Nematodes are microscopic creatures which are worm like living in the soil and feed primarily on the roots of plants. They almost there in every soil and if the soil is coarser means more Nematodes.
Rotational crops are one method to control them. Alternating between susceptible to non-susceptible crops is an ideal method to control. But this not possible practically and the common alternative to crop rotation is chemical treatments. Since there are many varieties of Nematodes most chemicals are very specific for certain crops. The other way is to plant specific nematode resistant varieties. This method has its limitations and cannot be relied upon as a solution.
TNTH suggests a nematode assay which will help in healthier plants and thus higher yields. The Nematode population is high when the crops are growing. However the thresh holds used in making recommendations are based on seasons. Avoid sampling when the soil is extremely dry.
The soil samples should be taken till the depth ploughing is done. The samples taken per sampled area can be between 8 to 12 cores. The samples should be placed in a bucket and mixed. A composite sample should be taken from the mix and placed in a plastic bag so it retains the moisture and ensures the nematodes are alive. This composite should be sent quickly to our labs and ensure it is cool else it the Nematodes will be killed. Normally within three days it will be tested and the reports will be ready.