Small Fruits 



tissue, though the leaves sometimes turn 

 yellow, and many of them are reduced in 

 size. After the vine dies the leaves still re- 

 main attached to the canes. The best treat- 

 ment is to remove and burn the affected 

 stock, thoroughly stir, air, and dry the adja- 

 cent soil. For further discussion of root-rot, 

 see p. 370. 



Several diseases, the causes of which are 

 not known, do serious injury to the grape. 

 They may be briefly described as follows: 

 California vine-disease.^^'' Since 1884 

 many vineyards in California have been 

 destroyed by this disease. In the first sea- 

 son small, yellow spots appear between the 

 veins. These enlarge and unite to form 

 stripes, leaving only a narrow band of green 

 tissue along the veins. Leaves fall prema- 

 turely and the canes turn black and die. 

 The following season there is reduced growth 

 of canes. By the third or fourth season the 

 vines usually die. Cuttings should not be 

 made from diseased vines. An unnamed 

 disease of somewhat similar character has 

 been described in New York.^"*^ Brunissure. 

 Irregular brown spots appear on the upper 

 surfaces of the leaves and the epidermis 

 falls away, exposing the underlying tissue. 

 Later the browning extends through to the 

 lower leaf surface. Black zones often ap- 

 pear in the wood. Shelling consists in the 

 grapes falling from their stems Ijefore ma- 

 turity. Diseased berries are matted, thick- 

 skinned, and show a brown zone l)eneath 

 the skin. Though the cause of shelling is 

 unknown, it is more common on weak 

 vines. Good cultural conditions lessen it. 



Fig. 68. — Grape 

 necrosis as it 

 appears on the 

 canes. After 

 Reddick. 



