358 MAINE AGRICbLTURAL EXPERIMENT STATION. I9IO. 



mixture or lime-sulphur gave good results in the control of the 

 spot if applied at the same time or a little later than for the con- 

 trol of apple scab. 



This disease is of common occurrence in Maine and it does 

 considerable damage by injuring the appearance of fruit. Fruit 

 growers should become familiar with the disease and make ef- 

 forts to prevent the loss which it causes by reducing the price 

 which they receive for their apples. 



Sooty blotch and Fly speck of the fniit. These diseases take 

 their names from the appearance which the growth of the fungus 

 gives to the fruit. Both are now regarded by certain writers* 

 as caused by the same fungus, Lcptothyrium pomi (Mont. & 

 Fr.) Sacc. The fungus does not penetrate into the apple. In 

 the case of sooty blotch, the mycelium spreads over the surface 

 covering areas which vary in size and sometimes practically the 

 whole apple is covered in bad attacks. Fig. 249 is a photograph 

 of an apple affected with sooty blotch. Fly speck is character- 

 ized by the development of black shining bodies composed of 

 fungous threads closely woven together, which occur in patches 

 on the surface of the apple. 



The chief loss caused by these diseases is in injuring the ap- 

 pearance of fruit and thereby lowering its market value. Neither 

 sooty blotch nor fly speck is of so common occurrence in i\laine 

 as they are farther south. Where thorough spraying is done, 

 these diseases are effectually controlled. 



Sphaeropsis leaf spot. Leaf spot is a common and widely 

 distributed disease of the apple in Maine. With some varieties 

 and under certain weather conditions a spotting of the leaves is 

 caused by spray injury, see p. 348. It is a matter of common 

 observation, however, that orchards or trees which have never 

 been sprayed are often affected with a spotting of the leaves 

 which in some cases is quite serious. 



Affected leaves show little spots of dead tissue, usually some- 

 what circular in outline. The dead portion is not qiu'te so thick 

 as the surrounding green tissue and takes on a brown color. 

 On the dead spots little black bodies are frequently found which 

 are the fruiting portions of the fungi associated with the spots. 

 The dead spots often show concentric rings. 



* Duggar, B. M. Fungous Diseases of Plants, p. 367. 1909, 



