Excoriose
Excoriose is caused by the fungus Phomopsis viticola. All grape varieties are susceptible to Excoriose, a disease that manifests itself mainly through the bottom of the grapevine’s branches. The fungus overwinters in the form of pycnidia and mycelium in the buds at the bottom of the stalk. When the first spring shoots appear, the infection caused by the pycnidia spores takes place. The mycelium that hibernated in the buds destroys them before budding.
Stalks:
- necroses in the internodes at the bottom of the stalks - fissures at the bottom of the shoot - dead basal buds - whitish areas with black points (pycnidia) on ligneous stalks
Leaves:
- necrosed points with a yellow halo at the bottom of the blade and ribs - dark spots on the petioles and main ribs - deformed leaf - defoliation at the bottom of the stalks
Bunches: - dark spots on the peduncle and rachis - dry bunches - bunches that become violet blue after veraison
Cultural control:
- Use only material from healthy vines in grafting and reject the buds at the bottom.
Chemical control:
azoxystrobin sulphur folpet fosetyl-aluminium mancozeb metiram propineb
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