1. Frost: Plants develop a water-soaked appearance as they thaw. Frosted tissues later turn brown and desiccate. Frost injury is erratic and a plant may be killed next to another plant that appears uninjured (Photo 41).
2. Insecticides: Close contact between insecticide and sugarbeet root can blacken or constrict root growth. The injury in Photo 42 was caused by an in-furrow application of chlorpyrifos (Lorsban).
3. Water: Saturated soil can cause sugarbeet to become a bright yellow with leaves that are more erect than normal (Photo 43). Water damage can cause sugarbeet to become more susceptible to postemergence herbicides. In Photo 44, the center two rows were not herbicide treated; the four rows of injured sugarbeet on each side of the center two rows were treated with postemer-gence sugarbeet herbicides. The relatively healthy sugarbeet at the rear of the plots beyond the signs was less water stressed than the area in front of the signs. Water stress plus herbicide caused more sugarbeet injury than water stress alone or herbicides alone.
4. Diseases and Insects: Many diseases and insects affect sugarbeet. The "Compendium of Beet Diseases and Insects" published by the American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121 has an extensive description and pictures of symptoms of diseases and insect damage as well as nutritional disorders, drought, hail, lightning, crusting, salt injury and others.