2017 Crop Protection Guide for Tree Fruits in Washington

General Recommendations

Thursday, January 18, 2018

Chemical Rates

The chemical rates listed in the tables are based on dilute sprays for relatively large trees. See General Recommendations. Adjust per-acre rates according to density and severity of the pest problem. In determining rates and proper timing consider effect on beneficial species.

For dilute application, the volume of water applied per acre may be adjusted according to tree size and density of foliage to the gallonage when fruit and foliage is fully wetted to the point where drip or runoff is occurring throughout the tree. Gallons per acre will vary depending on tree stage and size. For concentrate application, generally it is simpler and more desirable to adjust the rate of chemical per tank or per acre than to vary the gallonage of water per acre. Make only minor adjustments in per-acre rates by altering ground speed. Ground speeds should remain within the range that gives optimum spray coverage. Do not alter ground speeds after calibration when using power-take-off sprayers. Slower application speed generally improves spray coverage. Applying sprays at excessive speed is the most common cause of poor coverage. Improved coverage enhances effect of the sprayed product.

Chemical rates less than those shown may be used in certain instances. Examples of situations in which lower rates may be desirable include dormant oil sprays on young orchards, certain growth regulators, certain miticide applications where predators are a major controlling factor, and some nutritional sprays.

Growers must carefully follow all restrictions on maximum rates on the label.

Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us