Some Important Pear Diseases. 



:85 



The mycelium, or vegetative threads, of the fungus penetrate the 

 epidermal layer, and to some extent the general tissue of the leaf, 

 breaking down the cells consider- 

 ably in that region of the leaf show- 

 ing the spot. 



With proper conditions these 

 spores germinate readily, and ulti- 

 mately produce again the spot 

 wherever they secure an entrance 

 into the tissues of the leaf. Sorauer 

 claims that from the germination 

 of the spore to the appearance ot 

 mature spores in the spot it may 

 induce, about one month is re- 

 quired.* 



3. Occurrence in the Orchard 

 AND Remedies.! 



The leaf-blight has proved a pest 

 to orchardists throughout the coun- 

 try, yet it has been less injurious in 

 New York than in many states 

 farther south and west. I find it 

 more abundant in the Hudson 

 Valley than in other sections ot 

 New York. It seems to attack 



quite generally the varieties more commonly cultivated, although 

 Duchess and KiefTer have often been reported resistant. Many 

 varieties in one place reported free from the disease are reported 

 badly injured in other sections. 



167. — Pear injured by the leaf-blight 

 fungus, showing no indication 

 of cracking. 



*NoTE. — Sorauer has described at length a winter form or perfect stage 

 of the Entoinosporiu)n which he has called Stigniatea inespili. On wintered 

 leaves of quince Professor Atkinson has also found this fungus, and he has 

 suggested referring it to the discomycetous genus Fabrcea. See Garden 

 and Forest, 1. c. 



f It is to be noted that in this connection we can refer to the results only 

 as published, but owing to the comparative abundance of the leaf-spot in a 

 few eastern states where the leaf-blight only has been reported upon, there 

 is danger that some important mistakes have been made. 



