240 '^he Philippine Journal of Science i9i8 



destroyed, for the disease spreads from wild to cultivated cane. 

 Only cuttings from healthy plants should be used. In severe 

 cases of infection crop rotation will have to be practiced. 



SOOTY mold: meliola arundinis patouillakd 



Symptoms. — Leaves and even whole plants of sugar cane may 

 be frequently covered with a superficial black mold. This mold 

 is produced on the sugary excretion produced by aphids and 

 mealy bugs. The fungus is not parasitic, but causes some 

 damage by shading the chlorophyll of the leaves, thereby reduc- 

 ing their full working capacity. 



Causal organisTn. — The mycelium is dark brown with charac- 

 teristic hyphopodia. The perithecia are produced among the 

 mycelial strands, and within the perithecia are globular, hyaline 

 asci with brown septate ascospores. 



Control. — The control of aphids and mealy bugs will entirely 

 check this disease. 



STEM rot: bacterial 



Symptoms. — Young weakened cane may rot from the tip of 

 the stem downward. The disease is only present in poorly kept 

 plantings and seems to be most prevalent on the ratoon cane. 

 It appears to be due to bacteria. 



Other fungi found on weakened and dead leaves are Coniospo- 

 rium vinosum (B. et C.) Sacc, Coniosporium extremorum Syd. 

 Apiospora camptospora Penz. et Sacc, Melanconium lineo- 

 latum Sacc. and Haplosporella melanconioides Sacc, forma, are 

 found on dead stalks of cultivated cane. Haplosporella melan- 

 conioides Sacc. is found on dead stalks of wild cane. 



SESAMUM INDICUM LINN. SESAME, LINGA 



leaf spot: CERCOSPORA SESAMI a. ZIMMERMAN 



Symptoms. — A common and destructive spot-producing fun- 

 gus, affecting leaf, petiole, stem, and capsules. Spots are scat- 

 tered over the leaf surface and are from 1 to 4 centimeters in 

 diameter. They are irregularly circular, and have gray centers, 

 bordered with brownish to purplish rings. Frequently older 

 spots may have concentric rings .of purplish brown. Spots 

 often run together, until finally the entire leaf is covered with 

 a brownish blotch, with the gray-centered spots bordered with 

 purplish scattered through the brown. The spots on petiole and 

 stem are similar to those on the leaf, except that they are 

 somewhat more elongated and slightly sunken. Spots on the 

 capsule are usually distinctly circular and are sunken and have 

 gray centers bordered with brown. 



