# Pesticide application: broadcast, band, spot treatment and marker dye

URL: https://leafwrit.com/ie/pesticide-application-methods/
Reviewed: 2026-10-29

**Pesticide application methods describe where and how a treatment reaches its target.** Broadcast spraying covers the whole area; band treatment covers strips; directed spraying places material away from crop foliage; patch and spot treatments restrict the area treated. Weed wiping uses contact with the applicator instead of spraying the whole sward.

Identify the target, intended placement and equipment, then check the exact crop, situation and use through [DAFM’s product searches](https://www.pcs.agriculture.gov.ie/products/).

## Compare the main types of pesticide application

The placement terms below describe different aspects of a job. A handheld sprayer, for example, names equipment; “spot treatment” describes the limited area being treated. Write both in the instruction so the contractor knows what you mean.

| Method | Where the treatment goes | Question to settle before planning |
| --- | --- | --- |
| Broadcast spraying | Across the whole target area. | Does the treatment decision concern the entire field? |
| Band application | Along defined strips, such as crop rows. | What width is actually treated and what remains outside the band? |
| Directed spraying | Towards selected weeds, stems or soil while avoiding crop foliage. | Which plant surfaces are targets and which must be avoided? |
| Patch treatment | Within selected parts of a field. | Are the patch boundaries clear to the operator? |
| Spot treatment | Onto small targets, potentially individual weeds. | Can the equipment identify and treat the intended target? |
| Weed wiping | Primarily onto target plants contacted by the applicator. | Do the product and applicator match the intended grassland job? |

Check the selected method against the Irish authorisation of the exact formulation.

## Broadcast spraying: uniform placement across a field

Conventional spraying aims for even application across a field. A nozzle delivers droplets at a set pressure towards the plant, weed or soil. Discuss distribution, forward speed and pressure even when the product and total field area are already known.

Tell the adviser what surface needs treatment. A soil target, a weed leaf and crop foliage are different descriptions of the job. Include the crop’s condition, target distribution and machine available, and ask for an instruction that connects those details with the chosen product.

For equipment procurement, use the [sprayer-selection guide](/ie/agricultural-sprayer-selection/). For output and batch arithmetic, continue to [calibration and tank calculations](/ie/spray-tank-mix-calculator/). Choose the application pattern before preparing a load calculation.

## Band spraying: distinguish field area from treated strips

Band application leaves part of the field surface untreated. Calculate the treated strips separately from the spaces between rows. Apply the authorised rate on its stated area basis, then calculate the quantity for the treated bands.

Prepare the row spacing, intended band width and length of work for the adviser, and keep each measurement labelled. Ask whether a quoted quantity refers to the whole field, the treated band area or a different basis, and resolve that before multiplying a rate by hectares.

Do not reduce a product rate merely because the treatment covers less ground. Establish the correct authorised inputs and their area basis, then calculate the job quantity. Band-area calculations use US extension guidance; Irish product conditions govern the treatment.

## Keep the pack concentration separate from the field rate

An instruction can express a rate as active ingredient, acid equivalent or commercial product per treated area. Identify the rate basis and calculate the corresponding amount of the marketed formulation.

Write units beside every quantity. Separate millilitres from litres, product from water, and container capacity from the batch being prepared. Keep the original instruction with the calculation so another operator can follow the same basis.

## Directed and foliar herbicide application

Directed spraying describes placement that avoids crop foliage while reaching a selected target. Foliar application describes treatment reaching leaves. Contact herbicides act differently from herbicides transported within the plant. Check the formulation's coverage requirement when planning foliar application.

When requesting an instruction, describe the weed and crop positions together. Supply photographs showing the target among the crop, not just a close-up of an isolated leaf, and name any crop parts that must be avoided.

For a fungicide or insecticide, describe the target and crop, then check that product’s requirements. Use the [liquid-fertiliser nozzle guide](/ie/liquid-fertiliser-nozzles/) for fertiliser equipment questions.

## Patch and spot spraying: keep the untreated area visible

Patch spraying treats selected field areas; spot spraying targets smaller areas, potentially a single weed. Variable rate application is a different concept: the rate changes in response to measured variation. A machine can combine these functions, but the terms are not interchangeable.

Mark the proposed treatment boundary on the operator’s map and explain how to find the patches. Agree what to do if weed distribution differs on arrival, and record the boundary actually treated alongside the original plan.

Map problem areas for later targeted work, including hand-roguing or spot spraying. The same map can support a decision to remove individual weeds by hand rather than commission a chemical treatment.

An untreated patch, an intentionally missed area and an equipment fault are different observations. Note which one occurred when reviewing the work, and avoid labelling the whole field “sprayed” if that hides where the product actually went.

## Weed wiping, wick and roller applicators

A weed-wiping enquiry concerns contact with target plants. Tractor- or quad-mounted weed wipers apply product primarily to plants contacted by the applicator. This differs from broadcasting spray across the sward.

Before hiring equipment, ask for its make, model and applicator description alongside the full pesticide identity. Whether you are considering a wicking, roller or foam herbicide applicator, ask how the particular machine delivers material.

For MCPA and rushes, go to the [MCPA product and rush-control guide](/ie/mcpa-herbicide-ireland/). Settle the named product and application method together; a dose taken from a boom-spraying plan is not a ready-made recipe for a different applicator.

## Handheld pesticide application: describe the working pattern

“Handheld” identifies the arrangement used by the operator. It does not specify whether the plan is spot, band or directed treatment. Include the placement description when commissioning work rather than ordering only “a knapsack spray.”

Show the operator the target boundaries and the crop or vegetation to keep. Discuss access, obstructions and the locations that should remain untreated.

Use the [PPE and assessment guide](/ie/pesticide-ppe-risk-assessment/) to prepare handling controls.

## Smart spraying still needs a decision about the target

Precision spraying needs sensing, a researched response and application technology capable of delivering it. Check who turns the weed map into a treatment plan.

Ask a contractor what the sensor identifies, how the treatment decision is made and which machine output will be supplied afterwards. Ask for an explanation of the treatment map, including any sections deliberately left untreated, and compare it with what you see in the field.

Check sprayer setup, nozzle selection and water quality for the proposed treatment. Bring those practical inputs to the planning conversation instead of assuming that a technology name settles them.

## Herbicide marker dye: define what the colour should show

Explain whether the problem is seeing treated plants, marking a trial strip or reviewing an operator’s coverage. Kendon marker dye colours the spray deposit to make coverage visible. For a technical measurement of pesticide deposition or spray quality, ask the equipment specialist which assessment method to use.

For relief staff, explain how the mark will be interpreted. Do not let colour alone become the only instruction identifying where a pesticide was applied.

## Identify the complete dye product

Obtain the marketed name, manufacturer, intended-use instructions and safety information. Distinguish a marker dye from a surfactant, wetter or another additive even if a shop groups them under one heading.

Give the supplier the exact herbicide, formulation and application method and ask about compatibility for that combination. The Kendon marker is intended for liquid and powder herbicide formulations; confirm compatibility with the exact herbicide proposed.

Save the supplier’s reply with the proposal. If the dye or herbicide changes, ask again about the new combination.

## Read the pesticide and additive instructions together

Check mixture compatibility and whether each product retains its efficacy and safety. Keep those questions separate from whether the dye produces a clearly visible colour.

Use the [tank-mix compatibility guide](/ie/tank-mix-compatibility/) to prepare the question, and ask for written mixing instructions for the formulation and equipment where needed.

Keep the current documents beside the work instruction, with a note of who approved the combination and which conditions the answer covers.

## Preserve calibration and dose measurements

Calibrate the equipment and check its output regularly. A darker mark does not demonstrate the amount of herbicide delivered.

Record the product and water quantities and the calibrated machine setup, and list the dye and herbicide quantities separately. Use the [spray-tank calculation guide](/ie/spray-tank-mix-calculator/) for the arithmetic.

If the marker appears uneven, check output first and tell the equipment adviser about the nozzle, pressure, movement and target before changing the herbicide dose.

## Next step

Mark the treated bands, patches or individual targets before preparing the [tank calculation](/ie/spray-tank-mix-calculator/).