Net necrosis causes unacceptable discoloration in processed potato products and is not easily or quickly removed during trimming in processing plants. Consequently, it is difficult to use potatoes containing net necrosis for either processing or fresh packing.
Symptoms are more subtle in plants with current-season infections.
Late season infection of leaf roll virus may show little or no foliage symptoms, although the virus can still move down into the tubers. Tuber symptoms are caused by the selective death and damage to cells in the vascular tissues of the tuber. Symptoms first appear as light to dark brown strands of discoloration in the flesh at the stem end of the tuber. Plants produced from infected seed are not only stunted but also have reduced yield both in tuber numbers and in tuber size. Often the tubers produced by such plants have no net necrosis symptoms.