364 Journal of Agricultural Research voi. xv.no. e 



two organisms do not cause storage-rots. However, another organism, 

 F. oxysporum, which might easily be mistaken for F. hataiatis but hardly 

 for F. hyperoxysporum, is one of the most common inhabitants of decayed 

 sweet potatoes. In most storage houses it is common to find potatoes 

 decayed at the end for a distance oi }4 to i]4 inches, the tissue being 

 brown and firm and emitting a pleasant aromatic odor (PI. 27, F). From 

 such decayed ends and from certain surface lesions and wounds F. oxy- 

 sporum is the most common species of Fusarium isolated with any degree 

 of regularity. Occasionally other fungi may be isolated, as, for example, 

 Plenodomus destrttens, Nectna ipomoeae, or F. orihoceras. Although 

 it is the belief of the writers that F. oxysporum does cause an endrot of 

 stored sweet potatoes we have consistently failed to obtain proof of it 

 by any of the methods employed. 



Nectria ipomoeae Hals, is another fungus frequently found on decayed 

 sweet potatoes. It was first thought by Halsted to be the cause of the 

 stemrot of sweet potato and eggplant, but was later shown (22) to be 

 only a saprophyte. Since it was frequently isolated from rotted sweet 

 potatoes, N. ipomoeae was suspected of causing a storage-rot, but like 

 many of the other organisms studied, it consistently failed to give 

 positive results by any of the methods tried. 



Fusarium caudatum is not a common inhabitant of decayed sweet 

 potatoes. It was originally isolated from a number of sweet potatoes 

 sent trom Clemson, S. C, by Prof. H. W. Barre. Prof. Barre said that 

 several hundred bushels had been thrown out of a storage house similarly 

 decayed. The decayed potatoes were brown in color, firm in texture, 

 and had a very pleasing aromatic odor. We were unable by any of the 

 methods tried to prove this organism the cause of a storage rot. None 

 of the other forms with the exception of F. radicicola are very common. 

 This species of Fusarium was frequently isolated from decayed potatoes 

 and from the wounds and lesions of field material, especially from the 

 South. However, in our experiments it has given no evidence of being 

 a storage-rot producer. It is a common soil saprophyte and probably a 

 secondary invader. 



At different times other fungi have been isolated with which no experi- 

 ments have been conducted. They were so rarely met with that inocu- 

 lation experiments did not seem justified. Among others the following 

 may be mentioned: Zygorhynchtis sp., Penicillium sp., Melanospora sp., 

 Trichosporium sp., Ceratostoma sp., Sporotrichium sp., Pestalozzia sp., 

 Aspergillus niger Von Tiegh, Sclerotiurn roljsii Sacc, F. vasinjectum 

 Atk., Cephalothecium, sp., Neocosm,ospora vasinjectum Atk,., Verticillium 

 cinnabar inus , Acromoniella sp., Macrosporiutn sp., Actinomyces sp., and 

 others. 



