No abstract

Each treatment was randomly applied to 5 tagged twigs on each of 10 mature ‘Empire’ trees. These twigs had been previously examined for presence of ERM eggs at the node between 1989/1990 growth. Applications of Ortho Volck oil were applied to drip to each twig using a backpack sprayer. Fall treatments were applied 1 Nov 1990. Spring application was applied 14 Apr 1991. All twigs were removed from the orchard on 17 Apr and brought to the laboratory where they were cut into 5 cm pieces including the node. Cut twig pieces were placed in incubation chambers for egg hatch. Chambers consisted of 9.5 liter plastic freezer containers fitted with an elevated plexiglass platform on which each twig was affixed upright on a nail. Water was placed in the bottom of the container for humidity.