Affected crops may show one or more of the following signs of attack: slow/stunted growth, yellowing of the leaves, wilting of the plant despite adequate soil water content, and collapse of individual plants. Severely infected seedlings produce few roots and usually die rapidly. Heavy infection of older plants causes the plants to wilt unexpectedly and die off early. Swellings, or galls, develop on the roots of infected plants, as the result of nematode-induced expansion of root cells. The galls vary in size from slight thickenings to lumps 5 to 10 cm across.