222 



THE DISEASES OF FRUITS. 



Clairgeau are among the most susceptible, but fine crops of 

 fruit may be gathered of these sorts from trees that formerly 

 were worthless after thorough spraying has been adminis- 

 tered. 



It only needs to be said in passing that the blight folrage 

 and diseased fruit are sources of contagion, and the progres- 

 sive pear grower will see to it these are burned so far as prac- 

 ticable and thus reduce the number of germs of the disease. 

 There is an orchard sanitation as essential to good health of 

 trees as that which should obtain around the house for the 

 well-being of its inmates. 



Pear Scab (Fusicladium pirinum Fcl.) is a very conspicuous 

 fungus and one that is easily confused with the Entomosporium 



Fig. 283.— Microscopic view of a section through scab spot upon pear fruit 

 showing spores at j, erect tips at /, cuticle at c, epidermis at e, and corky cells 

 at*. (From Duggar.) 



previously treated, but under the microscope the appearance 

 is strikingly different. Instead of the compound spores of the 

 Entomosporium, which curiously resemble the form and vari- 

 ous body parts of an insect, and hence its generic name, the 

 Fusicladium has simple oval brown spores that are produced 

 singly upon the ends of short irregular threads (see Fig. 283). 

 The fungus, by means of a network of fine threads, makes a 

 firm attachment to the tissue of the fruit or leaf. The twigs 



