Spread of the Grape Disease in the Adige Valley

Daily Report.

Bozen, 27 June. The joyful hopes for an abundant and excellent wine harvest, justified this year by the thriving and luxuriant state of the vines, have unfortunately been clouded by the observation that the grape disease, which already appeared last year, has shown itself anew and to an alarming degree. In view of the weighty and adverse consequences threatening our primary agricultural product, we consider it not without merit to communicate here the manifestations of the disease, so far as they have become known to us. In doing so, we cherish the hope that discerning agriculturalists and natural scientists may be stimulated to investigate the deeper cause of the phenomenon and make closer observations, which alone can make possible the discovery of remedies against the affliction and its eradication.

While last year the disease did not appear until late summer, when the grapes were already beginning to ripen, this year it appeared as early as the final days of May, when isolated traces of it showed here and there. Since then, it has spread at a more or less rapid pace almost throughout the entire Adige Valley. Around Bozen, notably in the area of Gries, on the slopes of Rentsch and St. Justina it is frequently encountered; the plateau of Eppan and Kaltern is no less acquainted with the affliction, nor has the valley up towards Meran and the area of Gratsch and Tirol been spared. The spread occurs sporadically and in varied fashion. At times, entire Bergeln are infected by the disease in a single night; at others, it clings for weeks to a single vine without further progress. In some vineyards, the number of infected vines is considerable; in others, only isolated cases are noticeable. Particularly exposed this year are the slopes and sunny locations, whereas these were spared last year; with greater heat, the susceptibility to infection also appears to increase.

The symptoms of the disease begin on the foliage; pale yellow spots appear on the leaf, followed by blisters and wrinkles. As the affliction takes hold, the leaf contracts, and there appears that mold-like coating which, according to microscopic observations made last year, consists of a species of fungus and transfers to the grapes. The color of this coating is ash-gray, but viewed through the microscope it is black; to the touch it feels greasy, dirty, and moist, can be wiped off, whereupon black dots appear on the infected berries. On the vine, the disease initially manifests itself through black spots that later spread over the entire vine; the outermost tip shrivels and atrophies, and growth ceases.

As there was opportunity to observe last year, the consumption of infected foliage is harmful to pigs; in cattle, however, no adverse effects were noticed. The berries themselves acquired a repulsive, bitter taste. They split open, and although the fissure crusted over and healed, the wine produced from them was spoiled and undrinkable. - If, as one is forced to assume, the consequences should be the same this year and the affliction should expand further, a significant loss in this year's wine harvest would be inevitable. How detrimental such an outcome and how threatening the return of the affliction must be to the agricultural producers of the Adige Valley is obvious. Obvious, too, is the necessity of turning serious attention to this condition, in order, if possible, to investigate and bring about a cure for the affliction or avert the grave damages.