Deposition and droplet spectrum

Why Danfoil can deliver small droplets - with control and efficient penetration

The most important thing in one sentence

With Danfoil's spray technology, droplet size and droplet spectrum are primarily controlled by air pressure – not by water volume – so you can focus on crop coverage and drift control via the right air setting for the task.

Why "small droplets" are usually a problem – and why they don't have to be

Small droplets are attractive because they provide more uniform coverage and better deposition on the leaf. The challenge with conventional spray technology is that the finest droplets can be difficult to control and are more easily affected by wind. In Danfoil's system, the droplets are energized by the airflow, which helps them reach their target and penetrate the crop.

Rule of thumb

Air pressure = droplet size (and deposition/penetration) • Water volume = concentration & capacity (but does not change the droplet spectrum when the air pressure is kept constant).

The droplet spectrum depends on the air pressure – not the water volume

The compendium describes that the droplet spectrum from the Eurofoil® atomizer is, in practice, independent of the water volume (within normal working ranges) as long as the air pressure remains unchanged. This means that you can choose a water volume that suits the task and conditions without "ruining" the droplet spectrum – it is the air setting that makes the difference.

What happens when you change the air pressure?

Lower air pressure → coarser droplets and lower risk of drift (typically relevant for bare soil/low crops and "difficult" wind conditions).
Higher air pressure → finer droplets and better coverage/deposition, while the airflow helps penetration in denser crops.

The point is not "as much air as possible"—but the right amount of air for the task, so that the crop is moved easily without being "trampled down."

Documentation in the compendium: water-sensitive paper in the crop

The compendium describes experiments with water-sensitive paper placed at the top, middle, bottom, and on the ground in a crop. The experiments clearly show that changes in air pressure cause significant changes in droplet size and the amount of small droplets—and that the droplets are deposited throughout the crop when the setting is correct.

Practical takeaway

When you want to improve deposition and penetration: start with the air setting. Higher water volume is not a shortcut to better deposition if the air setting does not match the task.

How to use this in practice

1) Look at the crop and growth stage

Air pressure must be adjusted according to the height, density, and development of the crop. Denser crops often require more energy/air to ensure penetration and coverage at both the top and bottom.

2) Look at the wind and direction

Headwinds can reduce the throw length, so boom height and air setting should be adjusted. The right combination is about keeping drift down and still hitting the target effectively.

3) Keep track of the "balance"

Too low air pressure → risk of insufficient penetration in dense crops.
Too high air pressure → the crop may "close," and you lose effect + may increase the risk of drift.

The goal is an air pressure that causes the crop to move slightly—so that the droplets are "worked into" the crop.

If you want to delve deeper into the specific technology behind the system, start here: