Which Type of Apple Sunburn is in Your Orchard?

Sunday Jun 01, 2025

Sunburn browning is the most prevalent type of sunburn, and is caused by high fruit surface temperatures (FST) and ultraviolet radiation. The FST required to induce sunburn browning varies by cultivar, but is in the range of 113 to 120 °F (45 to 49 °C).

Spider Mite Control During the Summer

Sunday Jun 01, 2025

There are currently lots of options to control spider mites in orchards. However, preventing outbreaks by avoiding pesticides toxic to predatory mites and their alternative prey is always first choice. If uncontrolled, spider mites can go through a single generation in 7-10 days during summer and increase their numbers exponentially. Monitoring helps to follow spider mite population growth and to intervene when necessary.

Monitoring Adult Codling Moth

Thursday May 22, 2025

Adult codling moth (CM) are monitored with traps baited with either CM pheromones or a mixture of pheromones and an attractant (Combo D/A lure). Pheromone traps should be placed in the upper 1/3 of the tree canopy before first apple blossoms open or by 100 DD since January 1 whichever comes first. If you are not using mating disruption...

Ways to Reduce Drift

Thursday May 15, 2025

Spray drift is one of the most important issues facing pesticide applicators. Movement to off-site locations can be caused by wind, poor calibration/adjustment, and operator error.

Use Pesticides Wisely to Avoid Resistance

Thursday May 08, 2025

Repeated use of pesticides with the same mode-of-action used in the orchard can accelerate the development of insecticide resistance. WSU recommends that when you choose insecticides, keep track of which ones are being used so that you alternate materials with the different modes-of-action (shown in DAS) between generations.