FIRE BLIGHT. 



the pear trees that are planted Hved ten 

 years on account of this destructive agent." 

 E. H. S. Dart stated that the severities of 

 winter were not so much to be dreaded as 

 the ravages of blight. He had, in 1874, one 

 to two thousand trees affected. Dr. P. A. 

 Jewell, in 1876, lost 10,000 Tetofsky apple 

 trees by it. Bailey, of Cornell, declared 

 that fire blight was undoubtedly the most 

 serious disease with which the quince 

 grower has to contend. It was the same 

 disease which was so destructive to pear or- 

 chards in certain years and to certain varie- 

 ties of apples, particularly the crabs. Selby, 

 of Ohio, reported that the disease ranked 

 among the most destructive known to the 

 orchardist in his State. Chester, of Dela- 

 ware, announced that pear blight was of un- 

 usual severity during the season of 1901. 

 and caused much alarm because of its rapid 

 spread through the orchards of the State. 

 In 1895 its ravages were most severe on 

 apple trees in the vicinity of Hamilton and 

 Burlington Bay. J. Craig gathered infor- 

 mation as to the character of injury of the 

 disease from fruit growers throughout this 

 province, and a number of these state that 

 the injury was very severe. 



These citations are enough to show that 

 the disease is of special economic import- 

 ance and greatly dreaded by many fruit 

 growers. 



Symptoms. — (See Fig. 2753). The first 

 indication of fire blight is seen either in the 

 browning and subsequent blackening of the 

 leaves or of the young twigs or of young 

 tender shoots. When the twigs or shoots 

 are the principal parts affected the disease is 

 spoken of as twig blight. Pears show the 

 presence of the disease more frequently by 

 the blighting and blackening of the leafy 

 tufts of the spurs, and show it especially by 

 the darkening of the blossom clusters on the 

 larger branches; while later, the branches 

 themselves become blackened. The pro- 



FiG. 2753. A Blighted Orchard. 



gress of the disease is always downward, an 

 inch or more each day, depending upon the 

 season, until the larger limbs are infected. 

 In the more susceptible varieties it spreads 

 more quickly, involving the whole tree, but 

 in the more resistant varieties the progress 

 of the disease is not so fast. When the dis- 

 ease is active the bark of the diseased 

 branches cracks and a thick, blackish, gum- 

 my fluid exudes, and later the affected bark 

 becomes hardened, dry and shrunken. The 

 disease occasionally appears on the larger 

 branches and trunks of fruit trees when 

 these have been bruised or otherwise in- 

 jured, when its appearance is similar to the 

 injury known as " sun burn " or " sun 

 scald." This disease of the trunks or larger 

 branches is sometimes spoken of as " body 

 blight " or " rough bark." The inner bark 

 and cambium layer of the limbs and trunk 

 are the most important parts of the tree 

 killed by the blight. Instances are known 



