Michigan State University (MSU) Extension knows that all vegetable crops, especially carrots, are susceptible to plant-parasitic nematodes, so it offers sampling tips for farmers.
The timing of the sampling is a vital start to the process. Samples must be taken before the ground freezes in the fall or after it thaws in spring. However, the exact time to take the sample depends on the type of nematodes for which the farmer is testing. For example, the northern root knot nematodes need to be tested earlier in the fall or later in the spring in order to detect the eggs.
The second tip is to make sure to have the correct equipment. MSU Diagnostic Services offers a form to submit and suggests gathering the following tools before starting the sampling: a soil probe or shovel, a bucket or large plastic bag, a sealable container for the final samples, and a marker for labeling.
MSU suggests taking separate samples depending on the risk for problems. This way, farmers can target specific areas of their farms to treat instead of treating the entire farm, which may not need the treatment. It is also important to plan a walking path that will give the farmer the best path to take 20-50 samples throughout the farm. After the samples are collected, they need to be stored in a cool place in airtight zip-lock bags. Finally, the form needs to be filled out correctly and mailed with the samples so that they arrive during the week and don’t sit on a hot loading dock all weekend.
MSU Extension has experts the farmer can talk to about specific results to make an informed decision about how to treat the nematodes.