238 The Philippine Journal of Science i9i8 



reddening of the fibrovascular bundles that arise from the leaf 

 sheaths at the nodes and a gumming of these bundles, which 

 can be observed only under the microscope. The reddening may 

 extend for some distance down the cane. 



A medium attack of the disease is characterized by a produc- 

 tion of many buds and sprouts from the upright stems. Such 

 plants have a more or less bushy appearance, due to the short- 

 ened internodes and the abnormal production of shoots. Dis- 

 eased stems are somewhat shorter than the normal ones. 

 Frequently a mass of adventitious roots is developed from the 

 nodes under the leaf sheaths. 



The worst stage of the disease is the most characteristic. Few 

 or no upright stems are produced in a field that is entirely 

 diseased. Other fields may have diseased plants scattered here 

 and there. This condition is due to the shortening of the in- 

 ternodes and a consequent lack of production of upright stems. 

 Leaves arising from these close nodes are necessarily produced 

 in a bunch and such a plant has the appearance of a fan. Shoots 

 also may arise from these diseased and stunted plants, which 

 make them appear like a bunchy grass. A grass in Java, Andro- 

 pogon schoenanthus Linn., called "sereh" is similar in appearance 

 to these diseased canes, consequently the name "sereh" has been 

 used for diseased cane. Severely diseased plants also may have 

 an abundance of adventitious roots produced from the nodes 

 under the leaf sheaths. 



In the Philippines the disease has been observed to be more 

 abundant in ratoon fields. It is often spread by cuttings. Cut- 

 tings of a plant showing only the first symptoms of the disease 

 will produce plants that exhibit the disease in its medium stage. 

 Cuttings from plants with' medium attacks produce plants that 

 show the severe case of disease. The disease may in this way 

 become more and more severe. 



Causal organism. — Investigation of this trouble has just been 

 started in the Philippines. As yet no organism has been as- 

 sociated with the disease in other countries. In some cases it 

 appears that the disease is infectious, for it seems to spread. 

 It may be spread by planting cuttings from diseased plants, but 

 it has not been shown that a healthy plant can contract the 

 disease from a diseased plant. In Java the disease is assigned 

 to a deterioration of the cane. 



Control. — No cane should be imported from countries in which 

 the disease exists. Care should be taken that the disease is 

 not spread from infected plantations to noninfected ones. Cut- 



