Plant Pathology
Factsheet

The soybean cyst nematode causes many millions of dollars worth of damage to Kentucky soybean fields each year. This occurs even though damage is almost totally preventable and control are inexpensive. This situation exists because a large number of soybean producers are unaware that cyst nematode is damaging their crops. In most cases the soybean cyst nematode will cause significant yield reductions without producing any detectable symptoms in soybeans. When symptoms do occur, they are frequently thought to be associated with some other factor, aside from cyst nematode infection. The point is, what you don't see can be hurting you. To make matters worse, many farmers are so used to certain fields producing low to moderate yields, that they never consider the possibility that those fields may be capable of producing much higher yields.

The first step in managing SCN is to find out if the pest is a problem on your farm. The SCN Laboratory at Princeton was established in 1985 to help farmers answer this question. Laboratory-based SCN analyses will tell you whether or not specific fields are infested with SCN, and the severity and possible consequences of the infestation when SCN is detected. The laboratory also provides short and long term management strategies to farmers with problem fields.

Soil samples for SCN analysis can be collected anytime from late September through late March. Nonetheless, fall is generally considered to be the best time to collect samples. There are several reasons for this: 1) SCN populations will be at their peak, 2) soil conditions are more favorable for sampling, and 3) fall sampling allows you more time to make adjustments in your production plan for next spring if SCN problems are detected.

The most common questions received by the SCN Lab are "which fields do I need to sample?" and "how do I collect samples?". In answer to the first question, sample only those fields that are slated for soybean production next spring. This is especially important if you are planning on planting an SCN susceptible variety There is no need to sample fields that will be planted to corn next spring. However, make sure those fields are sampled in subsequent years prior to your planting soybeans. As far as the method of sampling, stop by your county extension office and ask for a copy of the SCN Analysis Form. On the back of that form you will find a detailed, easy to follow description of sampling fields for SCN analysis. The fee for conducting an SCN analysis is $8.50 per sample.