Plant viruses cause severe constraints on the growth and productivity of a wide range of economically important crops. Many viral diseases are responsible for the low production of blackgram. In Tamil Nadu Agricultural University (TNAU) at Coimbatore, a TSV causing stem necrosis was noticed to an extent of 5–20 per cent (Oct-Dec 2001). The infected plants exhibit brown and necrotic spots on the young leaves and brown streaks on the petiole and stem. As the disease progresses, the tip of the stem becomes necrotised which leads to death of the plant. It was observed to cause complete yield loss (100%) when it attacked at the early stage of the crop. To minimize the virus incidence, several antiviral proteins (AVPs) were tested. Among the six AVPs tested,
