Also called ‘wilters’ or knockdown’. Contact herbicides are absorbed through the green organs on which they land, stay localised, and destroy those parts. The effect is only temporary in plants with well-established root systems, such as perennials. They are broken down in the soil almost immediately in some cases.

Contacts approved in the UK:

• Oxadiazon (RONSTAR)
• Glufosinate-ammonium (CHALLENGE)
• Paraquat (GRAMOXONE)