Q&As/Insects and Pests/Thrips
This year our “Peasgood Nonsuch” apple tree has been infected and I am not having much success with it. Starting at the lower leaves they have become a bronze/silver colour, gradually moving up the tree. It is now showing on the raspberries on the eastern side. Wind borne? We have sprayed with Target but have so little of it left and cannot buy more.
From your description it would appear that your heritage apple Peasgood Nonsuch has a severe infestation of thrips. These very small insects rapidly multiply in warm humid summers and attack numerous trees and shrubs.
It is critical that you are very thorough with garden hygiene over the next few months as this will help reduce future outbreaks. All pruning material from the apple and other infected plants should be burnt or removed from your property.
When pruning your apple tree in winter, ensure there is adequate air movement through the tree. Thrips breed most freely amongst heavy layered vegetation where they are protected from possible predators and the air is moist and humid.
A winter clean up spray of horticulture oil and or lime sulphur will help remove any traces of overwintering thrips.