A number of other biotic as well as abiotic factors can cause brown lesions and root emission appearing on the surface of tomato stems.
 

Thus, several viruses are likely to cause, in addition to the symptoms widely described in the chapter Mosaic leaves , longitudinal brown and necrotic lesions on the stem ( streak ). These extend over a length of a few centimeters to several decimeters (Figure 1). They can be located at the apex of plants, on the stem and petioles. In early infections, whole plants die off and dry out. Among the most often associated with this type of virus symptoms, note as examples, in France, ' Alfalfa mosaic virus (AMV), the Cucumber mosaic virus (CMV).
 

It should be remembered that spots, more or less extensive brown areas   sometimes occur following the use of certain herbicides, when the latter are absorbed by the roots and lead to phytotoxicity . Certain herbicides are also likely to induce the formation of yellowish patches on the stems, accompanied by the local emission of adventitious roots (figure 2) when they are absorbed under the same conditions. Aerial treatments can also cause superficial burns of the tigers resulting in a multitude of beigeish lesions of varying extent.
 

More complete information and photos showing this type of disease can be found in the chapters Growth and anomalies coloring anomalies Leaf .
 

Finally, the various organs of the tomato colonized by the mite Aculops lycopersici tend to take a rather characteristic bronze tint, in particular the stem, the peduncles and the petioles (figure 3) . Leaflets and fruits are also affected; We advise you to consult the chapter Leaf coloring anomalies in order to have more details on this pest.