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STATE BOARD OF AGRICULTURE. 



The blight makes its appearance early in the spring shortly after the blossoms 

 have fallen and working rapidly back from the blossom clusters, an inch or 

 more a day, soon involves the tender succulent twigs and ultimately the whole 

 limb. If the diseased w-ood be cut off with a sharp knife, a dark ring between 

 the bark and the wood will usually be seen. This is a further indication that 

 your tree is affected. As the disease progresses and the smaller limbs show 

 the infection, the bark cracks and a thick, black, sticky gum exudes; soon after- 

 wards the bark becomes dark colored, hardened and shrunken. When the leaves 

 fall in the autumn, the diseased parts of the tree are left very conspicuous by 

 the dead leaves hanging to the twigs. If the blight attacks the larger branches 



Fig. 2. — Pear Twigs. The upper one shows the smooth b.irk of a healthy twig. In the lower one 

 note the dried up, shrivelled appearance caused by the Blight. 



and trunk where there has been some mechanical injury or bruise, the symptoms 

 are. much the same as what is known as sun burn or sun scald. This form of 

 the blight is known as rough bark or body blight. 



In some of the most susceptible varieties, it is not uncommon to see the wholf 

 tree blighted in a phenomenally short time, sometimes within ten days. Occa- 

 sionally it assumes its most severe form just previous to the picking of the crop. 

 The writer has one pear orchard in mind numbering some four hundred trees 

 which showed but three or four badly infected ones up to the middle of August, 

 1904, but within three weeks after that, every tree in the orchard was suffering 

 from a severe attack. The fruit had to be picked two weeks before time in order 

 to prevent all from being ruined by the blight. 



HISTORY. 



The disease is by no means recent for it dates back to the time of William 

 Denning who first reported the trouble from the Highlands of the Hudson in 



