58 STATE POMOLOGICAL SOCIETY. 



SOME PRACTICAL APPLICATIONS. 



1. Apple Scab. 



I doubt not most of you are familiar with the dark colored spots 

 or "scabs" which appear ou some varieties of apples — notably 

 Fameuse, Maiden's Blush, and Golden Pippin. These spots repre- 

 sent but one stage in the life history of one of the parasitic fungi 

 already referred to, {Fusidadiam dendriticum.) 



The disease appears on the leaves, usually on the under side, as 

 brownish or olive colored spots. These spots if numerous run 

 together, become blackish in color and finally the leaf tissue dies. 

 In cool wet weather the fungus often spreads very rapidly and, 

 attacking the foliage and young fruit early in the season, causes 

 almost total loss of crop and greatly weakens the trees. The 

 leaves are both lungs and stomach of the plant, and any check to 

 these organs must seriously affect the vitality of the tree. If the 

 attack is late, after the season's growth is completed, no special 

 damage is done except to injure the fruit. 



While the spots if recently developed do not directly injure an 

 apple for immediate use, they greatly affect its appearance and will 

 continue to grow and spread, and the fruit will decay much sooner 

 than if not affected. On the other hand, fruit attacked early in 

 the season will either fall prematurely, or will be deformed and 

 cracked, the parasite utilizing all of the materials for growth on 

 the side affected. 



For several years I have conducted careful experiments with the 

 hope of arriving at definite conclusions concerning the use of cer- 

 tain chemicals as preventives of the disease in question. As a 

 result of this work I feel safe in asserting that we may to a large 

 extent control the attacks of the apple scab by the use of the 

 Bordeaux mixture already described. 



In almost every instance where comparisons have been made 

 there has been a marked difference in favor of the sprayed trees — 

 the gain in the per cent of fruit free from scab amounting, in many 

 cases, to more than half of the crop. 



The accompanying table shows very clearly the results obtained 

 last year. 



