112 INTERNATIONAL CONGRESS OF VITICULTURE 



distorted, curled and spotted, with small, dead areas which soon drop out, 

 leaving irregular holes, as shown in Figs. 1 and 2. On the shoots small, 

 dark spots at first appear which enlarge rather rapidly, causing sunken 

 cankers with a more or less reddened margin (see Fig. 2). As the fungus 

 develops and produces its spores on the surface of the cankers the sunken 

 portion becomes ashy gray in color. Under favorable weather conditions 

 the cankers multiply rapidly, and finally destroy the whole shoot. In case 

 of American varieties the young foliage is not so seriously affected and the 

 disease is restricted almost entirely to the under side of the ribs of the leaf. 

 The fungus also attacks the berries during all stages of their development. 

 The most striking and characteristic appearance of the fungus occurs in the 

 lesions produced upon the berries, especially the varieties having light 

 colored fruit. A light brown spot first appears; this increases in diameter 

 and soon becomes surrounded by a bright red zone, while the central portion 

 of the spot becomes ashy gray as the spores of the fungus are developed. 

 These bright colored spots on the fruit have given rise to the common name, 

 "bird's eye" rot, in some sections, owing to their fancied resemblance to the 

 eye of a bird. Fruit affected by this fungus soon dries up and is worthless. 



Three kinds of anthracnose of the vine have been described by French 

 writers, Anthracnose maculee, spotted anthracnose; Anthracnose ponctuee, 

 punctate anthracnose, and Anthracnose deformante, causing malformed 

 leaves and shoots. The spotted anthracnose is the only form known to be 

 caused by Sphaceloma. The punctate anthracnose has recently been investi- 

 gated by Schellenbergs who states that he produced the characteristic effects 

 of the disease by inoculation with Valsa Vitis (Schw.). The cause of 

 Anthracnose deformante is unknown. 



The spotted or true anthracnose is widely distributed in America east 

 of the Rocky Mountains but seems to be rather erratic in its appearance and 

 behavior. A serious outbreak will occasionally occur in a certain locality or 

 in a certain vineyard and become very destructive for a few years and then 

 apparently disappear more or less completely for a period. Its development 

 and spread apparently depend upon particularly favorable combinations of 

 weather conditions. Hot, wet weather during the early part of the season 

 seems to be most favorable for it. Several very serious outbreaks have 

 occured the present season in Southern Texas upon vinifera grapes and also 

 on varieties derived from Vitis borquiniana, such as Black Spanish (Lenoir). 

 The accompanying reproduction of photographs shows the effect of this dis- 

 ease on leaves and shoots of vinifera grapes (Tokay) from Texas. As this is 

 in a semi-arid region little trouble from this disease would ordinarily be antic- 

 ipated, but the past season has been unusually wet and this is probably the 

 primary factor in accounting for the unusual development of this disease in 

 that region. While some of the vinifera varieties very widely grown in 

 California are subject to this disease in humid regions no cases have yet 

 been reported so far as we know from the irrigated regions of California. 



Certain American varieties appear to be generally more susceptible than 

 others. Champion, Diogenes, Moore's Diamond, Missouri Riesling, Norton, 

 Salem, and Vergennes, are particularly liable to attacks of this disease, while 

 the Concord is rarely affected by it. Of the vinifera grapes, Thompson's 



8 Schellenberg, H. C. Tiber die Schadigung der Weinrebe durch Valsa 

 Vitis (Schw.) Fckl. Ber. d. Deutsch. Bot. Gesellsch. 30.586:593. 1912. 



