THE BLACK ROT 



81 



vious year^ and so are supposed to start the disease for 

 the season. Full accounts of the development of these 

 various spores will be found in the articles referred to 

 below, under the head of Literature. 



Treatment. — Spray with the ammoniacal solution 

 of copper carbonate or the Bordeaux mixture five to 

 eight times^ making the first application when the buds 

 begin to swell, early in May in the jSTorthern States, and 

 repeating at intervals of fifteen days. In case Bordeaux 



FIG. 39. OUTFIT FOR SPRAYIXG GRAPES. 



mixture is used, substitute the ammoniacal solution for 

 the last one or two sprayings, to avoid spotting the fruit. 

 The time of the first application will, of course, vary 

 with the latitude, — earlier in the South than at the 

 North. A convenient spraying outfit for vineyard use 

 is illustrated in Fig. 39. It consists of a barrel with 

 pump attached, mounted crosswise in a Avagon. One 

 man drives and pumps', and another sprays the vines 

 behind the wagon. The hose terminates in an S-shaped 

 6 



