MD Pesticide Applicator key terms

A pesticide classified by EPA as available only to certified applicators or to people working under their direct supervision, because it poses elevated risk to people or the environment. In Maryland, only certified applicators may buy, use, or supervise its use.

A person who has passed the required Maryland examinations and holds valid certification, allowing them to apply restricted-use pesticides or supervise their use in the categories covered by that certification.

The written, printed, or graphic material attached to or included with a pesticide container. It carries legally binding directions, warnings, and use restrictions, and following it is mandatory under federal and state law.

A word printed on the label - DANGER, WARNING, or CAUTION - that reflects the product's acute toxicity. DANGER indicates the greatest hazard, WARNING moderate, and CAUTION slight, with corresponding precautionary statements required.

The dose of a pesticide that kills half of a test group of animals under stated conditions, usually expressed in milligrams per kilogram of body weight. A lower LD50 means greater acute toxicity.

The minimum number of days the label requires between the final pesticide application and harvest of the crop, so that residues at harvest stay within the legal tolerance for that commodity.

The period immediately following an application during which the label prohibits workers from entering the treated area without required protective equipment, reducing exposure while residues remain hazardous.

The maximum pesticide residue level legally permitted in or on a raw agricultural commodity, set by EPA. Food containing residues above its tolerance is considered adulterated and cannot be legally sold.

The gloves, coveralls, boots, respirator, eyewear, and other gear the label specifies for handling or applying a product. It must be worn as directed and kept clean, intact, and properly fitted.

Off-target movement of pesticide droplets, dust, or vapor away from the application site by air. Drift can injure sensitive plants, expose people, contaminate water, and violate the product's label directions.

An inherited ability of a pest population to survive a pesticide rate that would normally control it. It develops most quickly when the same mode of action is used repeatedly against a reproducing population.

A decision-making approach that combines pest monitoring, action thresholds, and multiple tactics - cultural, biological, mechanical, and chemical - to manage pests while minimizing risk to people and the environment.

The specific way a pesticide kills or suppresses a pest, such as by disrupting a nerve receptor, an enzyme, or a growth process. Rotating and combining modes of action slows the development of resistance.

A substance added to a spray mixture to improve how the pesticide performs, such as a surfactant that helps droplets spread and adhere to leaf surfaces or an oil that slows evaporation.

A procedure for emptying pesticide containers: fill the container about one-quarter full, close it, swirl, and drain into the spray tank, repeating three times so the rinsate is used rather than dumped.

The pest population level at which the cost of control equals the value of the crop damage prevented. Treating at or above this level is economically justified; below it, treatment usually loses money.

A herbicide applied to the soil before weeds emerge to prevent seedlings from becoming established. It usually requires rainfall, irrigation, or mechanical incorporation to move into the weed germination zone.

Applying pesticide only to infested patches or individual plants instead of treating the whole site, which cuts product use, cost, and exposure. It is common in turf, ornamental, and right-of-way programs.

Pouring or injecting a pesticide solution into the soil around a plant's root zone so the roots absorb it. This method is used mainly with systemic products for insects, nematodes, or root diseases.

Injury to desirable plants caused by a pesticide, such as leaf burn, yellowing, stunting, or distortion. It can result from overdose, tank contamination, drift, or use on a sensitive cultivar.

A product that is absorbed by the plant and moved through its tissues, allowing it to control pests that feed where the spray did not reach. Systemic activity also affects insects feeding on new growth.

A corridor such as a road, railroad, utility line, or fence line where vegetation must be managed for safety and access. Pesticides used there must be labeled for that specific site type.

Applying a herbicide mixed in oil to the lower portion of a woody stem - typically the bottom 12 to 18 inches - so it penetrates the bark and kills the stem without cutting it down.

Applying herbicide to the freshly cut surface or the exposed cambium ring of a stump to prevent resprouting. Prompt treatment, before the wood seals, improves control of woody species.

A herbicide that suppresses or kills certain plant species while leaving others relatively unharmed at the labeled rate. Selectivity allows weeds to be controlled where desirable vegetation must be preserved.

A product registered and labeled for use in or around water, such as for aquatic weeds, algae, or mosquito larvae. Only products bearing the specific aquatic site on the label may be used there.

A pesticide used to kill or suppress algae in lakes, ponds, and other water bodies. Products must be labeled for aquatic use, and treating very dense growth at once can cause oxygen loss that harms fish.

An organism, such as a mosquito, tick, or flea, that transmits a disease-causing organism from one host to another. Public health pesticide programs are organized around controlling these carriers.

A pesticide that kills the immature aquatic stage of an insect such as a mosquito, applied to breeding water before adults emerge. It is usually used as part of a broader mosquito control program.

Applying a very small amount of concentrated insecticide as extremely fine droplets, often by truck, aircraft, or fogging equipment, to kill adult mosquitoes and other flying public health pests.

A tamper-resistant container holding rodenticide or insecticide bait that keeps the toxicant away from children, pets, and non-target wildlife, while pests enter to feed on the formulation.

A precise application of insecticide into narrow gaps, joints, and hidden voids where pests harbor, made at low pressure with a directed nozzle so exposure to people and surfaces is minimized.

A pesticide applied to soil, wood, or building components to prevent or control termites. Soil-applied products must be placed at the labeled rate and depth to create a continuous treated barrier.

Forcing a wood preservative deep into wood under vacuum and pressure inside a closed cylinder, so the chemical penetrates beyond the surface and protects the wood much longer than a surface application.

A pesticide applied to wood to protect it from decay fungi, insects, and marine borers. The label specifies which treating methods, wood products, and exposure conditions the product may be used for.

A pesticide that exists as a gas or vapor at the temperature and pressure of use and penetrates enclosed spaces or commodities to kill pests. Fumigants require sealing, monitoring, and careful aeration afterward.

A written, site-specific plan for a fumigation job covering sealing, dosage calculation, monitoring, safety, notification, and aeration. Many fumigant labels require the plan before the application begins.

Applying pesticides from a fixed-wing aircraft or helicopter. It demands careful control of droplet size, wind, buffer zones, and notification, plus pilot certification, to keep the product on target.

Applying a pesticide to seeds before planting to protect germinating seeds and young seedlings from soil-borne insects and diseases. Treated seed must be labeled and must never be used as food or feed.