DISEASES OF SPECIAL CROPS 



113 



has not yet been proved that this fungus causes cankers 

 on the quince trees such as have been described for the 



Fig. 48. — Black spot of the quince, natural size. After Bailey. 



apple. The grower should, however, watch carefully for 

 the presence of canker, as the relation between the canker 

 and the rot in apple indicates that the canker may possibly 

 be found on the quince also. 



