§ Mr. Ron Daviesasked the Secretary of State for Scotland by what form of monitoring the Forestry Commission ascertains that aerial pesticide spraying carried out on its behalf has been carried out effectively on, and only on, the areas prescribed for spraying.
§ Mr. John MacKayThe Forestry Commission monitors aerial applications of insecticides by making it a requirement for the contractors to have an electronic track guidance system and to provide a print out of the track flown. Contractors are also required to use a droplet size which maximises deposition on the target foliage and the larvae feeding on it. Advice on the latter is obtained from the Cranfield Institute of Technology. Assessments of the target pest population shortly before and after spraying are made to determine the effectiveness of application.
The effectiveness of herbicide spraying is assessed by plotting the resultant kill of herbage. This has shown application to be very precise.