spEciAi. re;port for year. 45 



in the vicinity of the red cedar. It is one of the diseases which 

 require the presence of two different or alternate hosts for the 

 development of the fungus which produces it. This fact is 

 the key to the situation with respect to the method of control. 

 If red cedars are removed it is easily eliminated as it is abso- 

 lutely essential that the fungus pass one stage of its life history 

 upon this tree to be able to re-infect the apple. Recently it 

 has been found, particularly in Wisconsin and West Virginia 

 that lime-sulphur is quite effective in controlling apple rust if 

 applied at the proper time in the spring. However, unless it is 

 impossible to eradicate the red cedar trees in the vicinity of the 

 orchard lime-suJphur should not be relied on wholly in controll- 

 ing the disease. Also from what has already been said it is 

 evident that apple rust need not be feared in those sections of 

 Maine where the red cedar does not occur. 



The quince is also attacked with the same disease, and 'n 

 Maine appears to be far more susceptible to it than the apple. 

 In fact quince rust is a disease which appears to occur in Maine 

 with a frequency which is far out of proportion to the extent 

 that its host plant is cultivated in the state. Several specimens 

 were sent in during the past season. It attacks the leaves, the 

 limbs, and the fruit of the quince, but it is on the last two that 

 it does the most damage. The affected limbs show swollen 01 

 enlarged sections an inch or more in length, not unlike the 

 black knot of plums in shape, but quite different in color. 

 These enlarged portions of the small limbs and twigs are cov- 

 ered with small pustules, and the latter often show feathery 

 projections around the openings. They are quite noticeable 

 when the spores begin to form as the liberation of the latter 

 gives the surface a bright salmon color. Most of the specimens 

 of diseased fruits which have been received by this Station were 

 quite severely attacked by the fungus. They were frequently 

 distorted in shape, and usually covered with the fruiting pus- 

 tules which showed many of the feathery cylindrical projections 

 which when broken have a fimbriate margin. On account of 

 the liberation of millions of bright colored spores upon the 

 surface of such fruit the diseased portion is of a salmon or 

 even orange color. 



Early in the spring, almost before the growing season has 

 begun, the other stage of the quince or apple rust occurs on the 



