Benefits and Uses by Crop
Insect pests cause billions of dollars' worth of damage and threaten our food supply, our property, our health, and the livelihood of growers. Insects have a remarkable ability to adapt to environmental pressures, to changes in cropping systems, cultural practices and climate, and to tolerate or resist management strategies, including insecticides. To protect our food supply and satisfy the needs of a growing population, growers need full access to a broad range of effective and sustainable insect management tools to manage insect infestations. Insecticides, such as chlorpyrifos, have played, and will continue to play, an important role in a sustainable insect management strategy:
Chlorpyrifos products in the U.S. underwent a rigorous re-registration process that began in 1984 and concluded in 2006. This included evaluation for potential human health and environmental impacts as well as a cumulative consumer risk assessment for the organophosphate class of insecticides.2 A multi-year regulatory review of chlorpyrifos by the Environmental Protection Agency (EPA) known as Registration Review opened in early 2009.
Follow the links below for crop-specific information about target pests and chlorpyrifos use.
| Crop | Target Pests |
|---|---|
| Alfalfa | Alfalfa weevil, armyworms, aphids, potato leafhoppers |
| Brassica Vegetables (Cole Crops) (Broccoli, Cauliflower, Cabbage, Kale, Rutabaga, Turnips, etc.) |
Cabbage maggot, aphids |
| Citrus | Scale insects, mealybugs, Asian citrus psyllid, rust mite, citrus leaf miner; katydids. |
| Corn, Field | Corn rootworm, cutworms, white grub, European corn borer |
| Corn, Sweet | corn earworm, armyworms, corn rootworm (larvae and adult), cutworms, seed corn maggot, wireworms |
| Cotton | Cotton aphid, Lygus bug, armyworms, pink bollworm |
| Grapes | Mealybugs, cutworms, ants |
| Mint | mint root borer |
| Onions | Onion maggot |
| Peanuts | Lesser cornstalk borer, corn rootworm, white mold |
| Pome Fruits (Apples, Pears) | San Jose scale, rosey apple aphid, pandemis leafroller oblique-banded leafroller, climbing cutworms, American plum borer |
| Soybeans | Soybean aphid, bean leaf beetle, grasshoppers, spider mites |
| Stone Fruits (Peaches, Nectarines, Cherries, Plums) | San Jose scale, peach twig borer, ,peach tree borer, lesser peach tree borer, American plum borer |
| Sugar Beets | cutworm, wireworm, sugarbeet root maggot, armyworms, grasshoppers |
| Sweet Potatoes | Wireworms, southern corn rootworm, flea beetles |
| Tree Nuts (Almonds, Pecans, Walnuts, etc.) | San Jose scale, peach twig borer, navel orangeworm, codling moth, walnut husk fly, walnut aphid, pecan nut casebearer, black pecan aphid |
| Wheat | Aphids, grasshoppers, cereal leaf beetle, orange wheat blossom midge |
Alfalfa
Value 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.
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.
Brassica Vegetables (Cole Crops)
Value of the Crop
Over 200,000 acres of Brassica vegetables were harvested in the US. in 2008 with a combined farm gate value of $1.34 billion for broccoli, cabbage and cauliflower, the three major crops.
Where and How Much Is Grown
Nearly 75% of all U.S. Brassica vegetable crop production occurs in California. Broccoli is the leading Brassica crop accounting for 53% of all Brassica acres. Although California represents just 21% of all U.S. broccoli growers, with 127,000 acres in production, the state accounts for 85% of total harvested broccoli acreage. California also grows 14,800 acres of cabbage and 33,700 acres of cauliflower. Cabbage is grown commercially in ten states; and cauliflower in two: California and Arizona.
Why Chlorpyrifos Is Needed
Chlorpyrifos is one of the most widely used pest control products in broccoli and cauliflower. The most important pests in Brassica crops where chlorpyrifos is used are cabbage maggot and cabbage aphids. Cabbage aphid feeding results in leaf curl, wilting, dwarfing and, in severe infestations, plant death. Badly infested plants are covered with a mass of small soggy aphids, facilitating rot in the dying leaves. Cabbage maggots riddle the roots of brassica crops with tunnels, providing ready access for pathogens that cause blackleg and bacterial soft rot. There are currently few effective alternatives to chlorpyrifos for control of cabbage root maggot.
Additionally, chlorpyrifos provides growers with another mode-of-action to rotate with other insecticides, which helps prevent insect resistance from developing. Few products are registered for use against some major Brassica pests, and without chlorpyrifos, resistance would develop in these pests at an accelerated rate.
Citrus
Value 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
(to almonds)
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.
Corn, Field
Value 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.
Corn, Sweet
Value of the Crop
According to the U.S. Department of Agriculture, commercial sweet corn production in 2007 surpassed $860 million in value, with over 631,000 acres under production. Of all processed vegetables, processed sweet corn accounted for the second largest and second most valuable crop in 2007.
Where and How Much Is Grown
While sweet corn is grown in all 50 states, the production of sweet corn for processing is heavily concentrated in the upper Midwest and the Pacific Northwest, while Coastal states dominate the commercial fresh sweet corn market. Florida is the leading producer of fresh sweet corn, followed by California, New York and Georgia.
Why Chlorpyrifos Is Needed
In 2008, about 100,000 acres of sweet corn were treated with chlorpyrifos, with the largest use of product being as a foliar treatment in the Southeastern and Western states. In the Midwest and Atlantic regions, chlorpyrifos is primarily used as an at-plant soil insecticide.
Because of its broad spectrum control, foliage applications of chlorpyrifos are used on sweet corn to control armyworms, corn earworm, corn rootworm adults, cutworms, grasshoppers and aphids. At-plant soil applications of chlorpyrifos are used for corn rootworm larvae, cutworms, lesser corn stalk borer, seed corn maggot and wireworms. In Western states, armyworms and corn earworm are the most important insect pests of sweet corn. In the Midwest and Atlantic regions corn rootworm is the target insect pest for most chlorpyrifos treatments. In California, chlorpyrifos is used against symphylans, which have developed into a particularly difficult pest.
Because many insect pests of sweet corn (such as corn earworm) require multiple applications for control, growers need effective products for use as alternatives in rotations to delay insect resistance. Chlorpyrifos is valuable to growers for insect resistance management programs because it offers a different mode of action than carbamates and pyrethroids.
Cotton
Value of the Crop
According to the U.S. Department of Agriculture, the cotton industry contributes more than $25 billion in products and services to the U.S. economy.
Where and How Much Is Grown
In 2008, more than 9.3 million cotton acres were planted in the U.S. with nearly 85% of them in Southern states. In California and Arizona, cotton is grown on more than 400,000 acres, mostly in the San Joaquin Valley. Since 2000, nationwide cotton losses to insect pests have been below 5%. This is attributed to the boll weevil eradication program and widespread use of cotton with inbred insect resistance traits. Today, around 90% of U.S. cotton acreage uses some type of insect resistance trait.
Why Chlorpyrifos Is Needed
In recent years, chlorpyrifos use has typically represented less than 0.5% of all cotton acres treated for insects. However, use of chlorpyrifos continues to be important for cotton because it is an alternative product used in rotation with other insecticides to prevent insect resistance and also for use on pests that are not controlled by insect-resistant cotton.
The majority of chlorpyrifos applied to cotton in recent years has been in California and Arizona for control of cotton aphid, Lygus bug and late season armyworm populations. According to a study by Mississippi State University, since the adoption of cotton with inbred insect resistance traits (which primarily control chewing insects) Lygus, or plant bugs, have emerged as the new number one U.S. cotton pest. Plant bugs infest about 61% the current acreage with Arizona, California, Louisiana and Missouri reporting the highest percentage of losses to these insects. Chlorpyrifos is important for control of these pests.
Grapes
Value 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 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 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.
Mint
Value of the Crop
Farm gate value of the nine million pounds of mint oil produced annually in the U.S. has been estimated by the Crop Protection Research Institute at $115 million, which in final product form translates to a $3.5 billion domestic market. The toothpaste and chewing gum industries use about 90% of the peppermint and spearmint oils produced in the U.S., with lesser amounts being used in the confectionary, pharmaceutical and liqueur flavoring trades. The U.S. is the largest producer of peppermint and spearmint oils in the world and accounts for 70% of the world's mint oil production.
Where and How Much Is Grown
In 2008, 60,000 acres of peppermint and 20,400 acres of spearmint were produced, primarily in Oregon, Washington, Idaho, Montana, California, South Dakota, Indiana, Michigan and Wisconsin.
Why Chlorpyrifos Is Needed
Few insecticides are registered for use against pests of mint. Chlorpyrifos is used against variegated cutworm, mint looper, mint flea beetle and mint aphid, but the most important use is for effective control of mint root borer, which can be particularly devastating to fields and for which growers have few alternatives. When applied against primary pests, chlorpyrifos also controls important secondary pests like craneflies, which feed on roots and underground rhizomes.
Onion
Value of the Crop
According to the National Onion Association, the annual value of the U.S. onion crop is nearly $1 billion at farmgate and $4-5 billion retail.
Where and How Much Is Grown
According to the National Onion Association, U.S. farmers plant approximately 142,000 acres and produce about six billion pounds of onions each year. Onions are grown in more than 20 states, with the top producing areas based on 2007 planted acres being Washington, Idaho-Eastern Oregon and California, followed by Texas, Georgia, New York and Colorado.
Why Chlorpyrifos Is Needed
Chlorpyrifos is currently one of only two treatment options for root maggots, an important pest of onions. Root maggots first attack germinating seedlings, feeding on the developing roots, and then attack the expanding onion bulb as it grows and matures. Bulbs sustaining maggot damage are predisposed to rot in storage.
Chlorpyrifos is also currently the only non-seed treatment option available in dry bulb onion production. Chlorpyrifos is typically used as an in-furrow directed spray or granule application made at planting or very early post-planting with one application per season. Nearly 70% of the use of chlorpyrifos for onion pests occurs for protection of dry bulb onions in Western states.
Onion growers also need chlorpyrifos as an alternative means of pest control for use in rotations with other products to prevent insect resistance, particularly because chlorpyrifos provides an additional mode of action. Although onion maggot has developed resistance to chlorpyrifos in some areas, without chlorpyrifos, development of resistance to cyromazine (the other pest control product available for onion pest control) would definitely proceed at an accelerated rate.
Peanuts
Value of the Crop
According to the American Peanut Council, peanuts are the 12th most valuable cash crop grown in the U.S., with an annual farm value of over $1 billion.
Where and How Much Is Grown
The 2008 U.S. peanut crop is the largest on record along with the highest average yield. Over 1.4 million acres were planted with an estimated production of five billion pounds. Georgia accounted for more than half the production with Alabama and Texas accounting for another 25% of the total crop. Other peanut producing states included Florida, North and South Carolina, Virginia and Oklahoma.
Why Chlorpyrifos Is Needed
Chlorpyrifos is one of the leading products used against soil insect pests feeding on developing peanut pods. In 2008, 18% of peanut acres were treated with chlorpyrifos, which is primarily used in peanuts as granular post-plant applications to control lesser cornstalk borer and southern corn rootworm. Lesser cornstalk borers attack pods, pegs, lateral stems and the plant crown at the soil line, especially during extended drought stress. In addition to direct injury, borer wounds make the plant vulnerable to fungal infections resulting in increased levels of white mold and aflatoxin.
Pome Fruits
Value of the Crop
- Apples – The U.S. is the world's second-largest producer of apples. About one out of every four apples harvested in the U.S. is exported. In terms of fruit production, only oranges and grapes have more committed U.S. acres. About 60% of the apples grown in the U.S. are sold as fresh fruit, with the rest being processed (juiced, canned, frozen or dried). Apples are the number one cash crop in Washington State.
- Pears – Total U.S. pear production in 2007 was valued at $365 million. About a third of the U.S. pear crop is exported, with about 60% sold domestically as fresh fruit and the rest being processed (primarily canned).
Where and How Much Is Grown
- Apples – Apples are grown commercially in 36 states. The top six apple-producing states are Washington, New York, Michigan, Pennsylvania, California, and Virginia.
- Pears – Total U.S. pear production in 2007 was about 881 thousand tons with about half of that being raised in Washington State. Pears are Oregon’s leading tree fruit crop and the second largest fruit crop in Washington.
Why Chlorpyrifos Is Needed
- Apples – Chlorpyrifos is only applied to apple tree branches prior to bloom, but the product is still one of the leading means of controlling apple pests. In 2007, chlorpyrifos was used in apple production on nearly 270,000 acres. In the Pacific Northwest, it is the preferred product for use against a variety of overwintering pests, such as oblique-banded and red-banded leafrollers, Pandemis leafrollers and San Jose scale. Pre-bloom control of these pests is critical for their overall in-season management.
- Pears – While not the primary product for controlling pests of pears, chlorpyrifos is used in some cases to control leafrollers (oblique-banded, Pandemis) and San Jose scale as a delayed dormant application especially in the Pacific Northwest.
Soybeans
Value 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.
Stone Fruits
Value of the Crop
U.S. stone fruit production includes cherries, peaches, plums and prunes with an annual farm gate value of $2.3 billion.
Where and How Much Is Grown
- Cherries – More than 135,000 acres of cherries are grown in the U.S., making it the world's second largest cherry-producing nation. Michigan and Washington are the largest cherry producing states, followed by New York, Utah, Wisconsin, Pennsylvania and Oregon. Michigan produces about 75% of the tart cherry crop, and Washington and Oregon account for about 65% of the sweet cherries produced.
- Peaches – Nearly 146,000 acres of peaches are grown in the U.S. California acres account for about half of the production followed by South Carolina and Georgia. Total farm gate value is approximately $540 million.
- Nectarines – Nectarines are a cultivar of peaches in that they are the same species. Nectarines differ from peaches because, due to a simple recessive gene, their fruit is smooth skinned rather than fuzzy. Although nectarines can be grown wherever peaches can be grown, California produces 96% of the U.S. nectarine crop, yielding 436 million pounds of nectarines annually valued at $114 million on approximately 35,000 acres.
- Plums – As the dominant grower of plums with over 131,000 acres in production, California produces more dried plums/prunes than the rest of the world combined. Plums are also grown in Idaho, Michigan, Oregon and Washington.
Why Chlorpyrifos Is Needed
- Cherries – Chlorpyrifos is among the top four products used against insect pests of cherries, accounting for about nine percent of treated acres in 2007, with the majority of use occurring in Washington and Michigan. Chlorpyrifos is the only insecticide registered for protecting cherries against plum borer and peachtree borer, two pests that seriously impact cherry production when left uncontrolled.
- Peaches – Chlorpyrifos is the fourth most used product for controlling pests of U.S. peaches. It is the most frequently used product for control of peach tree borer and lesser peach tree borer, both serious pests of peaches that feed on the growing inner bark of the trees and that can girdle trunks and limbs, making trees vulnerable to fungus and disease organisms that kill live tissue or decay heartwood.
Sugar Beets
Value of the Crop
About 60 percent of U.S. sugar output is derived from sugar beets, with sugar cane supplying the remainder. Sugar beet byproducts include beet pulp, sold for molasses and animal feed. New technology is also being pursued for use of sugar beets in ethanol production.
Where and How Much Is Grown
In 2008, sugar beets were grown on more than one million acres in the U.S. The Midwest states of Minnesota and Michigan accounted for more than 52% of the U.S. sugar beet crop. North Dakota was the second largest sugar beet producing state with 206,000 acres planted, followed by Idaho with nearly 131 000 acres.
Why Chlorpyrifos Is Needed
Chlorpyrifos is the third most frequently used product for control of sugar beet pests, and treated acres have increased from 2004 to 2007 from 15% to 21%. Four states – Minnesota, California, Idaho and North Dakota – account for 87% of treated acres. Chlorpyrifos has been used for decades as an integral part of sugar beet pest management programs because it is effective against a broad range of pests and can be used with standard agricultural equipment.
Two of the most important insect pests in sugar beets are root maggot and cutworm. Root maggot feeding damages roots, which wilts the plant, resulting in reduced yield tonnage, reduced beet sucrose content and in some cases even stand loss. If fungal diseases infest the wounds caused by feeding, losses are compounded. Cutworms feed by night just below the soil surface, wilting or killing beets, and large areas can be damaged overnight when infestation is serious. Chlorpyrifos is the second most widely used product for control of both these pests, and treatment also controls armyworm, grasshopper, Lygus plant bug and aphids.
Sweet Potatoes
According to the North Caroline Sweet Potato Association, in 2007, the cash value of the U.S. sweet potato crop was approximately $374 million.
Where and How Much Is Grown
Total U.S. sweet potato production has remained steady since 2004 at about 100,000 acres . In 2008, the top sweet potato producing states, based on the value of production, were North Carolina, California, Mississippi, Louisiana and Alabama.
Why Chlorpyrifos Is Needed
Chlorpyrifos provides effective control of wireworms, flea beetles and other important pests of sweet potatoes. The product has been the foundation for control in sweet potatoes for many years and is also an important tool in sweet potato integrated pest management plans. Market acceptance of insect-damaged sweet potatoes is very low, and even minor surface damage can drastically reduce marketability. Sweet potato growers have few alternatives to chlorpyrifos for effective control of these major sweet potato pests.
Tree Nuts
Value 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.
Pecan Nut Casebearer Damage - 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.
Wheat
Value of the Crop
Wheat is the main food grain produced in the U.S. Presently about half the nation's wheat is exported. Wheat ranks third, behind corn and soybeans, among U.S. field crops in both acres planted and gross farm receipts.
Where and How Much Is Grown
Kansas, North Dakota, Texas, Oklahoma, and Montana account for 60% of U.S. wheat acres planted.
Why Chlorpyrifos Is Needed
Because of its consistently high levels of control of aphids (including greenbug and Russian wheat aphid), and other major pests, chlorpyrifos has been the leading product used against U.S. wheat pests in four of the past five years. Aphids have explosive reproduction capabilities, and growers prefer chlorpyrifos for use against aphids because of its quick knockdown of these damaging pests.
1 Gianessi L. The Value of Insecticides in U.S. Crop Production. CropLife Foundation. March 2009. http://www.croplifefoundation.org/Insecticide_Benefits/Executive_Summary.pdf Accessed April 21, 2009.
2 Dow AgroSciences. Chlorpyrifos – North America. Chlorpyrifos Reregistration. http://www.dowagro.com/chlorp/na/rpa/rereg.htm. Accessed April 21, 2009.
3 United States Department of Agriculture. USDA Economics, Statistics and Market Information System (ESMIS). http://usda.mannlib.cornell.edu/MannUsda/homepage.do Accessed June, 2009.
