134 MANUAL OF FRUIT DISEASES 



protrudes. Certain hyphse grow erect and parallel to each 

 other; these are the conidiophores. On the tip of each stalk 

 a conidium is borne. From a single fruiting body several 

 hundred spores may be produced. These are scattered to 

 other fruits and thus new infections arise. Intermingled with 

 the conidiophores are dark-brown, hair-like spines called setae. 

 So far as known the setae play no part in the propagation of the 

 fungus. They serve, however, to distinguish this pathogene on 

 the apple. It is as yet unknown where and in what condition 

 the pathogene passes the winter. The assumption is, that it 

 lives vegetatively in fallen fruits and possibly on decaying 

 debris of various kinds. Infection does not occur, apparently, 

 before the late summer. Lesions develop most commonly on 

 fallen and stored fruits. The disease seems to be highly favored 

 by conditions that prevail in an uncultivated orchard where the 

 weeds and grass abound ; here plenty of moisture is available 

 to the parasite. 



Control. 



In the absence of experimental data little can be recommended 

 for the control of the spongy dry-rot. The disease is not widely 

 destructive and in even those regions where it is most serious 

 it is doubtful whether special treatment is necessary to satis- 

 factory control. Fruit in orchards that are given the standard 

 care may be expected to suffer but little from this disease. 



REFERENCES 



Stevens, F. L., and Hall, J. G. Some apple diseases. The Volutella 

 rot. North Carolina Agr. Exp. Sta. Bui. 196 : 41-48. 1907. 



Smith, R. I., and Stevens, F. L. Insect and fungous diseases of apple 

 and pear. Volutella rot. North Carolina Agr. Exp. Sta. Bui. 

 206 : 104-107. 1910. 



Stevens, F. L., and Hall, J. G. An apple rot due to Volutella. Journ. 

 Myc. 13 : 94-99. 1907. 



Duggar, B. M. Spongy dry rot fungus of apple. In Fungous Dis- 

 eases of Plants, p. 316. 1909. 



