No. 17 for more detailed information on field patterns. The clues or symptom patterns that the investigator has to work with often consist of a set of symptoms or signs observable on individual plants. Symptoms and signs can be subdivided into different categories. By categorizing the symptoms and then using a symptomology key, the investigator can quickly eliminate a number of possibilities. The key contains only a partial listing of potential causes of the symptoms described.
Entire plant stripped of leaves or all leaves show penetrating or shredding damage.
Poor soil conditions Whole Plant Stunted or Groups of Plants Stunted. Spray damage Leaves with veins browned. Chemical damage Leaves with interveinal areas browned or off-color. Herbicide damage Alternate qreen and vellow areas. Leaves with holes only.