34 NEBRASKA STATE HORTICULTURAL SOCIETY. 



Blight. When the twigs are blighted the leaves die, hence it is com- 

 monly said that the leaves are blighted, although usually the trouble 

 is in the twigs. See the discussion of Blight by Mr. Woods under 

 41 Diseases of Branches and Twigs," on preceding pages of this paper. 



DISEASES OF THE FLOWERS. 



Blight. It frequently happens that the flowers of the apple sud- 

 denly wither and turn brown with no apparent cause, no insects what- 

 ever being present. An examination of a good many specimens from 

 orchards within the state, as well as from without, shows that we 

 have here a case of genuine blight produced by bacteria identical 

 with those in the twigs. See the discussion of Blight by Mr. Woods 

 under "Diseases of Branches and Twigs," on preceding pages of this 

 paper. 



DISEASES OF THE FRUIT. 



Scab. But few apples are entirely free from this disease. In its 

 mildest form it produces little black specks on the skin, which do lit- 

 tle or no harm, but when more virulent it forms large black patches 

 and produces much distortion. The fungus which causes scab is 

 composed of dark-colored, jointed, branching threads which creep over 

 the surface, invading the superficial cells (Fig. 7). After the growth 

 has continued for some time, if the conditions have been favorable, 

 the fungus forms denser black patches in which it produces great 

 numbers of spores (Fig. 8). The particular manner of growth of 

 these spores is shown in Fig. 8, at B, and a few of the detached spores 

 are shown at S. When this fungus makes good progress in its growth 

 while the apple is still small it produces great distortion, but if its 

 development is later the apple is but little changed in shape, as in 

 Pig. 8. 



The fungus is one of the so-called " Imperfect Fungi," and is 

 known in science by the name of Fusidadium dendriticum. As stated 

 above (under "Diseases of the Leaves") it is the same one which at- 

 tacks the leaves. It lives perennially upon the bark of the twigs, and 

 from these it easily passes to the leaves and young fruit. Infection 

 takes place also through the growth of the spores, hence the burning of 

 the leaves in the fall would be useful. 



Professor Alwood, of Virginia, recommends spraying the trees in 



