Crops
Late blight symptoms on potatoes
- Organs attacked :
| Leaves | flowers |
| tubers | stems |
- Symptoms :
- Pale green to brownish green spots on the leaflets at first wet. These spots are frequently surrounded by a livid, ill-defined tissue margin (Figures 1 and 2).
- Large sectors of the leaf blade browning and becoming necrotic (figures 3 and 4)
- Browning of the apices (figure 5) and brown cankered lesions on stems and petioles, more or less extensive, and with an irregular outline (figure 6).
- Diseased plants are distributed in clusters in the plots; When the conditions are favourable, the progression of the symptoms on the plants and in the culture is dazzling: leaves, twigs, even plants end up necrosing and drying out completely.
- Signs : presence of a discreet and fleeting white down on the underside of the leaf blade (figure 7); this is made up of the sporocystophores and sporocysts of P. infestans.
- Production areas affected :
| Reunion | New Caledonia |
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7