96 



THE RAISIN INDUSTRY. 



the foliage with it, or dilute it further with say five hundred gallons of 

 water and spray the vine leaves on both the upper and lower sides. 

 According to Dr. Harkness the efficiency of this spray cannot always 

 be relied on. So far no other fungi have appeared in the raisin districts 

 of this State, nor have we reason to fear that any will attack the vines. 



Downy Mildew f/fcromw^wxj, Greatly Magnified, a. The Fungus Growing out of a Stoma 



of the Vine Leaf. c. Transversal Section of Vine Leaf, showing Fungi 



and its Tuberous Mycelium. 



THE VINE PLAGUE. 



Characteristics. The first, or at least the most characteristic signs 

 of this disease appear especially after a summer rain, or after the first 

 fall rain. The leaves then become spotted with yellow. The fol- 

 lowing season these yellow spots appear as if fused together, and 

 many leaves become entirely yellow, except the veins, which stand out 

 bright green. Some leaves are invaded by the yellow from the edges, 

 while the veins as before remain green. These yellow spots soon turn 

 brown, the leaves dry up and curl slightly backwards and finally fall 

 off, leaving the canes bare. During the very first appearance of the 

 vine plague, many leaves turn b'rown and dry up in certain spots in the 

 vineyard without the previous appearance of any yellow spots. The 

 drying of the leaves proceeds either from the center of the spots, or 

 from the margin of the leaves, destroying both the leaves and their 

 veins. Later on in the fall a new crop of leaves appear, but these 

 leaves are small or very small, bright green and sickly, and do not 

 continue to develop after they have reached a certain size, different in 

 different vines. In red varieties of grapes, the yellow spots in the 

 leaves gradually turn red or claret colored, often resembling the most 

 beautiful autumn leaves. In districts where the disease is common, 

 these leaves are generally known as calico leaves on account of their 

 peculiar markings. 



The canes do not attain their regular growth, and fail to mature in 

 the fall, or mature only in spots, the balance of the wood remaining 

 dull green. The inner parts of the canes are, as a rule, more mature 

 than the tips. Very often only one or two joints nearest the stem 



