10.3 Application Methods and Placement

Selecting a method is a Core legal skill

40 CFR 171.103(c)(7) requires commercial applicators to select appropriate application methods, including all of the following:

• Methods used to apply various forms and formulations of pesticides.
• Knowledge of which method to use in a given situation, and that use of a fumigant, aerial application, sodium cyanide, or sodium fluoroacetate requires additional certification.
• How selection of method and use of a pesticide may result in proper use, unnecessary or ineffective use, and misuse.
• Prevention of drift and pesticide loss into the environment.

Equipment from Section 10.1 and nozzles from Section 10.2 are tools. This section is the decision: where the deposit should go, how it should get there, and which Oklahoma credential is even allowed to make that application.

Methods matched to formulation and target

Broadcast treats the entire area—hydraulic boom, rotary spreader, or a full airblast pass down an orchard row. Use it when the pest or weed is uniformly present and the label allows area-wide application. Broadcasting a crack-and-crevice insecticide across a restaurant dining room is the wrong method even if the active ingredient is labeled for food-handling areas in another use pattern.

Band treats a strip: over the seed row, along a fence, down a turf collar, or under pecan trees with a shielded boom. Even-fan tips or a physically shielded directed boom make a band. Banding can cut product use. It is ineffective if the pest lives between the bands and you pretended a band was a broadcast.

Directed sprays aim at the target and away from a crop, bloom, water, or hardscape. Examples include drop nozzles in corn, under-tree herbicide in a pecan grove, and spraying the base of a shrub instead of fogging the flower bed. Basal herbicide treatments wet the lower bark of brush so the product moves in woody tissue. They fail if you mist the canopy and call it basal, or if you treat only one side of a multi-stem clump the label says to wet thoroughly.

Spot treatments hit individual weeds, fire ant mounds, or pest harborages. Crack-and-crevice places a thin stream, foam, or dust into structural cracks where cockroaches and ants travel. Void treatments inject into wall, equipment, or furniture voids. Bait placement puts a measured bait in stations or at trails. Broadcasting a station-only bait, or putting gel bait on a greasy stove that will be wiped in an hour, is the wrong placement even if the product name matches the pest.

Soil incorporation mixes or waters a herbicide or soil insecticide into the soil so it reaches germinating weeds or soil insects and is less available to photodegradation or washoff. Leaving a soil-applied product on heavy wheat residue without a labeled incorporation or activating rainfall can be ineffective use. Seed treatment in Oklahoma is Category 4: pesticide is applied to seed in a treater designed for that job. Spraying seed in a truck bed with a field boom is not Category 4 practice and often is not labeled.

Chemigation is an application method only when the label lists that irrigation system (center pivot, drip, sprinkler, and so on). Unlabeled chemigation is misuse, even with perfect backflow hardware. Labeled chemigation still requires the backflow and interlock devices described in Section 10.1. A pivot that throws onto a neighbor's field or a creek is pesticide loss, not "irrigation overlap."

Placement relative to the target

Put the deposit where the pest, weed, or pathogen actually is. A contact insecticide fogged into the middle of a warehouse while German cockroaches remain in electrical voids is the wrong placement. Fire ant bait belongs where workers forage, not in a water-filled rut. A foliar fungicide that never reaches the lower pecan canopy because airblast volume was set for a dormant tree is ineffective use. Termiticide in Category 7B work must reach the soil-foundation interface that structural work requires; a 7A foundation spray that "sort of hits the dirt" is not a 7B substitute.

Formulation drives method. Granules do not become a foliar spray because you are in a hurry. A fumigant gas is not a substitute for a void aerosol. A systemic soil drench does not replace a labeled foliar spray if the pest is feeding on untreated new leaves and the product does not move that way in time.

Extra certification: fumigant, aerial, sodium cyanide, sodium fluoroacetate

Core knowledge includes this bright line from 40 CFR 171.103(c)(7)(ii): using a fumigant, making an aerial application, or using sodium cyanide or sodium fluoroacetate requires additional certification. Those uses are not covered by "I passed Core and 1A" or "I passed Core and 7A."

Oklahoma implements the same idea in its category list:

• Category 15 Aerial cannot stand alone. You need Core, at least one appropriate work category (for example agricultural plant if you will treat crops), and aerial. PSI's Oklahoma pesticide program states the aerial exam cannot be taken by itself. New aerial businesses also face FAA Part 137 aircraft rules at licensing; those aviation rules are not a substitute for pesticide certification.
• Category 7C Fumigation (liberated gas in a structure or storage area, including railcars and ships) requires Core, the 7C written exam, and a practical exam at OSU in Stillwater. ODAFF lists 7A, 7B, and 7C practicals as OSU Stillwater practicals; fumigation practicals are administered through OSU's stored-product research and education facilities. Practicals must be completed on ODAFF's timeline after the written exams (failure to finish the practical in time means retaking the category exam).
• Sodium cyanide (typically M-44 ejector devices) and sodium fluoroacetate (Compound 1080 livestock protection collars) fall under predatory-animal certification (Oklahoma 11B), not a general 7A, 1B, or 11A bird-and-vertebrate card. Core still expects you to know that those chemistries are extra-certification uses.

Soil fumigation and non-soil fumigation each have their own federal category competency standards. Do not treat a 7C structural/storage practical as a field soil-fumigation card, or the reverse, without checking the actual Oklahoma category you hold.

The 7A three-foot rule is not a nozzle setting

Oklahoma Category 7A General Pest covers pesticide application within and immediately adjacent to a structure (with listed exceptions for fumigation, wood-destroying organisms, birds, and predatory animals). "Immediately adjacent to a structure" means not farther than three (3) feet from the structure. That three-foot line is a site credential limit, not a nozzle specification and not a turf-gun range setting.

A fan tip or turf gun that can throw 25 feet does not expand 7A onto the rest of the lawn. Treating the whole yard is a different credential (typically 3A ornamental and turf), not a "bigger tip" decision. Core exams like this trap because it mixes Chapter 10 equipment knowledge with the legal site of use. Equipment reach is not certification reach.

Proper use, unnecessary use, and misuse

40 CFR 171.103(c)(7)(iii) asks you to see how method and product choice produce three different outcomes.

Proper use is a labeled product, at a labeled site, with a method that can actually reach the pest, applied only when the pest or the preventive need is real, with drift and runoff reasonably prevented. Example: a labeled boom herbicide on wheat at the labeled spray quality, with a level boom, matched tips, wind within label limits, and no spray over the creek at the field edge.

Unnecessary or ineffective use wastes product and can select for resistance without solving the problem. Examples: broadcasting a contact insecticide because it is already mixed; chemigating a product that will not move to the pest in that irrigation set; fogging for a bait-averse cockroach population living in voids; spraying pecans with airblast during a strong wind so most of the mix leaves the orchard; applying a soil preemergence product on a thick residue mat with no labeled incorporation or rain.

Misuse is use in a manner inconsistent with the label or with your certification: unlabeled chemigation; aerial application without aerial certification; fumigating a railcar on a 7A card; treating 40 feet of lawn on 7A because the gun reaches; mixing nozzle types so part of the field is overdosed; applying during conditions the label forbids; using 1080 or sodium cyanide without the predator-control credential. Misuse is not cured by good intentions or by "the boom was calibrated last season."

Preventing drift and pesticide loss

40 CFR 171.103(c)(7)(iv) pairs method selection with prevention of drift and pesticide loss. Equipment and method choices that reduce loss include:

• Coarser labeled spray quality when coverage still suffices; lowest effective boom height; shutting off boom ends over water, roads, and neighbor lines.
• Directed, banded, basal, spot, crack-and-crevice, void, or bait methods instead of a room-wide or field-wide broadcast when the pest is local.
• Hooded or shielded sprayers for under-tree or in-row work.
• Keeping granules off impervious surfaces that drain to storm sewers; not applying fire ant bait immediately before irrigation that will ruin the bait.
• Holding chemigation when a pivot will throw onto a neighbor or when injection would continue after the well pump fails—that is what check valves and interlocks are for.
• Refusing to spray in a temperature inversion or in gusts that carry fines off the target.
• Not treating dribbles from a leaking gun in a parking lot, or mix dumped in a ditch as "rinse," as housekeeping. Those are applications to the environment.

Oklahoma's Sensitive Crop Viewer exists because a legal product, a calibrated boom, and a bad method (fine spray, high boom, wrong wind, unlabeled chemigation) can still destroy a neighbor's crop. Method selection is how Core competency continues after the pump is running.