86 



QUINCE CULTURE. 



more or less protected by a coating of natural varnish, sup- 

 posed to be wax or silica. Whatever it may be, it is best 

 to observe what soils and fertilizers supply it. Ashes and 

 lime are found to improve the quality of fruit, and it 

 may be assumed, also, that they increase the vigor of 

 growth, and so aid in resisting the attacks of bacterial 

 and fungoid diseases. 



2. OEANGE BUST (Rcestilia aurantiaca, Peck; Cen- 

 tridium Cydonice, Ellis). This fungus affects the stems 

 and fruit of the quince in June and onward. In a single 



Fig. 56. STEM AT A BUD AS AFFECTED BY THE R.ESTILIA AUEANTIACA. 



instance I have seen it on the leaf stalk. The spores 

 are of a beautiful orange color, globose in shape, with a 

 membranous envelope, and are produced in sacks or 

 pustules, which form an enlargement on the stems, re- 

 sembling the black knot of plum and cherry trees. The 

 little blackened quinces remaining on the trees after 

 the leaves have fallen, attest its destruction of the fruit, 

 and warn us against its neglect. Once in a while a stem 

 survives its attacks, and so of the fruit. As the disease 

 progresses the granules burst, forcing their sides upward, 



