Kaolinite clay: a new method of control using a protective mineral barrier against the peach aphid, Myzus persicae Sulz

The green aphid, Myzus persicae Sulzer, is a major pest of peach trees. Trials have been conducted by the Ctifl since 2005 to assess the effectiveness of a product based on kaolinite clay, Surround® WP, depending on the time of application, in an orchard managed either organically or under integrated pest management, thereby allowing a comparison with the use of chemical aphicides. The clay can be applied either at leaf fall to disrupt egg-laying, or in spring to prevent the establishment of queen aphids. Clay applied in autumn reduces winter egg-laying by around 50 per cent. In spring, Surround® alone, when applied in autumn, is not sufficient to control aphid outbreaks, but it can form part of an integrated pest management strategy, combined with the application of mineral oils in late winter.