Color abnormalities
leaflets and leaves

Many diseases affecting tomatoes alter the a coloring of leaflets and leaves . Various qualifiers are used to translate these disturbances in colorings of the limbus (figure 1) that we have, for simplicity, divided into 3 general categories of symptoms and exemplified by a few figures:

- Leaflets, mosaic leaves (figure 2);
- Leaflets, leaves partially or totally yellow (figure 3);
- Leaflets, leaves showing other colorings (figure 4).

Figure 1	Figure 2
Figure 3	Figure 4

In the presence of such symptoms, various causes are possible:

• either parasitic

- phytoplasmas of stolbur;

- divers virus responsables de mosaïques et de symptômes assimilés : Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV), Eggplant mottled dwarf virus (EMDV), Pepino mosaic virus (PepMV), Potato virus Y (PVY), Tobacco mosaic virus (TMV), Tomato mosaic virus (ToMV), Tomato spotted wilt virus (TSWV), Pepino mosaic virus (PepMV), Tobacco mosaic virus (TMV), Tomato chlorosis virus (ToCV), Eggplant mottled dwarf virus (EMDV), Tomato yellow leaf curl virus (TYLCV) ;
- some viroids .

• either non-parasitic

- various genetic abnormalities ;
- silvering;
- nutritional disorders;
- an excess of salt;
- various phytotoxicities ;
- temperatures that are too low ;
- mites;
- Aculops lycopersici (acariose bronzée) ;
- des thrips

Other causes, less frequent or absent in France, can be incriminated. For more information, we advise you to consult the work "Les maladies de la tomate" by D. Blancard, published by the Quae editions in 2009.

The most frequently observed anomalies on the leaves are mosaics or related symptoms, but above all more or less marked yellowing of the leaf blade. These color anomalies can take on very distinct aspects depending on the disease, but sometimes be quite similar for very different conditions. This situation makes it very difficult to identify the diseases responsible for such symptoms. We therefore suggest that you carefully consult all the illustrations in this subchapter, which is particularly well illustrated, and take the time to consider the different diagnostic hypotheses formulated in the additional diagnostic arguments.
As the risks of diagnostic confusion between viruses are high on tomatoes, we advise you, in case of doubt, to have a serological or molecular test carried out by a specialized laboratory in order to identify with certainty the virus or viruses responsible.

Note that these conditions also and at the same time cause changes in the shape of the leaves. It is therefore in your interest to refer to the chapter dealing with Leaf shape abnormalities in order to complete your diagnosis.