The Grape. 141 



lodge them. As the insects pass the winter under dead 

 leaves and other rubbish, many may be destroyed by rak- 

 ing these materials from the vineyard late in autumn or 

 early in spring. 



203. The principal fungous diseases attacking the grape 

 are the black rot {La'stadia B'uUccJlil), the downy mildew 

 {Peronospem viticola), the powdery mildew {Undnida spi- 

 ralis) and the anthracnose {Sphaceloma ainpelinum). These 

 all attack both the foliage and the fruit, and are propagated 

 by spores deposited on these parts. They are often very 

 destructive unless prevented by timely treatments. 



204. The black rot is one of the most serious diseases of 

 the grape, especially in the south. Some of the symptoms 

 on the shoots are dark, oval, slightly-sunken areas, of 

 which the centers are thickly studded with very small 

 pimples. The affected parts of the leaves are generally be- 

 tween the veins, have rounded outlines and are of a dark, 

 reddish-brown color. The fruits are commonly attacked 

 when nearly or quite full-grown. The part affected is 

 blackened and characteristic pimples appear; the berry 

 shrivels and becomes strongly ridged and the seeds project 

 prominently under the drawn skin; the entire berry is 

 then black, with minute elevations thickly scattered over 

 it. In warm, moist weather the disease progresses very 

 rapidly, greatly reducing the crop in a few days. Individ- 

 ual berries in the cluster often escape harm. 



Preventive measures. Three thorough sprayings with 

 Bordeaux mixture, the first beginning as soon as the ear- 

 lier leaves are expanded, the second after the vines have 

 blossomed, and the third 2 to 4 weeks later, largely prevent 

 the attack. If the weather is warm and wet, later spray- 

 ings, 10 to 14 days apart, will be necessary. After the ber- 



