FIRE BLIGHT 279 



the plant tissues, and it is impossible to control the dis- 

 ease by spraying. On account of its prevalence, in cer- 

 tain sections of the country, many of our standard pears 

 cannot be grown. In many of the important pear-grow- 

 ing regions, it annually kills thousands of trees and is prob- 

 ably the most dreaded of all pear diseases. It appears 

 early in the spring at blossoming time and is believed to 

 be carried by bees from tree to tree. The blight attacks 

 the tips of the young growing branches and works its way 

 down to the larger limbs. If not checked, it spreads so 

 rapidly that in a single season, an entire orchard may be 

 ruined by it. It causes the leaves to turn dark brown or 

 black and the infected branches to shrivel and dry. 



Although this disease cannot be cured it can generally 

 be controlled. Certain varieties of fruits are more suscep- 

 tible to fire blight than others. The Russian varieties of 

 apples such as the Wolf River and the Alexander are very 

 susceptible, as well as the Clapp's Favorite and the Bart- 

 lett pears, while the Kieffer pear seems to be especially 

 resistant. Hence the necessity for selecting resistant 

 varieties. As the blight infects most readily the vigorous 

 growing branches, infected orchards should be checked in 

 their growth. The trees should be kept in a strong healthy 

 condition, but they should not be allowed to produce soft, 

 sappy, luxuriant growths. All forms of nitrogenous fer- 

 tilizers should be withheld and if the orchard has been 

 tilled, it should be seeded at once. Care should also be 

 taken not to leave wounded parts of the trunk or branches 

 exposed. 



The trees should be watched for the first signs of the dis- 

 ease upon the tips of the branches, especially during the 

 rapid growth of the spring. Infected branches should be 



