597 



dening of the tissue. This red, however, is usually intensified if the 

 red rot is also present. Frequently in this cane also, the disease may 

 be diagnosed by the presence of the white spots. But to make abso- 

 lutely certain as to the presence of red rot in borer cane, cultures 

 from the diseased tissues must be made or else the split canes be 

 placed in a moist place and the fungus allowed to develop on the cut 

 surface. The fungus frequently gains entrance to the cane through 

 borer holes, but these openings do not appear to be essential. 



The damage which is done by the red rot occurs in two forms. 

 Canes that are affected with the disease have the sugar content, es- 

 pecially the sucrose, very much decreased. As the value of the crop 

 depends upon the amount of sugar in the stalks, the decrease due to 

 the disease becomes very important. Analyses that have been made 

 in Java, Bengal and the Hawaiian Islands show that the saccharose 

 content is decreased by from 1/4 to 1/3 by the action of the fungus. 

 Consequently a severe attack of the disease means a big loss to the 

 crop. The fungus grows in the stalks that are to be used for planting 

 and kills the eyes, thus preventing germination and causing a 

 poor stand. This seems to be the worse of the two injuries at 

 present in Louisiana. But a poor stand means a short crop with 

 no profits. 



The treatment of the disease should be conducted in two ways 

 First, all material in the field known to be diseased should be 

 destroyed, and, Second, the cane to be used for planting should 

 be as carefully selected as possible. As the fungus does not fruit 

 to a very great extent, it does not spread very fast in the field. If 

 perfectly healthy canes were planted each time, the disease would 

 cause but little damage. However, when diseased cane is planted, 

 the disease spreads upwards into the young stalks and the eradica- 

 tion of the trouble is impossible. The most desirable thing would 

 be to select carefully all the cane to be used for planting, throwing 

 out any that show any external signs of disease or any that are 

 attacked by borers. This method of selection would, however, hardly 

 be profitable on account of the large amount of time it would take 

 to select the seed. (La. E. S. B. 120.) 



The Pineapple Disease of Cane. The pineapple disease is 

 perhaps the most serious of all the sugar cane diseases. The trou- 

 ble is widely distributed in all the sugar-growing countries of the 

 tropics and in all cases does a large amount of damage. Previous 

 to this, however, we have not had the disease to contend with in 

 Louisiana, as it has now just appeared in the state. It is not known 

 to occur in any other state, and is only known to be present in 

 one parish in Louisiana. But there is a strong likelihood of it de- 

 veloping rapidly and spreading to other parts of the state. The 

 presence of this disease in the state is indeed a very serious matter. 

 Of course, there is a small chance that the fungus will not be ablo 

 to stand our winters and therefore will be of little economic im- 

 portance, but such good luck as this can hardly be hoped for. The 

 wisest course for the Louisiana sugar planter is to be prepared for 



