August is a good time to diagnose those problem areas in your field. Nematode numbers are at a peak, so it is a good time to take a nematode and soil sample to determine if the problem is related to nematodes or soil fertility. A soil sample can be taken six-to-eight inches deep in the root zone and divided into a nematode and soil sample for analysis.
Nematode samples need to be taken when there is good soil moisture and handled properly to prevent the soil from drying out. Improper handling of soil samples can lead to a poor estimation of nematode populations.
The nematode samples need to be placed in a plastic bag and kept out of direct sunlight. They should be placed in an insulated cooler during transit to avoid getting too hot or dry. Excessive heat or drying can kill the nematodes in the sample which result in them not being able to be detected.
Forms and more detailed directions for taking and sending nematode samples to Alabama Extension Plant Diagnostic Lab can be found here.