Currently, experiments are being conducted to determine the host range of the virus. This crucial step, while time consuming, is extremely important to combat SVNV because the virus can hide in other plant species (even without showing any symptoms) that will serve as a constant inoculum source, undermining the efforts to eliminate the virus from the system.

Several viruses have been documented to be seed-transmitted in soybean. Even though viruses in the group that contains SVNV are not known to be seed-transmitted, we will be testing SVNV for this property as even that minimal possibility can be important in the overall movement of the virus between different areas.

Viruses can result in yield losses in single-infections, but there is a large amount of data reporting that viruses can affect yield in a major way when two or more accumulate in a plant. Our goal is to evaluate the effect of SVNV on yield when found in plants alone and with other soybean viruses such as soybean mosaic or bean pod mottle.

While we are accumulating data on the virus, we have started testing for resistance in cultivars and advanced selections. Several accessions from the program of Dr. Stella Kantartzi (Southern Illinois University) are being tested and similar work will soon begin in Arkansas in collaboration with Dr. Pengyin Chen.

We are early in our experiments and presently do not know enough about the virus and the disease to make recommendations, but we want growers to be aware of the disease.

As this work moves forward we will determine the yield effect of the virus in single and mixed infections with other viruses and will eventually be able to make recommendations on the necessity of pesticide usage to eliminate the vector(s).

This will be region-dependent, but we have a strong network assembled which includes (in addition to the previously mentioned individuals) Dr. Tom Allen and Dr. Sead Sabanadzovic (Mississippi State University) and Dave Johnson (Missouri Department of Agriculture).

Through this team, information will be disseminated to growers to minimize input and maximize profit. We also expect to find germplasm that shows tolerance or even immunity to the virus that will eventually make its way into commercial cultivars.

e-mail: Yannis Tzanetakis