Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Published on Oct 16, 2013
Soybean Vein Necrosis Virus Soybean growers in the North central region are facing a potential new threat to soybean production due to the detection of a novel soybean viral disease, Soybean Vein Necrosis Virus (SVNV). SVNV is a new Tospovirus that was first discovered in soybean fields in Tennessee in 2008. Currently the disease has been detected in sixteen states in the southern and north-central region including Indiana. The symptoms begin with vein clearing followed by chlorosis or appearance of light-green to yellow blotchy patches near the main vein, followed by necrosis or dying of the leaf tissue at late stage of infection; hence the name Soybean Vein Necrosis Virus (SVNV).
Thrips vector SVNV is transmitted from plant-to-plant by soybean thrips. Adult thrips are tiny insects only 1.5-2 mm (or about 1/16") in length with a yellow body, a dark thorax and two distinct black crossbands on the forewings. Immatures are usually pale yellow to straw-colored. Thrips feed primarily on the underside of leaves, especially along the veins. When flowers are present on soybeans they will often be found inside the flower feeding on pollen. Both immature and adult feeding often causes small yellowish or whitish scars where they penetrate individual leaf cells and suck up the cell contents. This damage is usually insignificant from a pest management perspective and thrips are not considered important pests of soybeans in the Midwest region. However, when thrips populations are high, leaves become crinkled. In rare cases, plants may be killed. Soybean is particularly susceptible to thrips damage early in the growing season from growth stages VE to V6.
Management Options The incidence of SVNV in soybean fields, and the economic impact (if any) on soybean production have not been determined in Indiana. Since disease transmission is facilitated by infestations of the thrips that vector the disease, it is critical to monitor insect vector populations in the region or state in order to try to anticipate future epidemics. Current disease control strategies are based on assumptions from related Tospoviruses and rely on managing the thrips vector using insecticides . Once the importance of this virus to soybean production has been assessed, we will be able to refine these approaches and identify new management strategies if necessary to minimize the potential impact of SVNV in Indiana soybeans.