THE LEAF BLOTCH DISEASE OF HORSE-CHESTNUT 419 



For treating large plantings of horse-chestnut trees in the nursery, 

 a traction duster such as is illustrated in figures 91 and 92 is desirable. 

 The machine is especially light in weight and runs between the rows, 

 the dust being discharged from the two pipes in the rear. One man and 

 a horse are all that is required to operate this machine. 



Although spraying is effective in controlling leaf blotch, the dust method 

 is preferable, as there is less danger of injuring the foliage by burning; 

 further, the dust mixture can be applied more thoroughly and with greater 

 facility than the spraying solution. The dust mixture is somewhat more 

 expensive than the spraying solution, but ;ts greater cost is offset by 

 the consequent saving in time and labor. 



