xiii. A. 5 Reinking: Philippine Economic-Plant Diseases 2t'i\. 



Caitsal organism. — The blackish dust in the center of the 

 gray is made up of conidiophores and conidia. Conidiophores 

 are produced in groups ; they are septate and light brown. The 

 conidia are typical Cercospora spores, hyaline, tapering, and 

 much elongated, often being ten-celled. 



Control. — The disease may be controlled by ordinary crop 

 rotation. 



POWDERY mildew: erysiphaceae 



Symptoms. — During the cool season of the year leaves may 

 be attacked by a powdery mildew. The upper, and sometimes 

 the lower, surface of the leaf presents the characteristic powdery 

 appearance. 



Causal organism. — Conidiophores and conidia of the Erysipha- 

 ceae type are produced in abundance. No perithecia and asci 

 with ascospores have been observed. 



Control. — The disease is seldom serious enough to warrant 

 any special control. In severe cases of infection, dusting with 

 sulphur or spraying with any standard fungicide will control 

 the fungus. 



Other fungi found on dead and dying stems are Phoma sesa- 

 mina Sacc, Gloeosporium mucrophomoides Sacc, Vermicularia 

 sesamina Sacc, and Helminthosporium sesameum Sacc. 



SOLANUM MELONGENA LINN. EGG PLANT 



BACTERIAL WILT: BACILLUS SOLANACEARUM ERW. SMITH 



Symptoms. — This bacterial wilt is common on all solanaceous 

 plants in the Philippines. It is often the limiting factor in 

 the production of eggplants. The disease is similar to that 

 of tomato and is more fully described under that heading. 



LEAF SPOT AND FRUIT ROT: GLOEOSPORIUM MELONGENAE SACCARDO 



Symptoms. — This disease is found upon the leaf and fruit. 

 On the leaf the characteristic irregular spots with brownish 

 gray centers bordered with dark brown are formed (Plate XVIII, 

 fig. 1). Within the center of spots, in the brownish gray, are 

 produced numerous minute black specks, the fruiting bodies of 

 the fungus. Diseased fruits have large, irregular, sunken light 

 brown areas bordered with a darker brownish ring. Within 

 these sunken spots black specks are produced in large numbers. 

 Fruits may be entirely rotted, due to the attacks of the fungus 

 (Plate XVIII, fig. 3). The disease is most severe during the 

 rainy season. 



