1908.] Apple "Scab" or " Black Spot." 



" scab " produces isolated characteristic markings, which 

 give a " pocked " appearance to the wood. Severely attacked 

 young shoots may — as in the case of those of " Lord Sumeld," 

 shown in Fig. 7 — be " blistered " almost continuously over 

 the surface, and the bark will then subsequently peel off in 



4 



FIG 6. — The Apple Scab or "Black Spot " fungus attacking the young wood of 

 apples : — (A), on Cox's Orange Pippin: (a), healthy wood ; {b), diseased wood, the 

 blistered appearance being due to pustules of spores breaking through the bark. 

 (B), on Wellington : {c), healthy twig ; {d), twig with diseased patch below. 



flakes. I have known such attacks to be mistaken for " canker" 

 by growers. No " rot " or " canker " is caused by the, 

 " scab " fungus on the wood* ; the growth of the shoot, 

 however, is often much weakened. 



If a section of " scab "-diseased wood is cut across a 



* I have, however, frequently met with cases where the young wood has been 

 attacked by both "canker" and "scab" on one and the same shoot. It is not 

 improbable that the "canker" spores may find an entrance into the wood at places 

 where the bark has been ruptured by the " scab." 



