Which method is used to test for nematode infestations in plants?

The method involving soil sampling and analysis is the most reliable way to test for nematode infestations in plants. Nematodes, which are microscopic roundworms, primarily inhabit the soil and can be difficult to detect through visual inspection of the above-ground parts of the plant. While some symptoms like stunted growth or yellowing leaves could suggest nematode issues, these symptoms can also be caused by various other plant stresses, making visual inspection an inadequate diagnostic tool.

Soil sampling allows for a more precise detection of nematodes by collecting samples from the root zone where nematodes are most likely to be present. The collected samples can be analyzed in a laboratory setting to identify the types and populations of nematodes present. This scientific approach provides concrete data that can be used to make informed decisions about pest management strategies.

Other methods such as pest traps or watering with nematicidal solutions do not provide a direct assessment of nematode infestation levels and may not reveal the presence or type of nematodes effectively.