XIII. A, 5 Reinking: Philippine Economic-Plant Diseases 231 



POWDERY mildew: erysiphaceae 



Symptoms. — A powdery mildew may be produced on the sur- 

 face of leaves of Phaseolus mungo Linn. Little damage is done. 



Causal organism. — Conidia and conidiophores of the Erysi- 

 phaceae type are produced. No perfect stage has been observed. 



Control. — Rotation of crops. 



rust: uromyces appendiculatus (pers.) unk 



Symptoms. — This rust is commonly found on Phaseolus mungo 

 Linn. Minute, slightly powdery, raised brovmish pustules are 

 produced on the lower surface of the leaves. The disease is 

 not often serious, but may cause the loss of a considerable amount 

 of foliage. 



Caudal organism. — Brown uredospores and black teleutospores 

 are produced in the sori. 



Control. — Crop rotation should be practiced. 



SOOTY MOLD 



Symptoms. — Frequently Phaseolus calcaratu^ Roxb. as well 

 as other beans may be covered with a black mold. The fungus 

 is superficial and does little damage. It grows on the exudate 

 of aphids. 



Causal organism. — The organism has not been identified. 



Control. — No special control need be practiced, since the 

 disease is not serious. 



Other fungi of more or less importance have been observed 

 on beans. On the ripened pods of Phaseolus vulgaris Linn, 

 are found Diplodia phaseolina Sacc. and Asteroma phaseoli Brun. 

 Phaseolus lunatus Linn, may be attacked just at the time of 

 maturity by two fungi — Cladosporium herbarum (Pers.) Lk. 

 and Diplodia phaseolina Sacc. 



PIPER BETLE LINN. ICMO, BETEL PEPPER 



On dead leaves of Piper betle Linn, may be found Oospora 

 perpusilla Sacc. 



PISUM SATIVUM LINN. PEA 



POWDERY mildew : ERYSIPHACEAE 



Symptoms. — The powdery mildew may be very destructive, 

 covering leaves, stems, and fruit. It is similar to that discussed 

 under tomato. 



Causal organism. — As yet no perfect stage of the fungus has 

 been observed. Conidia and conidiophores are produced in 

 abundance as on tomato. 



