23 November 2001

Star rating to help with thistle control

A NEW star rating system from Dow Agrosciences aims to help growers combat creeping thistle and prevent the weed developing resistance to key herbicides.

The main problem in deciding how to react to infestations is their patchiness, making overall spraying of light infestations uneconomic, said the firms Rene Pollak.

Creeping thistle has also developed resistance to some older herbicides like MCPA elsewhere in the world. With only three modes of action available among UK thistle weed-killers, the full range of control strategies needs considering, he advised.

The star system, taking into account crop type, thistle frequency and location, cultural and chemical control, anti-resistance strategy and spray timing allows users to assess the threat and adopt appropriate tactics. &#42