Search results
Results from the WOW.Com Content Network
Foliar symptoms typically begin appearing in mid-summer as irregular blotches on leaf blades at the base of infected grapevines. Over time, the blotches spread upward from the base to the top of the grapevine canopy. [9] [10] In red grape varieties, the blotches are red; in white grape varieties, the blotches may be pale green to pale yellow. [2]
Because of its effect on grape yield, GFLV is a pathogen of commercial importance. It is transmitted via a nematode vector, Xiphinema index. [3] This nematode acquires the virus through feeding on roots of an infected plant, and passes it on in the same manner. Host and Symptoms: The host for Grapevine fanleaf virus or GFLV is the vitis species.
This is a list of diseases of grapes (Vitis spp.). Bacterial diseases. Glassy-winged sharpshooter, the primary carrier of PD. Bacterial diseases;
The disease cycle begins with the overwintering structures. The grape black rot pathogen overwinters in many parts of the grape vine, especially mummies and lesions, and is able to overwinter on the vineyard floor. [3] In fact, "Viable lesions capable of producing conidia can persist in wood for at least 2 years."
Grapevine fanleaf virus (GFLV), the cause of fanleaf degradation, is the most destructive viral disease of grapes worldwide. Xiphinema index was discovered to be a vector of this disease in the 1950s. It causes yellow mosaic and bands on the leaves, and may result in an 80% reduction in fruit set, causing huge economic losses.
Phomopsis cane and leaf spot is a disease that causes symptoms in the common grapevine species, Vitis vinifera, in many regions of the world. [2] This disease is mainly caused by the fungal pathogen, Phomopsis viticola, and is known to affect many cultivars of table grapes, such as Thompson Seedless, Red Globe, and Flame Seedless. [3]
Those symptoms are related to callose deposition at the sieve plates and subsequent degeneration of the phloem. Although no resistant cultivars of Vitis vinifera or rootstocks are known so far, the various grape varieties differ considerably as far as symptom severity is concerned. Chardonnay and Riesling are among the most vulnerable varieties.
Common symptoms in infected grapevines include stem pitting (when the outer layer of the stems of the grapevine to peel off). Although there is a treatment available to cure infected grapevines, it is not one hundred percent effective, so preventative measures are the best solution to the virus.