A sprayer operator stands at the parts board with a tray of coloured tips and a decision to make every time the tank mix changes. The nozzle type decides whether the chemical lands in the crop, drifts into the ditch, or sits in a streak across half the field. This is the map of the three types that cover almost all agricultural spraying, and when each one is the right call.
The names on the tips — flat fan, cone, air-induction — describe the pattern, and the pattern decides where the droplets go. Everything else follows from that.
Flat Fan — The Broadcast Workhorse
The flat fan produces a thin, even sheet that lands as a uniform band across the boom. This is the default for broadcast herbicide application, where you want every part of the soil or early-season leaf surface to receive the same dose.
Its weakness is drift: a plain flat fan runs a fine spectrum, and on a breezy day that fine fraction leaves the field. The coarse or air-induction variants of the flat fan exist specifically to fix this while keeping the even band.
Cone Nozzles — Canopy Penetration
Hollow cone and full cone tips throw droplets in a circular pattern rather than a flat sheet, and they reach into the canopy rather than skimming the top. Fungicides and insecticides, where the target is the lower leaves and the stem, are the cone-nozzle jobs.
Hollow cone favours penetration with a lighter droplet load; full cone delivers a denser, coarser pattern useful where thorough wetting of the canopy matters more than reaching the deepest leaf. The trade against the flat fan is evenness of a broadcast band — cones are not broadcast tools.
Air Induction — Drift Control by Design
Air-induction (sometimes called Venturi) tips pull air into the liquid stream and break it into large, air-filled droplets. The coarse spectrum stays in the field even in a moderate breeze, which is why they are the standard recommendation for sensitive-adjacent applications and for any herbicide pass where drift is the headline risk.
The cost is coverage on a tiny target: very coarse droplets can bounce or roll off a small weed leaf rather than sticking. There is no free lunch — coarse controls drift, fine controls retention, and the choice depends on what you are spraying and where.
What the Colour Code Actually Tells You
Every tip carries a colour band, and the colour is not a brand statement — it is the flow rate at the reference pressure. A red tip always flows the same amount at 3 bar, regardless of manufacturer, which is what makes a tip drawer practical: the colour tells you the flow, the shape tells you the pattern, and the letters stamped on the body tell you the angle.
The practical implication is that “a new tip” is only meaningful if the colour and angle match the old one. Swapping a worn red flat fan for a shiny blue flat fan changes the application rate without a single setting being touched — the sprayer still reads the same pressure, but the output per hectare is different. This is the hidden variable behind a lot of “the field looked fine but the tank mix ran out early” complaints.
Pressure, Speed and Rate — Three Knobs, One Number
The litres per hectare actually reaching the crop is the product of tip flow, boom pressure and ground speed. Tip flow scales with the square root of pressure, so a small pressure rise is a modest flow rise — but ground speed halves the rate directly.
That is why the tip is only one-third of the equation. An operator who changes a tip without rechecking pressure, or who crawls through a wet patch and then speeds up on the dry, is spraying a different rate in different parts of the same field. Nozzle type picks the droplet behaviour; the flow, pressure and speed set the dose.
How Wear Turns a Good Tip Into a Bad One
The brass tip that was perfectly uniform in June has, by August, a slightly larger orifice — and that larger orifice flows more at the same pressure while the spray angle tightens. The result is a narrower, heavier band than the rate setting says, which is why fields develop a stripe pattern rather than a uniform tone.
Ceramic and hardened stainless tips hold their geometry far longer than brass, which is why they are the sensible buy for abrasive suspensions even at a higher unit price. The cheap tip that wears in a season costs more in wasted chemical than the expensive tip that does not.
Matching the Type to the Job
A single season usually runs all three. Early post-emergence herbicide over open ground is a flat fan or air-induction job. Fungicide into a closed canopy is a cone job. A breezy day flips the flat fan to its air-induction cousin.
The mistake is treating the tip drawer as one bin. Each mix — herbicide, fungicide, fertiliser, surfactant-heavy or water-only — has a type that suits it, and the operator who swaps types with the tank mix protects both the crop and the neighbour’s field.
How to Choose the Type
- Broadcast soil or early leaf herbicide — flat fan; switch to air-induction on breezy days or near sensitive areas.
- Fungicide or insecticide to the canopy — cone, for penetration to lower leaves.
- Drift-sensitive duty — air-induction, accepting slightly lower retention on small targets.
- Application rate and boom pressure — set the flow and pressure first, then pick the tip colour that delivers it for the chosen type.
- Wear discipline — tip wear changes the rate silently; measure output and replace on schedule regardless of which type you run.
The agricultural spray nozzles range covers the flat fan, cone and air-induction tips discussed here, with flow and drift-class data for each. If the duty sits outside the standard pattern table — unusual boom geometry, a particular drift requirement, or a chemical that needs a specific droplet band — send the details through the enquiry form and the selection can be worked out against your pressure and speed before you buy.
Frequently Asked Questions
Which nozzle type is best for herbicide? Flat fan for open-ground broadcast, air-induction where drift is the risk. Neither is “best” in all conditions — the mix and the wind decide.
Are cone nozzles good for herbicides? Poorly for broadcast work — they do not lay an even band. They are canopy tools for fungicide and insecticide.
Why use air-induction if it covers less well? Because coarse droplets stay in the field. On drift-sensitive passes that trade is worth more than perfect retention.
Do I need different tips through the season? Yes. Herbicide, fungicide and fertiliser duties want different types, and the operator who changes types with the tank mix protects efficacy and avoids drift complaints.