Spray enhancers play an essential role in improving the biological performance of agrochemicals.
Broadly speaking spray enhancers can be broken down in to three categories: adjuvants (these encompass wetters, sticking agents, penetrants and drift retardants), water conditioners and auxiliary products, such as bout markers, anti-foaming agents and dyes.
While spray enhancers fulfil a range of functions, their contribution can be summarised as enhancing product efficacy to levels that would otherwise not be achieved without their use.
Most spray enhancers would be described as adjuvants. These are not classed as plant protection products. Instead, the Chemicals Regulatory Directorate (CRD) defines an adjuvant as: a substance other than water which is not in itself a pesticide but which enhances or is intended to enhance the effectiveness of the pesticide with which it is used.
Adjuvants boost performance in a variety of ways, these include:
- Improved leaf coverage of waxy/hairy targets and dense canopies through enhanced wetting
- Reduced drift through a reduction of fine droplets
- Optimal application timing even in catchy weather through improved sticking ability
- Improved deposition and leaf retention through enriched sticking and wetting
- Improved chemical uptake though surface penetrants, and
- Reduced pesticide lock-up through water acidification
Certain plant protection products will stipulate the use of a spray enhancer to achieve the desirable performance while others will advise their use under specific conditions.
Water conditioners, De Sangosse’s X-Change for example, contains a sequestering agent that prevents the cationic elements in herbicides, such as glyphosate and sulfonylureas, being locked up by hard water.