormant applications are used against overwintering peach twig borer, San Jose scale and mites. Other uses of chlorpyrifos include ant suppression on orchard floors. Chlorpyrifos is a product of choice for growers because it offers effective control of almond pests without flaring spidermites unlike some alternative treatments. Orchards using chlorpyrifos typically use only one, or at most two, treatments per year.
  • Codling moth damage done to walnuts.
  • Walnuts – Chlorpyrifos is the product most widely used against walnut pests, with more than 90% of treatments being made for control of codling moth. Codling moth damage can cause trees to drop developing nutlets, make developed nut kernels unmarketable and can provide breeding sites for other walnut damaging pests. Chlorpyrifos is used against walnut husk fly and walnut aphid as well. The product also plays an important role in integrated pest management programs for walnuts.
  • Pecans – Chlorpyrifos is used as an effective and cost-competitive treatment against pecan nut casebearer and black pecan aphid on about half the treated acres in all pecan-producing states. Black pecan aphid feeding can cause leaf damage and rapid leaf shed, resulting in reduced nut quality and yield reductions in the following season. Pecan nut casebearer feeds directly on nutmeat, and one larva can destroy an entire nut cluster. Overwintering larvae also cause damage by tunneling through and killing new shoots in spring. Chlorpyrifos was used on about 200 000 pecan acres in Georgia and 100 acres in Texas in 2007, where it is the leading product used against pecan pests in these two states.

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Field Corn and Chlorpyrifos

Economic Importance of the Crop

Corn is the most widely produced feed grain in the U.S., accounting for more than 90% of the total value and production of feed grains. Most of the crop is used as the main energy ingredient in livestock feed. Corn is also processed into a multitude of food and industrial products including starch, sweeteners, corn oil, beverage and industrial alcohol, and fuel ethanol. The U.S. is a major player in the world corn trade market, with approximately 20% of the corn crop exported to other countries. According to the National Corn Growers Association, the value of the U.S. corn crop harvested in 2008 was $52 billion.

Where and How Much Is Grown

The number of corn acres the U.S. grew dramatically in 2007 and 2008, increasing from an average of around 80 million acres in 2004 to a record 92.2 million acres in 2007 and 86.7 million acres in 2008. Most field corn is grown in the Midwest with five states – Iowa, Illinois, Nebraska, Minnesota and Indiana – accounting for 56% of planted acres.

Why Chlorpyrifos Is Needed

Above- and below-ground pests such as the corn rootworm, black cutworm, western bean cutworm, and European corn borer can destroy corn, minimizing the yield that growers can produce on each acre of their farming operation. The U.S. Department of Agriculture estimates that corn rootworm alone causes more than $1 billion in lost revenue each year, which includes $800 million in yield loss and $200 million in treatment costs, making it the costliest pest in corn.

Increased adoption of corn with inbred insect-resistance traits that provide protection against a number of pests – including the corn rootworm and European corn borer – has greatly reduced the need to apply insecticides for corn. The amount of chlorpyrifos used to protect field corn has declined nearly 74% since the adoption of insect-resistance traits. To minimize the potential for insect resistance, however, growers raising insect-resistant corn are required to plant a certain percentage of acres to conventional corn, and chlorpyrifos is important for pest control on these acres.

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Entomologist Perspective

“[C]hlorpyrifos is the insecticide of choice for control of aphids and spidermites in many field crops, because of the ability of spidermites, for example, to develop insect resistance and to ‘flare up’ (rapid population density increases) when other insecticides….are used for control.”

– Dr. Janet Knodel, Department of Entomology, North Dakota State University.

Alfalfa and Chlorpyrifos

Economic Importance of the Crop

Alfalfa is the fourth most widely grown crop in the U.S. with over 20 million acres in production and an estimated annual value of $11.7 billion. Alfalfa hay is primarily used as feed, mostly for dairy cows, but also for horses, beef cattle, sheep and other farm animals. Essentially, without alfalfa, there is no dairy industry.

Feeding on an alfalfa leaf.

Where and How Much Is Grown

More than 20 million acres of alfalfa were grown in the U.S. in 2008. West and Plains regions account for about 60% of planted alfalfa acres.

Why Chlorpyrifos Is Needed

Chlorpyrifos is one of the most widely used insecticides for U.S. alfalfa, accounting for over 19% of total insecticide-treated acres. The West and Plains regions account for 78% of all treated alfalfa acres, and in these two regions, chlorpyrifos is the most frequently used insecticide. Three target pests in alfalfa – alfalfa weevil, armyworms, and aphids – account for 54% of total chlorpyrifos-treated acres. Alfalfa weevil feeding causes bronzing of leaves, skeletonization and in extreme cases complete defoliation of the plant. Armyworms can also skeletonize foliage. Chlorpyrifos is the leading product used to protect alfalfa from these pests.

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References

Gianessi L. The Value of Insecticides in U.S. Crop Production. CropLife Foundation. March 2009.
http://croplifefoundation.files.wordpress.com/2012/07/insecticide-benefits-execsum.pdf. Accessed April 21, 2009.

United States Department of Agriculture. USDA Economics, Statistics and Market Information System (ESMIS).
http://usda.mannlib.cornell.edu/MannUsda/homepage.do . Accessed June, 2009.