Glossary
In this section
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Step 1: Is it normal? Walnuts (right) typically break bud late in western Oregon while other plants such as cherry (left) have been growing for several weeks.
Step 2a: Look for patterns in the community. All the strawberries do not look the same in this picture. The circular areas have both Verticillium wilt and nematode problems.
Different plants in this community have the same problem along the edges of this nursery bed. Roots froze during a winter cold period.
Step 2b: Look for patterns on individual plants. This Christmas tree has lost many lower needles due to Lophodermium needle cast.
Step 2c: Look for patterns on plant parts. Ringspots and line patterns on these Kalmia leaves indicate necrotic ringspot virus infection.
Dr. Jay W. Pscheidt, Oregon State University
Dr. Cynthia M. Ocamb, Oregon State University
In this section
Surface water sources such as rivers, ponds, and reservoirs for storing runoff water are almost always contaminated and should be disinfested before use in irrigation.
Filtration systems: Top Left - Slow Sand tank. Top Right - Fine sand filter. Bottom Left - Rolling paper filter. Bottom Right - Vibrating screen filter.
Chlorine gas is bubbled through the water, where it combines with the water to form hypochlorous acid (HOCl) and hydrochloric acid (HCl).
Oxidizing agents include bromine, chlorine gas, sodium hypochlorite, calcium hypochlorite, chlorine dioxide, ozone, and activated peroxygen.