Crops
Alterations, external anomalies
or internal of the stem
There are many diseases that cause external or internal alterations and abnormalities of the stem . Also, various qualifiers are used to translate these disturbances that we have, for simplicity, divided into 3 general categories of symptoms exemplified below:
- Alterations, cankers on stems;
- Other alterations and anomalies on the stem;
- Alterations of the vessels and / or the marrow.
In the presence of such symptoms, various causes are possible:
either parasitic
- Alternaria tomatophila
- Botrytis cinerea
- Botryosporium sp.
- Didymella lycopersici
- Fusarium oxysporum f. sp. lycopersici
- Fusarium oxysporum f. sp. root-lycopersici
- Phytophthora infestans
- Sclerotinia sclerotiorum
- Thanatephorus cucumeris
- Verticillium dahliae
- Clavibacter michiganensis subsp. michiganensis
- Pectobacterium carotovorum subsp. carotovorum
- Pseudomonas corrugata
- Pseudomonas mediterranea
- Ralstonia solanacearum
- Virus divers
- Aculops lycopersici
- Botrytis cinerea
- Botryosporium sp.
- Didymella lycopersici
- Fusarium oxysporum f. sp. lycopersici
- Fusarium oxysporum f. sp. root-lycopersici
- Phytophthora infestans
- Sclerotinia sclerotiorum
- Thanatephorus cucumeris
- Verticillium dahliae
- Clavibacter michiganensis subsp. michiganensis
- Pectobacterium carotovorum subsp. carotovorum
- Pseudomonas corrugata
- Pseudomonas mediterranea
- Ralstonia solanacearum
- Virus divers
- Aculops lycopersici
- either non-parasitic
- Lightning
- Hail
- Physiological emission of aerial adventitious roots
- Various phytotoxicities
In such a symptomatic context, the diagnosis is sometimes very delicate. Indeed, several parasitic and non-parasitic diseases are capable of causing various symptoms on and in the stems of the tomato. Thus, all parts of the stem are susceptible to damage: bark, endoderm (i.e. cortical tissues), vessels and marrow (figures 1 and 2, see also examples in figures 3 to 6 ). Note that several parasitic diseases do not affect the vessels initially, but later in their development. The transport of the sap ends up being more or less disturbed, which causes wilting, yellowing and more or less complete drying out of leaflets, leaves and plants.
It should be noted that the search for a possible alteration on a rod (sometimes several meters long) must be carried out with great care, and over its entire length. In addition, in order to check the condition of its vessels and marrow, you will have to section it longitudinally and transversely at different levels: near the neck, near the apex, and at several intermediate levels. It should be noted that the so-called "vascular" diseases, affecting more particularly the vessels of the tomato, are at the origin of symptoms in the stem which are quite comparable and are confusing.
Finally, let us add that many aerial diseases of tomatoes can cause symptoms on the stem. Generally, these are accompanied by other manifestations on the other organs of this nightshade which are often more characteristic. Also, we advise you to consult the chapters devoted to these organs, this chapter only concerns the diseases specifically affecting the stem.
- Hail
- Physiological emission of aerial adventitious roots
- Various phytotoxicities
Other causes, less frequent or not encountered in France, are possible:
- des agents pathogènes ; Alternaria alternate f. sp. lycopersici , PHOMA destructive Sclerotinia minor, Verticillium white-black d'autres Pectobacterium ( grams carotovora subsp. atrosepticum , P. chrysanthemi ), d'autres Pseudomonas ( grams Cichorii , P. fluorescens biotype 1, P viridiflava )
- another cause abiotic ; branching of the stem.
Additional information can be found in the work "Les maladies de la tomate" by D. Blancard, published by Éditions Quae. - des agents pathogènes ; Alternaria alternate f. sp. lycopersici , PHOMA destructive Sclerotinia minor, Verticillium white-black d'autres Pectobacterium ( grams carotovora subsp. atrosepticum , P. chrysanthemi ), d'autres Pseudomonas ( grams Cichorii , P. fluorescens biotype 1, P viridiflava )
- another cause abiotic ; branching of the stem.
In such a symptomatic context, the diagnosis is sometimes very delicate. Indeed, several parasitic and non-parasitic diseases are capable of causing various symptoms on and in the stems of the tomato. Thus, all parts of the stem are susceptible to damage: bark, endoderm (i.e. cortical tissues), vessels and marrow (figures 1 and 2, see also examples in figures 3 to 6 ). Note that several parasitic diseases do not affect the vessels initially, but later in their development. The transport of the sap ends up being more or less disturbed, which causes wilting, yellowing and more or less complete drying out of leaflets, leaves and plants.
It should be noted that the search for a possible alteration on a rod (sometimes several meters long) must be carried out with great care, and over its entire length. In addition, in order to check the condition of its vessels and marrow, you will have to section it longitudinally and transversely at different levels: near the neck, near the apex, and at several intermediate levels. It should be noted that the so-called "vascular" diseases, affecting more particularly the vessels of the tomato, are at the origin of symptoms in the stem which are quite comparable and are confusing.
Finally, let us add that many aerial diseases of tomatoes can cause symptoms on the stem. Generally, these are accompanied by other manifestations on the other organs of this nightshade which are often more characteristic. Also, we advise you to consult the chapters devoted to these organs, this chapter only concerns the diseases specifically affecting the stem.