Adjuvants 

Adjuvants are substances that can be added to sprays to improve the spray’s performance. Those in agriculture, horticulture, nurseries and other commercial operators will be familiar with some adjuvants but should home gardeners also use such products?

Adjuvants are spray additives usually categorised by their mode of action as follows:

• Acidifiers – Lowers pH of spray to overcome the effects of hard water and aids penetration.
• Buffers – Stabilises pH.
• Crop oils – Softens plant waxy cuticle to aid absorption.
• De-foaming agents – Stops foaming in spray tanks.
• Drift retardants – Affects spray droplet size to reduce spray drift.
• Marker dyes – Reduce waste and ensures even coverage by making sprays visible on foliage.
• Penetrants – Assist in penetration of substance into leaves, roots and stems.
• Stickers – Increase adhesion of fine particles and substances to leaf surfaces and reduce washing effect of rain or irrigation.
• Surfactants – Improve wetting and spreading of products on leaf surfaces.
  • Non-ionic (no charge) – aid penetration.
  • Anionic (negatively charged)
  • Cationic (positively charged) – mostly used with herbicides.

Should You Use Them?

In the home garden adjuvants are rarely of use as Kiwicare pesticide products already contain the adjuvants that are needed. Indeed, adding adjuvants, unless they are specifically recommended, may be detrimental to the efficacy of a product, e.g. adding a surfactant wetter/spreader may not give better coverage and may cause increased runoff, reduce penetration and damage plants.

Do not use industrial or household products that are not formulated for the specific pesticide product as they might interfere with the pesticide performance and may not be registered.

Only use adjuvants approved and recommended for use with the pesticide and in the use proposed. E.g. Dye & Stick with Kiwicare Weed Weapon Extra Strength or LawnPro Turfclean.

Dye & Stick helps Kiwicare herbicides adhere to particularly water repellent leaves of weeds such as ivy, tradescantia, agapanthus and also shows where the spray has contacted, which helps when spraying in many situations including lawns when controlling broadleaf weeds.

David Brittain
Kiwicare