xni, A, 5 Reinking: Philippine Economic-Plant Diseases 



237 



ROOT galls: nematodes: heterodera radicicola greef et muller 



Symptoms. — Root galls formed by nematodes are found, but 

 little damage has been reported. The galls produced are similar 

 to those discussed under tobacco. 



ROOT parasite: AEGINETIA INDICA LINNAEUS 



' Symptoms. — This flowering plant, one of the broom rapes, 

 may cause destruction of cane. The plant is a root parasite, 

 sapping the vitality of the sugar cane. 



RUST: PUCCINIA KUEHNII (KRUEG.) BUTLER [UREDO KUEHNII (KRUEG.) 

 WAKK. ET WENT.] 



Sym,ptoms. — This rust may be abundant on the leaves of sugar 

 cane and cause damage by lowering the vitality of the plants. 

 Sori are produced in greatest numbers at the base of the leaf 

 blade near the ligule, but sori may be produced on any part 

 of the leaf blade and on either 

 side. Characteristic bursted, 

 slender, brownish rust pustules 

 from 2 to 5 millimeters in length 

 are produced (Plate XVI, fig. 3) . 



Causal organism.. — The spores 

 are produced in groups under- 

 neath the epidermis, which later 

 bursts, due to the growth of 

 spores. The uredospores are 

 produced in abundance. They 

 are large, more or less ovate, 

 yellowish and with numerous 

 thick spines. Germination takes 

 place readily in water over- 

 night (fig. 31). 



Control. — General sanitation and cultural methods will keep 

 this disease at a minimum, 



SEREH DISEASE 



Symptoms. — This serious cane disease seems to have made 

 its appearance in the Philippines, and great care should be 

 exercised that it does not spread. The symptoms vary according 

 to the stage of the disease, and have been fully described in Java ; 

 the same characters are present in the Philippines. 



Plants slightly attacked show little or no external disease 

 characters. In some cases the internodes at the top of the plants 

 are somewhat shortened. The internal characteristics are a 



Puccinia kuehnii (Krueg.) Butl. 

 a, uredospores (X 320) ; b, 

 trermlnating uredospores (X 

 320). 



