Technical Information & Links
Drift-reducing nozzles and their use in practice:
Drift-reducing nozzles are now commonplace and most spray operators will have at least one set available. Their challenge is to know which ones to buy, and when to use them.
Our key messages are:
The performance of drift-reducing nozzles will be product-dependent and therefore we cannot recommend overriding manufacturer’s guidance or label requirements.
The AHDB nozzle selection chart, although in need of updating, still provides the best generic guidance and advises that for applications to plants, a small-droplet (low drift reduction) AI nozzle will give better performance than a large droplet (high drift reduction) one.
Applications to soil will be unaffected by droplet size and therefore pre-emergence applications can be successfully undertaken with the highest drift reduction available
Where manufacturers have formulated products to be effective with nozzles that give high levels of drift reduction, and are willing to support their use, then go ahead!
When choosing a nozzle with a given level of drift reduction, make sure this can be achieved with a sensible pressure range (e.g. 1 – 3 bar) and at a boom height you can reliably achieve at the speed you intend to travel.
Links to useful information:
Information about Air Induction nozzles:
HGCA Project 317 – Defining the size of target for air-induction nozzles.
HGCA Project 408 - Spray behaviour and efficacy of herbicides and fungicides
applied to wheat at reduced volumes.
HGCA Project 526 - Distribution of spray applied to a cereal crop and the effect
of application parameters on penetration.