Sprayer calibration

Sprayer Calibration

Tuesday Jun 01, 2021

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.

Monitoring Adult Codling Moth

Saturday May 22, 2021

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

Saturday May 15, 2021

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

Saturday May 08, 2021

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.

Bt Applications for Leafrollers

Saturday May 08, 2021

Bacillus thuringiensis (Bt) is a bacterium that must be eaten by lepidopteran larvae (caterpillars) to be effective. Bt is a great material for leafroller control because it is specific and has little effect on natural enemies. However, it must be applied 2-3 times to be effective when leafroller populations are high. Experience has also shown that in the spring, the high temperatures need to be above 65°F for 3 or more days so that larvae have a chance to feed on it before sunlight breaks it down. DAS provides forecast temperatures for all stations in the "Weather Forecast" and in the "Show Data Grid" table so that you can decide whether or not to use Bt or other recommended chemicals.