Apple, Codling Moth Control with Dimilin, 1991

Plots were located in a 10-yr-old orchard with under-tree sprinkler irrigation. The experimental design was a randomized complete block with 4 four-tree replicates. Dilute sprays were applied to runoff with a handgun sprayer operated at 200 psi and with an output rate of 3800 liters/ha. The date of first consistent CM catch as determined by pheromone traps placed in the block was 16 May. Cover sprays were timed using a temperature-driven CM model of development. First applications were timed to coincide with beginning of egg hatch. First applications of Dimilin + Guthion on 6 Jun were followed with Dimilin alone on 27 Jun and 19 Jul. Refer to the table for specific dates of application. Five fruit per tree and 5 fruit from the ground underneath each tree were sampled for CM damage (external stings + internal worms) by cutting fruit on 27 Jun, 19 Jul, and 8 Aug. Twenty fruit per tree and 20 fruit from the ground underneath each tree were sampled for CM damage on 30 Aug and 20 Sep. CM pressure was heavy.