Sprayer Calibration

Monday Jun 01, 2026

While the WSU-DAS system focuses on using pest and disease phenology to properly time pesticide sprays, it is critical that the properly-timed sprays are applied correctly. Without proper coverage, sprays will not serve their intended purpose, and growers may waste material, labor, and money, without getting the anticipated control.

Spider Mite Control During the Summer

Monday Jun 01, 2026

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.

Which Type of Apple Sunburn is in Your Orchard?

Monday Jun 01, 2026

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).

Monitoring Adult Codling Moth

Friday May 22, 2026

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

Friday May 15, 2026

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.