SoRiE Diseases of Beans. 299 



It is by means of these spores that the disease is spread. The black 

 winter spores (Fig. 115) appear later. They result from the late in- 

 fections by the summer spores. The mycelium never spreads far from the 

 point of infection and, unless these points are numerous, but little damage 

 is done to the leaf. The disease winters in the old leaves. 



Treatment of Rust 



While this disease is not common and is rarely destructive, yet it is 

 desirable that it should not become well established on a farm. Under 

 very favorable conditions it might become sufficiently abundant materially 

 to injure the crop. Therefore, it is well to learn to know it and so be able 

 to stamp it out whenever it appears. Since the disease winters only in the 

 diseased tops, it is readily exterminated by burning all diseased plants after 

 the beans are harvested. When beans are sprayed for anthracnose this 

 disease will also be controlled. 



IV. APPARATUS FOR SPRAYING BEANS 



Any sprayer that will thoroughly cover every part of tJie plant with 

 the Bordeaux mixture may be used. It is not possible to recommend any 

 one machine as the best for spraying beans. The kind of power used is im- 

 material so far as effectiveness is concerned, provided it gives sufficient 

 pressure. The grower must decide for himself what power will be most 

 desirable in his case. The important thing aside from the pressure is the 

 arrangement of nozzles. Fig. 109 shows an arrangement of nozzles which 

 are said to be very satisfactory. Below is given a list of spraying machine 

 manufacturers who furnish with their machines nozzle arrangements for 

 spraying beans (probably others will also furnish them) : 



Niagara Sprayer Company, Middleport, N. Y. Liquified Carbonic 

 Gas. 



The E. C. Brown Company, Rochester, N. Y. Compressed air, com- 

 pressed by power from the axle. 



The Gould's Manufacturing Company, Seneca Falls, N. Y. Hand 

 power or Gasoline engine. 



The Standard Harrow Company, Utica. N. Y. 



Field Force Pump Co., Elmira, N. Y. 



Bateman Manufacturing Co., Grenloch, N. J. 



