Recommendation - pre-planting treatments should be applied to container-grown plants using a mechanical spray system to isolate operators from the treatment and ensure consistency of treatment. The mix should contain 0.4% alpha-cypermethrin.
Container-grown plants are also vulnerable to damage by Hylobius abietis for the two years after planting. Unlike bare-rooted plants, they cannot be treated using the Electrodyn Sprayer Conveyor (ESC) and therefore a mechanical spray system for container grown plants is the recommended method of protecting plants during the first growing season. The Pesticide Safety Directorate (PSD) has recently approved the use of Alphaguard 100 EC containing alpha-cypermethrin for the treatment of plants after planting. Spraying with 0.4% alpha-cypermethrin has been shown to protect plants during the whole of the first growing season. It is essential that treated plants are allowed to dry under cover to ensure that the insecticide deposit is weather fast. This is also required before the plants can be handled safely for dispatch.