Fungus Diseases of Plants 151 



disease. The agricultural experiment station bulletins- 

 and special books on spraying will supply full informa- 

 tion. 



221. Diseases of Orchard Fruits, such as brown rot of 

 peaches and plums (Fig. 91); mildew and black-rot (Fig. 

 92) of grapes and other common diseases are controlled 

 by spraying with Bordeaux mixture. The first spraying 



Fig. 93. The apple scab may be prevented by spraying. 

 From Cornell University Junior Naturalist. 



should be before the buds swell, and repeated every few 

 weeks thereafter until the crop is safe. 



222. Grain Smuts. The smuts of oats and wheat 

 (Fig. 87) may be prevented by treating the seed before 

 planting. The spores become lodged on the grain on the 

 hull or fine hairs. When the seeds are planted, the spores 

 germinate with the seed. It is peculiar, but true, that 

 this fungus can infect the plant only in the seedling 

 stage. Therefore, it is plain, that to prevent the blasting 

 of the oats by smut, we must destroy the smut spores 

 on the seed before planting. This may be done without 

 injury to the grain by treating the seeds with dilute 



