Although this disease occurs in Italy, chief damage has been wrought in California. At one time it was the most serious of the several vine diseases in that state. It first appeared there in 1884, as nearly as can be determined, and within two years many vineyards were destroyed in the vicinity of Anaheim, California. The destructiveness of the disease in this locality has given rise to the name Anaheim disease. Up to the year 1895 about 30,000 acres of productive vineyards were killed. The loss has been estimated at not less than $ 20,000,000.

Symptoms

Except for the older pathologists who have known the disease from the first, few are able to recognize with accuracy the California vine disease. When it first appears in a vineyard it shows here and there in a sporadic fashion. But in time it increases; it is cumulative. The leaves, canes and roots are affected. During the first season symptoms of the disease in a vineyard show on the foliage. Small yellow spots appear in the tissue between the veins. These enlarge and unite, forming yellowish stripes which broaden and die at the center. Eventually there is a conspicuous brown stripe of dead tissue bordered by yellow on each side, leaving only a narrow band of green tissue along the veins. Leaves fall prematurely, dropping from the base of the canes first. The immature portions of the canes turn black and die, and the berries become dry and hang to the vine, or rarely fall. The next season there is a reduced growth of the canes. Often the foliage will appear normal in the spring, but it becomes spotted during the summer, followed by a premature defoliation and death of the canes as described for the first season. The third spring the vine may fail to put out new growth, or it may grow until midsummer and then die. In some cases affected vines live for five years. The roots on diseased plants decay first at the tip, then other parts succumb, and finally the whole system is involved.

Cause

The disease is not only destructive but obscure. As yet the cause is not known. It has been concluded by many authorities that it is of non - parasitic origin. They claim that overbearing is not an impossible cause. It is also held that the disease is due to some weakness in the functions of absorption and translocation of water. There is some evidence that the causal factor, whatever its nature, is transmitted by cuttings.

Control

The use of cuttings from healthy vines from a district where the disease does not occur is advised. Healthy cuttings, however, may contract the disease if grown among affected vines.

References

Pierce, N. B. The California vine disease. U. S. Agr. Dept. Veg.

Path. Div. Bul. 2: 1-222. 1892. Pierce, N. B. Grape diseases on the Pacific Coast. California vine disease. U. S. Agr. Dept. Farmers' bul. 30: 7-10. 1895. Butler, O. Observations on the California vine disease. Torrey Bot. Club Mem. 14:111 - 153. 1910.