The University of Missouri SCN Diagnostic Clinic works with farmers to identify nematodes that feed on plants. Nematodes are small, microscopic roundworms, and many of these tiny worms live in the soil and attack plant roots. The root knot nematode is one example that can become a problem in tomato production. The root knot nematode enters the root, and as the population increases, smaller adventitious roots are destroyed. Large galls form on the roots and can be easily seen when plants are dug up (Figure 1). Above ground symptoms include plants that are stunted, grow slowly, and wilt easily. They may appear yellow or pale green. Root knot nematodes do not move far in the soil without human interference. Therefore, injured plants may be observed in only a small area of the field.

Figure 1 Galls on these tomato roots are due to root knot nematode infection. Photo courtesy of Walber Gavassoni

The SCN Diagnostic Clinic can confirm the presence of root knot nematode or other nematodes that may infect a crop and are referred to as plant-parasitic nematodes. To submit samples to SCN Diagnostics, collect a sample of at least 1 pint of soil from the problematic area. The clinic will isolate nematodes from the soil and identify the problematic nematodes at $50 per sample. Infected plant tissue is welcome as well. The clinic is on the University of Missouri Campus at 1054 East Campus Loop, Columbia, MO 65211. Samples can be hand delivered or shipped if necessary. In the latter case, please include a note about the problem and contact information. Contact your local MU Extension Field Agronomy or Horticulture Specialist for more information.