Final diagnosis


Verticilliosis, Verticillium wilt (Verticillium dahliae )

One or more of the lower leaves partly wilt, turn yellow and dry up. <i><b>Verticillium dahliae</b></i> (Verticillium wilt).
Several leaves of this tobacco plant have turned yellow, wilted and become necrotic. <i><b>Verticillium dahliae</b></i>
Unilateral yellowing of a lower leaf of a Virginia type tobacco. Vascular disease caused by <i><b>Verticillium dahliae </b></i>(Verticillium wilt)
Wilting affects one side of the lamina which will soon turn bright yellow to orange and become necrotic. <i><b>Verticillium dahliae </b></i>(Verticillium wilt).
The condition of the vascular system can also be checked at the midrib of a leaf which demonstrates a unilateral discoloration. <i><b>Verticillium dahliae</b></i>
This leaf has turned yellow, wilted and dried up on one side of the lamina; a so-called unilateral distribution of symptoms. <i>Verticillium dahliae<i>
A longitudinal cut of the petioles of an infected leaf shows the browning of vessels. <i><b>Verticillium dahliae</b></i>1
On this leaf browning of vessels and occasionally of the pith can be observed. <i><b>Verticillium dahliae</b></i>
This Virginia tobacco leaf affected by <i><b>Verticillium dahliae</b></i> shows a damaged lamina zone.
This leaf shows a unilateral browning of lamina which can be compared to that of wilting caused by vascular diseases. <i><b>Verticillium dahliae </b></i>(verticillium wilt)
Several vessel portions show a discreet browning.<b><i>Verticillium dahliae</i></b>
Browning of the vascular system is sometimes rather discrete. Vascular disease
To confirm the presence of this vascular fungus one should check the vessels of the stem. In this case the vessels are of light brown in some stem parts when the stem is split longitudinally. <i><b>Verticillium dalhiae</b></i>
A cross section in the stem shows a marked yellowing of the vascular system. <i><b>Verticillium dahliae</b></i>
Conidiophores of <i><b>Verticillium dahliae </b></i>(Verticillium wilt) are verticillate (branched); they produce unicellular, ovoid-shaped hyaline conidia.