Symptoms
- Leaf deformations
- slow development of the youngest leaves, which can go as far as a total stop of growth; the plants eventually show a stunted appearance (Figure 1), especially if phytotoxicity has occurred prematurely;
- partially or totally deformed leaves, at the periphery more or less serrated (figure 2) or more irregularly cut (figure 3), marbled, blistered and more or less rolled up;
- the more or less marked distortion and / or winding of the leaves, which may be shorter, threadlike (figure 4) and have strongly thickened tissues;
- the corkscrew appearance, crumpled with all the leaves ...
- Leaf discolorations
- yellowing in spots, in more or less well defined areas, sometimes evolving towards tissue necrosis;
- yellowing of the veins and contiguous tissues (figure 5);
- yellowing of young leaves at the apex;
- diffuse yellowing of the leaf blade between the veins (figure 6);
- yellowing of the periphery of the limbus (figure 7);
- diffuse yellowing of the entire blade;
- more or less homogeneous inter-vein yellowing of the limbus, sometimes progressing to tissue bleaching (figure 8);
- bleaching of the leaf blade ...
Other color anomalies may appear: greenish to livid tint of the leaves, dull and / or tan appearance of the blade .
- Leaf lesions and spots
- Lesions, more or less extensive chlorotic spots, quickly becoming necrotic ...
Note that in certain circumstances, pesticides. Such damage can be observed in the presence of herbicide spray carried on the plants by the wind; following treatment with an anti-powdery mildew fungicide, or with a mixture of pesticides (fungicide, insecticide, etc.) and a foliar fertilizer; when adding fertilizer on the fly in the crop ...
Often, only leaves that are well exposed (for example near openings in cultivation under cover) or located on one side of the plants are affected. On these, the symptoms are particularly marked in places where there may have been a greater retention of the suspension of the product (s).
- Wilting, necrotic lesions, leaf dryness (Figures 7 and 9)