220 THE DISEASES OF FRUITS. 



spraying is in itself injurious and is generally proscribed. 

 Therefore but little remains but to use the knife judiciously. 

 It has been determined that the vigor and growth of the 

 tree have their influence, and any highly nitrogenous manures 

 that stimulate to an undue growth of succulent wood is con- 

 ducive to blight. When it is remembered that the long withy 

 water sprouts are the most certain to blight, it suggests that 

 the feeding and culture should be such as to give a medium 

 growth of strong healthy wood ; in fact, the orchardist should 

 strive for the development that is the most likely to bring the 

 best crop of fruit. 



The Leaf Blight (Entomosportum maculatum Lev.) is one of 

 the most common and destructive of the diseases of the pear. 

 It is recognized by the ashy spots upon the foliage and the 

 premature falling of the leaves. Sometimes whole orchards 

 will become bare of foliage in midsummer, and the half-grown 

 fruit shrivels and becomes worthless. The pears are not ex- 

 empt from the disease, the fungus causing at first blotches 

 that may be purple or brown, followed by a cracking of the 

 fruit and a failure to develop to useful size. The difference 

 between the appearance of the blight upon the foliage and 

 fruit would suggest unlike causes, but under the microscope 

 the fungus is seen to be the same. This is a good illustration 

 of the influence of the infested substance upon the appearance 

 of the fungus, there being a much firmer tissue in the fruit 

 than in the leaf and a consequent cracking of the former while 

 the latter is sooner killed and turns to an ashy gray. 



Remedies. There have been many extended trials of fun- 

 gicides for the Leaf Blight, and they all show that the disease 

 can be controlled. At the Geneva, New York, Experiment 

 Station the results have been favorable with Bordeaux mixt- 

 ure, the formula for which is given under the head of reme- 

 dies for apple scab. (See Fig. 282, where the scab is shown 

 upon the unsprayed fruit and the pears are nearly free when 

 sprayed.) 



The writer has had excellent results with Cupram, made 

 according to the following formula : 



Copper carbonate, 5 ounces 



Strong ammonia, 3 quarts 



Water, 50 gallons 



