214 The Philippine Journal of Science isis 



Causal 07-ganism. — The organisms causing the trouble in the 

 Philippines have not been studied. In the Federated Malay 

 States the following common saprophytic fungi have been as- 

 signed as the cause : Penicillium -maculans sp. n., Fvsarium, Chro- 

 mosporium crustaceum sp. n., Trichoderma koningi (Oud.) 

 Oudemans et Koning, Eurotium candidum Speg., and Bacillus 

 prodigiosus (Ehrenb.) Fluegge. Oil and dirt are other sources 

 of discoloration. The latex becomes primarily infected in the 

 field due to improper field cultural methods, the use of contami- 

 nated water for washing out jars, and to contaminated pails. 



Control. — Ordinary sanitary measures are sufficient for control. 

 General cleanliness in tapping, collecting of latex, and prepara- 

 tion of rubber should be observed. The plantation should be 

 kept free from all dead decaying matter which harbors sapro- 

 phytes. The pails used for the collection of latex should be 

 thoroughly scalded after using each day. Water used in cleaning 

 the cups should be obtained from a source free from contamina- 

 tion. Collectors should never be allowed to obtain water for 

 washing from contaminated streams. The factory and drying 

 shed should be constructed according to the best accepted methods. 

 The drying sheds should be located in a well-aerated place so as 

 to provide for plenty of circulation, for rapid drying lessens 

 the chances of spotting. Thin crepe is less apt to become spotted, 

 due to its quicker drying. Spotted rubber should never be packed 

 with clean rubber. Usually these precautions are sufficient to 

 prevent the trouble. In severe cases of infection it is advisable 

 to sterilize the latex with 1 part of formalin to 400 parts of 

 latex. Lightly spotted rubber may be somewhat cleared by 

 rerolling the dried rubber and washing thoroughly with water. 



OTHER FUNGI 



A large number of apparently saprophytic organisms appear 

 on the dead branches of Para rubber. Among these Tryhlidiella 

 mindanaensis Henn. and Eutypella heveae Yates have been iden- 

 tified. 



HIBISCUS SABDARIFFA LINN. ROSELLE 

 blight: phoma sabdariffae saccardo 

 Symptoms. — A stem blight that is rather severe on roselle, 

 often killing entire plants. Diseased stems are attacked chiefly 

 at the bases of small branches, at the nodes. Internodes also may 

 be attacked. The spots spread until they entirely encircle the 

 twigs. They are black with gray centers and are specked with 

 minute black bodies. The disease is most severe on nearly 

 matured plants. 



