Final diagnosis


Potato virus Y (PVY)

Spotted interveinal yellowing and early leaf necrosis.  <b> Potato virus Y </b> (<i> Potato virus Y </i>, PVY).  Necrogenic strain.
Diffuse brown necrosis covering all the leaflets, accompanied by yellowing.  <b> Potato virus Y </b> (<i> Potato virus Y </i>, PVY).  Necrogenic strain.
Diffuse brown necrosis covering all the leaflets, accompanied by yellowing.  <b> Potato virus Y </b> (<i> Potato virus Y </i>, PVY).  Necrogenic strain.
Diffuse brown spots, necrosis (beginning of attack).  <b> Potato virus Y </b> (<i> Potato virus Y </i>, PVY).  Necrogenic strain.
These brown and diffuse necrotic lesions frequently have a fairly generalized distribution on the leaves, which differentiates them from those of bacteriosis.  <b> Potato virus Y </b> (<i> Potato virus Y </i>, PVY).  Necrogenic strain.
Necrotic brown interveinal spots on the upper surface of a leaflet.  <b> Potato virus Y </b> (<i> Potato virus Y </i>, PVY).  Necrogenic strain.
Flexuous virions 15 nm in diameter and about 750 nm long (potyvirus type).  <b> Potato virus Y </b> (<i> Potato virus Y </i>, PVY)