Source: University of Wisconsin

Recognizing a nematode problem is difficult because above ground symptoms are nondescript; such as thin stands, uneven plant height, and stunted plants. These symptoms can be confused with weather stress, nutrient deficiencies, insect damage, herbicide injury or soil compaction. The only sure way to confirm the presence of nematodes is by soil testing.

Nematodes that feed on corn roots are present in most fields. However, that does not necessarily make them a cause for concern because it's their population density that is important. However, in the case of soybean cyst nematode (SCN), it's simply a yes or no question. If SCN is confirmed by soil tests, resistant soybean varieties should be planted in the future. Unfortunately, nematode resistant corn hybrids are not currently available. So managing nematodes in corn will depend on crop rotation, proper soil fertility and chemical soil or seed treatments. 

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