14 MAINE AGRICUI.TURAI, EXPERIMENT STATION. 



rot fungus. Also recent work done at this -Station has con- 

 firmed the conclusion arrived at by certain earlier investigators 

 that the true Baldwin spot is without doubt a physiological 

 trouble. This should be not confused with a somewhat similar 

 fruit spot of fungus origin sometimes occurring on Baldwins. 

 Investigations made in Maine indicate that the last named dis- 

 ease is much more common in this State on the Bellfiowers and 

 similar light skinned varieties, particularly native seedlings, 

 where the spots are a bright carmine with a brownish center 

 and in no way resemble Baldwin spot. 



Apple Scab. Since this is probably the most important apple 

 disease in Maine from an economic standpoint, it has received 

 special attention. This has been largely in the line of control 

 measures which are discussed under spraying. Several observa- 

 tions have been made, however, which are in a way contribu- 

 tions to our knowledge of this disease. Perhaps the most im- 

 portant of these is the fact that in this climate scab may some- 

 times, on certain- varieties, live over a winter in diseased branches 

 and become a source of spring infection the following year. 

 Much damage by scab was recorded during the summer of 

 1912 from injury to the young branches of actively growing 

 trees of susceptible varieties. It was shown conclusively that 

 In many instances the fungus remained alive over winter in 

 these branches and was a source of infection in the spring of 

 1913. A dormant spray of lime-sulphur proved to be quite 

 effective in controlling spring infection from this source. 



Evidence has been obtained which indicates that apple scab 

 may, if conditions are favorable, spread from diseased to healthy 

 fruit in storage. As has been observed in certain other states, 

 pink rot has been found to be very destructive upon apples 

 affected with scab. The fungus causing this decay apparently 

 is not able to attack apples with a sound skin. 



Apple Leaf Spot. Much attention has been given to apple 

 leaf-spot. Various fungi have been named as the cause of this 

 disease in different parts of the country, but an extended and 

 detailed investigation has shown conclusively that aside from the 

 similar appearing spots caused by sprays, the black-rot fungus 

 is the sole cause of leaf-spot in Maine. 



