COLUMBIA, Mo. – University of Missouri Extension, SCN Diagnostics and Missouri Soybean Merchandising Council are again offering free testing for soybean cyst nematode (SCN), the No. 1 pathogen of soybean in the United States.
Mandy Bish, MU Extension plant pathologist and director of the SCN Diagnostics clinic, says Missouri farmers can submit four soil samples for free SCN egg counts to the clinic in Columbia. Additional tests are available for a nominal fee. Soybean infected with SCN often appear healthy above the ground, making the pathogen difficult to detect, says Bish.
SCN is a microscopic pest that damages soybean roots and reduces the plant’s ability to take up water and nutrients, leading to stunted growth, poor pod development and significant yield loss.
A higher percentage of Missouri soybean fields have detectable levels of SCN compared to a decade ago, and those fields also have higher population densities, according to 2024 research by MU doctoral student and senior research specialist Jeff Barizon, who is currently in the second year of a statewide survey to identify parasitic nematodes in Missouri soybean fields.
Fall, near or shortly after harvest, is the preferred time to test, says Bish.
She recommends sampling of fields that have never been tested or were tested more than five years ago.
Sampling for SCN is a little different than sampling for other purposes, says Bish. Recommended soil cores are 1 inch in diameter by 8 inches deep and taken in a zigzag pattern. Divide fields into sections of 10-20 acres using natural boundaries such as different topographies, areas where sudden death syndrome or SCN symptoms appeared previously and low-yielding areas of the field.
Nematodes to not appear uniformly in fields, so it is important to take samples using recommended methods.
Download the sample submission form and learn more about the sampling and submission process at https://scndiagnostics.com.
Contact the laboratory at 573-884-9118 or [email protected]. You can also contact Bish at [email protected] or 573-882-9878.
SCN Diagnostics is a partnership with the University of Missouri and MU’s College of Agriculture, Food and Natural Resources.
