Final diagnosis


Black soft rot of stem and leaves, Hollow stalk (Pectobacterium spp.)

A wet and black rot is very characteristic of this pathogen, it is often called "black leg", <i>Pectobacterium</i> sp. (<i>Erwinia </i>sp.)
When the inoculum pressure is high and conditions are particularly favourable, the bacteria cause irregular and limited spots of dark brown to black, surrounded by a yellow halo, <i>Pectobacterium </i>sp. (formerly <i>Erwinia </i>sp., barn rot)
A large, wet, dark brown to black lesion on the leaf. <i><b>Pectobacterium</i> sp.</b> (<i>Erwinia</i> sp., barn rot)
A moist, brown lesion is forming around the leaf veins, the leaf turns yellow and the tissues will quickly collapse. <i><b>Pectobacterium</b></i> sp. (<i>Erwinia</i> sp.)
Colonisation of sepals and peduncles by the bacterium; they turn black. <i><b>Pectobacterium</i> sp.</b> (anc. <i>Erwinia</i> sp.)
<i><b>Pectobacterium</i> sp.</b> (<i>Erwinia</i> sp., black leg, hollow stalk)
The bacterium has taken advantage of stripping wounds to penetrate and colonise the stem. It shows a fairly large black lesion. <i><b>Pectobacterium</b></i> sp. (formerly <i><b>Erwinia</b></i> sp.)
A quickly developing black rot has started from a stripping wound. <b><i>Pectobacterium</i> sp.</b> (anc. <i>Erwinia</i> sp.)
The pith inside the stem is totally brown and glassy. P<i><b>ectobacterium</b></i> sp. (<i>Erwinia</i> sp., <b>black leg</b>, hollow stalk)
The pith is affected, it has completely liquefied and disappeared. <i><b>Pectobacterium </b></i>sp. (<i>Erwinia</i> sp., Hollow stalk)
A wet, brown rot is decaying the cortex at the stem basis of this tobacco plant. <i><b>Pectobacterium</i> sp.</b> (<i>Erwinia</i> sp., hollow stalk)
A bacterium has developed in the veins and surrounding tissues, rotting the tissue. Contaminations may have occurred at topping or during harvest. <i>Pectobacterium</i> sp. (barn rot)