II— PINEAPPLE ROT CAUSED BY THIELAYIOPSIS 



PARADOXA. 



By Flora W. Patterson, Mycologist, and Vera K. Charles and Frank J. Veih- 

 meyer. Scientific Assistants. 



INTRODUCTION. 



For >ome years Thielaviopsis paradoxa (De Seyn.) V. Hohn. has 

 been recognized as the cause of a serious rot of pineapples. Since 

 the species is not peculiar to this host or geographically restricted, 

 the necessity of some method of controlling the fungus is very urgent. 

 The present investigations of pineapple rot and the methods of check- 

 ing the disease by using formaldehyde gas were undertaken by the 

 Bureau of Plant Industry at the request of the director of the 

 Hawaii Agricultural Experiment Station. The object of the study 

 was to determine the death point of the fungus in the presence of 

 the gas and from this information ascertain what the practical appli- 

 cation might be to the pineapple industry. 



SYNONYMY OF THE FUNGUS. 



The synonymy of the fungus Thielaviopsis paradoxa is somewhat 



complex. It was described in 1886 by De Seynes fl as occurring on 

 pineapple and designated Sporoschisma paradoxum. In l^'l Sac- 

 cardo 6 referred it to Gkalara paradoxa ( De Seyn.) Sacc. Went* in 

 1893 described a fungus causing a serious loss to the pineapple 

 growers in Java and named it Thielaviopsis ethaceticus. Von 

 Hohnel* later, in 1904. called attention to the identity of the two and 

 included both under the name Thielaviopsis paradoxa . thus recog- 

 nizing in the acceptance of the generic name the proper systematic 

 position of the fungus and the rule of priority in the retention of the 

 specific name. 



a De Seynes. Reeherches pour servir a 1'histoire naturelle des vegetaux in- 

 ferieurs, III, 1886, pt. 1, p. 30. 



6 Saccardo. Sylloge Fungorum. vol. 10, 1892, p. 595. 



c Went. F. A. F. C. De Ananasziekte van bet Suikerriet. Mededeelingen 

 van net Proef station voor Suikerriet in West-Java te Kagok-Tegal. 1893. 



d Von Hohnel. Hedwigia. vol. 43. 1904, p. 295. 



34144— Bui. 171—10 2 15 



