Monday Feb 10, 2020
Woolly apple aphid (WAA) has become more common over the past few years and is a quarantine threat for export to certain countries. WAA can be found feeding on the roots as well as occurring in the tree canopy where it can appear as a white cottony mass on pruning scars or shoots.
Tuesday Feb 04, 2020
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.
Tuesday Feb 04, 2020
Nearly 1,000 species of bees occur in the Pacific Northwest, but only a small number of species are useful in the pollination of orchard crops. Pesticide use and loss of appropriate nesting habitat have reduced the numbers of wild bee pollinators, leaving most of the pollination for commercial orchards dependent on honeybees. The success of honeybee pollination in tree fruits is affected by a number of factors, which in part can be manipulated by orchardists and beekeepers.
Saturday Feb 01, 2020
Mating disruption dispensers work by releasing synthetic pheromone which prevents or delays males from finding and mating with females. Therefore, dispensers need to be placed in your orchard before the first moths fly and mate. First moth flight (= biofix) occurs at around 175 DD. We recommend to place pheromone traps before first apple blossoms open or by 100 DD whichever comes first.
Thursday Jan 02, 2020
Dormant sprays are important for management of a wide range of pests including European red mite, woolly apple aphid, rosy and green apple aphids, and San Jose Scale. Most of these are easily controlled using a variety of materials, but if you are using oils, remember that good coverage is essential because they work by covering the egg stage and preventing respiration.