How important is crop health management for minimizing soybean cyst nematode damage?
Fig. 17. Yield difference between SCN-susceptible (S) and resistant (R) soybean varieties was not significant in manure-applied soil, but there was a big difference in the soil without a manure application.
It is important to maintain proper soil fertility, provide good drainage, and control other diseases, insects, and weeds. Insurance pesticide applications, however, are not an effective part of SCN management. Appropriate cultural practices such as maintenance of good soil fertility may enhance plant growth, increase tolerance of plants, and minimize yield loss to SCN (Fig. 17).
In Minnesota, no-till or reduced tillage does not reduce or has a limited effect on SCN egg population density. In fact, conventional tillage may improve early season root development, and reduce damage to soybean caused by SCN. These practices, however, do not reduce SCN population density in a field. To limit the growth of SCN populations, they must be integrated in a management program with a rotation of nonhost crops and resistant varieties.
In some fields, SCN management is complicated by the presence of microbial pathogens and nutritional deficiencies. For example, if chlorotic symptoms are observed in a field planted with an SCN-resistant variety, root rot disease and/or nutrient deficiency (such as iron deficiency) may be involved. In this case, action should be taken to identify and manage all of the crop stresses.