1316 THE FKUIT INDUSTRY JN .\KW YOKK STATE 



diameter, or as black oblong spots on the shoots, on the leaf 

 petioles, or on the tendrils. 



The fungus spreads from these spots by means of spores, which 

 are produced abundantly and which are carried to fruit by spat- 

 tering drops of rain. The fruit is quickly destroyed and only a 

 hard black mummy is left. 



The disease may be controlled by timely and thorough applica- 

 tions of bordeaux mixture. The first application should be made 

 before blossoming and the second shortly after the blossoms fall. 

 A, high pressure should be maintained, and the nozzles should be 

 set in such a way that the foliage will be covered. The nozzles 

 should be fitted with replaceable disks having small holes in order 

 that an exceedingly fine mist may be formed. These two appli- 

 cations are the most important, but in a rainy season at least two 

 more applications should be made one when the berries are the 

 size of a pea and a later one just before the berries are large 

 enough to touch each other. These applications should be made 

 with trailing devices and the spray applied by hand, special 

 effort being made to cover the clusters. 



Bordeaux mixture, 4 50, is the most effective material known 

 for this disease. It acts as a preventive, and, to secure best re- 

 sults, should be applied as indicated above whether the disease 

 has appeared or not. The quantity of material applied per acre 

 is not so important as is the evenness of distribution and fineness 

 of the spray. 



DOWNY MILDEW 



This disease also is common in the Central Lakes region and in 

 the Hudson River district. It can be found in the Chautauqua 

 belt in such varieties as the Delaware, the \ 7 ergennes and the vari- 

 ous Rogers hybrids. It has never been seen on Concord, the chief 

 variety of the belt. As distinguished from black rot, the downy 

 mildew is chiefly a foliage trouble and is in general less destruc- 

 tive than black rot. The disease is caused by a fungous parasite, 

 Plasmopara viticola. This fungus passes the winter in fallen 

 diseased leaves. Under moist conditions it passes, by means of 

 spores, from the fallen 'leaves to all green parts. Brown spots a 

 half-inch to an inch in diameter appear on the leaves, the tip of 

 the shoot may be affected and increase in diameter, and the berries 

 may be affected and develop a gray or brown rot. The chief 



