How We Use Pesticides in Agriculture

How We Use Pesticides in Agriculture

You’ve heard, “The dose makes the poison.” But, do you know the saying’s origin? As we dive into the topic of pesticide use in agriculture, it’s an appropriate time to brush up on the basics. So, I reached out to a cadre of experts from the University of Arizona and the Arizona Department of Agriculture.

By the end of a month-long research effort, I concluded that agriculture has the pesticide use thing down. Consumers, not so much.

And about the famous dosage use saying: Swiss physician, alchemist and astrologer of the German Renaissance (1493-1541), Paracelsus, is known to have said, “All things are poison and nothing is without poison; only the dose makes a thing not a poison.”

Arizona Farm Bureau is commited to helping Arizona families realize that most pesticide practices, through integrated pest management, involve mechanical and cultural methods, not chemical. Photo courtesy of Yuma farmer Jonathan Dinsmore.

Arizona Agriculture: Explain the toxicology maxim.

The “A” Team : “The dose makes the poison” maxim relies on the finding that all chemicals, even water and oxygen, can be toxic if too much is consumed or absorbed. And, for a consumer-friendly understanding of what a pesticide is, here’s a good definition to keep in mind: a pesticide is any substance or technology that is used to kill, manage or repel pests.

Arizona Agriculture: So then, if we’re going to focus on pests, what types of pests are we talking about?

The “A” Team : Don’t think just bugs. A pest is any living thing, whether animal, plant or fungus/bacteria, that damages or interferes with human interests, including agriculture. Pests may harm crops and livestock that we rely upon for food. They may damage our garden and landscape plants, our structures, disrupt the ecological balance in natural areas, even spread human diseases. Scientists also suggest that the use of the term “pest” may be subjective, as an organism can be a pest in one setting but beneficial, domesticated or acceptable in another.

o   Insects

o   Mites (these are creature-like insects but have soft bodies and four pairs of legs)

o   Rodents and scorpions

o   Other mammals (like javelina, wild boar, deer, squirrels and other furry friends that can cause crop damage)

o   Birds

o   Unwanted plants (that appear and interfere in crop areas, otherwise known as weeds)

o   Disease

Arizona Agriculture: What type of pest damage to agriculture are we talking about?

The “A” Team : Several types of pests reduce the yield and quality of agriculture crops, which translates into production losses and less food and fiber availability in the supply chain.

Arizona Agriculture: Describe methods of pest control, especially non-chemical, since most don’t realize a type of pest control even involves when we plant and harvest. And, these are methods used in conventional and organic farming.

The “A” Team : Broadly, there are two types of pest control: preventative and curative. Preventative measures are used before the attack of the pest and curative measures are used to control the pest after they appear and during their initial attack. Spanning across preventative and curative measures are several methods of pest control.

o   Mechanical/Physical: physical removal of pests, removal of weedy plants such as hand-hoeing, trapping pests, netting, using high- or low-temperature extremes to impact pests.

o   Cultural: crop rotation, deep ploughing, and clean cultivation, optimal use of fertilizers and water to encourage crop vigor and health, growing pest resistant crop varieties, timely planting and harvesting to avert pest growth cycles

o   Chemical: appropriate timely applications of safe and selective organic and synthetic chemicals.

o   Biological: several pests may be controlled to a certain degree by naturally occurring predators, parasites and diseases. We may rely on beneficial organisms already in nature, or may release them into the crop environment.

o   Plant quarantine : control of movement, distribution and spread of pests and infested commodities by state and federal regulations.

Arizona Agriculture: Describe Integrated Pest Management and what it means to consumers.

The “A” Team : Integrated Pest Management, or IPM, is a knowledge and ecosystem-based strategy that focuses on long-term sustained prevention or management of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties. Pesticides are used only after monitoring and established guidelines indicate they are needed to control pests to prevent economic losses. Treatments are made with the goal of removing only the target organism. Pest control materials are selected and applied in a manner that minimizes risks to human health, beneficial and non-target organisms, and the environment. Formal IPM programs were established in the western United States in the early 1960s. Additionally, The American Cooperative Extension Service (CES) plays a key role in helping farmers to use IPM effectively throughout the United States.

IPM helps ensure production of abundant, high-quality food and fiber in a manner that is environmentally and economically sound. According to the EPA, “Many, if not most, U.S. agricultural growers identify” with some type of IPM program.

Arizona Agriculture: Explain tolerance levels a bit more.

The “A” Team : Remember “the dose makes the poison.” To set the tolerance level, the Environmental Protection Agency (EPA) makes a safety finding that the pesticide can be used with “reasonable certainty of no harm.” To make this finding, EPA considers the human and environmental safety testing to assure non-carcinogenicity, teratogenicity [an agent that can disturb the development of an embryo or fetus], mutagenicity [an agent that changes the genetic material of an organism, often used in organic plant development], acute, chronic, dermal, oral, inhalation, risks, how much of the pesticide is applied and how often, and how much of the pesticide (i.e., the residue) remains in or on food by the time it is marketed. EPA ensures that the tolerance selected will be safe. EPA’s tolerance levels apply to food grown in the U.S. and imported food.

Consider Bee Colony Protection: Through a farmer or rancher’s IPM program on his or her own farm or ranch, they use a variety of methods to protect bees and other pollinators, according to the National Pesticide Information Center.

o   They apply pesticides when pollinators are inactive. For example, they spray in the evening, after bees have returned to their hives, allowing residues to dry overnight.

o   Label directions are strictly and carefully adhered to when using a pesticide product including paying attention to the “environmental Hazards” section of the label.

o   Apply the pesticide close to the target pest to minimize drift.

o   Apply pesticide using methods that are harmless to pollinators.

Arizona Agriculture: But still, consumers are going to ask, “Why pesticides?”

The “A” Team : On average, 35% of potential crop yield is lost to pre-harvest pests worldwide. Pesticides continue to be the most efficient and effective way to control pest damage, thereby preventing food waste. We need pesticides to help ensure an adequate global food supply.

Arizona Agriculture: How are we protected from inappropriate chemical application? Does a chemical approval process exist?

The “A” Team : The Environmental Protection Agency regulates the use of pesticides, continually evaluating them for effectiveness and assessing any potential risks to people and the environment. By using pesticides as directed by the label, farmers, homeowners and other pesticide users reduce any potential risks and maximize the benefits of effective pest control. 

Any substance intended for the control of pests (intended to destroy, repel, prevent, or mitigate) must be registered with the EPA before it can enter the stream of commerce or be used on our food and fiber.

Arizona Agriculture: How are pesticides registered?

The “A” Team : There are two main pieces of legislation governing that process: The Federal Insecticide, Fungicide, and Rodenticide Act (FIRFA) and the Federal Food, Drug, and Cosmetic Act. The process is scientific, legal, and administrative:

o   Scientific : Studies are undertaken to determine the effect of the chemical on humans, environment, and other untargeted organisms. No pesticide can receive an EPA registration unless EPA determines that use of the product will not cause unreasonable adverse effects to humans or the environment when applied according to the instructions and restrictions on the label.

o   Legal : Before a product can be sold, the label must be approved by EPA. The label includes instructions, dosage, toxicity, warnings and more. Failure to follow label instructions is normally a violation of federal law. Moreover, the label is considered a legal document – it can be evidence in a court case, for instance.

o   Administrative : Proposals to register or re-register products are published on the Federal Register for public comments. Each comment is taken into consideration, giving the public an opportunity to express its opinions and concerns about use of the product

Registrations are reviewed every 15 years to determine the aggregate effects of exposure, whether vulnerable populations (infants, children, the elderly) have increased susceptibility to exposure, and whether there are estrogen or endocrine-disruption effects.

Arizona Agriculture: Are there other rules regarding how pesticides are used or applied?

The “A” Team: Yes! Developed by the EPA, the Worker Protection Standard (WPS) sets forth mandatory guidelines farms must follow when using chemical pesticides. These standards are meant to make pesticide use as safe as possible for those who are applying the product and those who are in and around the area of application.

The WPS requires handlers and workers be given adequate information, including safety training, access to labeling information, and notification of pesticide-treated areas. It sets forth rules to keep people out of the direct path of pesticide application, including requiring applicators be provided proper personal protective equipment and that people are kept out of areas under a restricted-entry interval (every product has a specified re-entry period, which is the time that must pass between application and human re-entry into the area of application). The WPS also helps mitigate improper pesticide use through access to decontamination supplies, water for washing, soap and towels, and emergency assistance including transportation to medical facilities.

Arizona Agriculture: Who enforces the rules regarding pesticide use?

The “A” Team : Generally, States are tasked with the primary responsibility for monitoring compliance with/enforcing illegal pesticide use, including failure to comply with Federal Regulations in Arizona, the Arizona Department of Agriculture is in charge of regulating the use, disposal, and storage of pesticides.

Consumers have the right to understand how agriculture uses pesticides. More importantly, they have the right to know how effectively and judiciously we use pesticides. This is a start. 

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