468 INSECTS AFFECTING VEGETATION 



of the fruit. It occurs practically wherever the pear is cultivated. It 

 was mentiqned in this country early in the sixties. The prominent 

 symptoms are the premature discoloration of the leaves and their 

 falling off together with the frequent cracking of the fruit. This 

 leaf fall may be sudden or more gradual, extending in the latter case 

 throughout the growing season. Often the leaf fall is accompanied 

 with a second blossoming both together making a rather severe 

 drain upon the food supplies of the tree. 



Small reddish spots are first seen upon the leaves; these spots 

 as they increase in size take upon themselves a more definite circular 

 shape. At maturity the spots are provided wdth a white to reddish 

 brown center and a darker raised border. The spots may unite wdth 

 each other and thus the whole leaf may become affected. The spots 

 may come to be seated upon a reddish brown discolored leaf or the 

 leaf may turn yellow. In any case the leaves fall from the tree. 



In many cases there is also a so-called cracking of the pear pro- 

 duced by the same fungus. Small reddish spots appear upon the 

 fruit and these spots may rapidly increase in number and finally 

 coalesce with one another to give the fruit a very much blotched ap- 

 pearance that will greatly reduce its market value. At the same 

 time the growth of the spots may be accompanied by a cracking of 

 the fruit and of course this cracking may make an entrance for the 

 spores of the rot fungi that may cause much damage. The same 

 fungus often attacks the young twigs of the pear. The spots upon 

 the green bark of these twigs are somewhat elongated, sunken and 

 of a black color. In each of the spots referred to above on either 

 the leaves, fruits or twigs one may see one or more blackish spots 

 just beneath the surface. These spots are the spore producing bodies 

 of the fungus. The petioles and leaf scales are also frequently at- 

 tacked. 



Fallen leaves should be gathered together and burned. The 

 disease may be controlled by spraying with Bordeaux mixture, as 

 follows : 



(1.) When leaves are half grown. 



(2.) Three subsequent sprayings at intervals of two weeks. 



The sprayings after the second should be made with an am- 

 moniacal copper carbonate to avoid the russeting-injury to the fruit 

 often produced by the Bordeaux mixture. 



Scab. The scab of pear is, like the similar disease of apple, 

 very widespread and well known. It is known from practically every 

 region where pears are grown. The symptoms are practically the 

 game as for the apple scab. This disease is due to the fungus called 

 Fusicladium pirinum. The diseased leaves should be plowed under 

 or else gathered together and burned during the fall. Two spray- 

 ings with Boreaux mixture of the 1-10 formula should be made 

 while the pear leaves are opening. Considerable good in controlling 

 pear scab will result from a spraying with the lime-sulphur-salt mix- 

 ture as late in the winter as possible. (Ala. E. S. 132.) 



Pear Scab. A scabby, corky growth in certain spots on the 

 surface, accompanied by a distortion or deformation of the mature 



