Controlled Droplet Application

Controlled Droplet Application

The efficiencies of CDA technology

Most agrochemicals are applied as liquid sprays which are broken up and distributed over the target area.

The secret of efficient spraying lies in even and targeted liquid distribution. Uneven coverage of the target area is wasteful, costs money and results in unwanted and unnecessary contamination of the environment.

Another important factor for achieving the best biological results is the spray droplet size. For most spray applications there are particular droplet sizes which will be most effective. In pesticide application, for example, different pests present different targets depending on their size, location and behaviour, thus different spray droplet sizes will be most effective depending on application.

Pioneered by Micron, Controlled Droplet Application (CDA) produces only the optimum sizes of spray droplet for the particular application. This is achieved by specifically designed spinning disc rotary atomisers which break up the spray liquid very evenly, resulting in a narrow range of spray droplet sizes.

CDA application v Nozzle spraying

In contrast, most conventional spraying machines employ a hydraulic nozzle which involves breaking up spray liquid by squirting it under pressure through a hole. This application method is rather inefficient as it breaks up the spray liquid very unevenly and produces a very wide range of droplet sizes.

Very large and very small spray droplets are both wasteful – the large ones end up on the ground whereas the small ones drift wasting much of the spray and contaminating the environment. This inefficiency means that hydraulic nozzle sprayers have to use much more spray liquid than is actually necessary to do the job. To fetch, carry and spray this extra liquid costs time, effort and money for both the small farmer in the developing world carrying out most jobs manually or the large mechanised western farmer.

The waste and environmental contamination resulting from spraying pesticides through hydraulic nozzles is causing increasing world-wide concern. CDA offers a scientifically-proven solution that improves spraying efficiency, eliminates waste and safeguards the environment.

The efficiency of CDA enables the use of low and ultra-low volumes of spray liquid. This logistical advantage can be of critical importance in crop protection, allowing effective spraying programmes to be undertaken quickly in non-mechanised agriculture and greater spraying productivity in mechanised agriculture. Being able to apply pesticides accurately, quickly and cost – effectively when needed gives the opportunity of fully implementing Integrated Pest Management programmes, with reduced overall pesticide usage.

The Targets in Crop Protection

TargetOptimum Sizes of Spray droplet 
Flying Insect 10-50 micron spray droplets 
Insects on Surfaces 30-150 micron spray droplets 
Plant Diseases 30-150 micron spray droplets 
Weeds 100-300 micron spray droplets 


A review of work carried out relevant to the use of CDA for application of biological products.

CDA Biologicals