A recent sample received at the University of Illinois Plant Clinic presented confusing symptomology, according to University of Illinois Plant Diagnostic Clinic and Integrated Pest Management coordinator Suzanne Bissonnette.
New leaves were puckered; older leaves were just a bit off color. The sample plant was not stunted, although the client reported that there were stunted plants in that area of the field.
Causes of puckering include herbicide drift or carryover, heat, and leaf hoppers. None of these possibilities seemed to explain the symptoms.
"We had the sample tested for virus infection," Bissonnette explains. The sample was positive for a virus that is rather new to this area, soybean dwarf virus (SbDV).
Soybean dwarf virus has a serious economic impact in Japan. Symptoms are dwarfing and reduced seed set of the soybean plant, which can be severe if the plant is infected in the seedling stage.
"Our sample was not severely dwarfed, unlike other plants in the field, most likely because it was infected later in season," Bissonnette says.