This virus can compromise around 20% of the total grape production.
This disease is visible on all organs of the plant. It reduce the growing rate on the affected plants and it also stops the development of the root system. It also affects the plant’s grafting capacity.
The sprouts coming from the trunk are poorly developed, have differently sized internodes, placed in zig-zag. Sometimes the nodes are very close. The secondary sprouts are more abundant, giving the grapevines a shrub like aspect. The leaves are close and the cordons have double nodes. The length of the cordons belonging to affected trunks is reduced.
Rings or oily stains appear on the leaves of the infected trunks and the leaves end up having a mosaic aspect. The leaves belonging to the affected trunks are also smaller in size, with deformed limbs, are asymmetrical and fan shaped. The leaves have abnormal veins, with irregular edges (sharp and long).
Other symptoms that are characteristic to this disease are represented by the poorly blossomed trunks, the flowers not being able to bear fruit and a decrease in the number of grapes from the vine.
The grapevine fanleaf virus is spread by grafting the grapevine, by selling the infected vegetal material and by nematodes.
Prevention and control
We recommend planting the grapevine on a parcel where grapevine haven’t been grown for more than 3-5 years. It is also recommended to plant on a parcel which has been previously treated against spreading nematodes and to use a healthy planting material when sowing. The grafts used need to be disinfected using thermotherapy, try using grafts that have been obtained from meristematic crops.