Visible symptoms of plant damage often are not seen, particularly in high-yield environments.
Some symptoms do suggest infestation.
Heavily infected plants may appear stunted and may be yellow and chlorotic. Severely infested portions of a field may be oval or rectangular in outline. These areas may have a general yellowish cast and show the most severe damage in the center. SCN can cause yield reduction of 15 to 30 percent on susceptible varieties that show no visible symptoms of nematode damage. In a low-potassium field, SCN infection intensifies the potassium deficiency syndrome.