Which Type of Apple Sunburn is in Your Orchard?

Thursday Jun 01, 2023

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

Monday May 22, 2023

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

Monday May 15, 2023

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

Monday May 08, 2023

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

Monday May 08, 2023

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.