600 INSECTS AFFECTING VEGETATION 



interior of the stalk. Of course, the dipping of the ends is not prac- 

 ticable on a large scale on account of the expense involved. In order 

 to treat the cane on a large scale and to treat it rapidly, we must 

 have some solution in which the whole stalk can be placed, one 

 which will not kill the eyes of the cane but one which will prevent the 

 attack of the fungi. The only solution which we have at present 

 which approaches this requirement is Bordeaux Mixture. This is 

 a copper-lime compound which is very poisonous to fungi and will 

 not penetrate the eyes of the cane so as to hurt their germination. 

 The treatment of sugar cane cuttings with this solution is not only 

 practicable but? is highly profitable in tropical sugar countries. 

 Of course, special machinery and special tanks are used so that a 

 large amount of seed can be run through the solution in a short 

 time. Whether the treatment of the seed would be profitable to 

 the Louisiana planter in normal years is a question, but I am con- 

 vinced that it would be profitable during a dry season. And if the 

 pineapple disease spreads over the state and does as much damage as 

 it does in the tropics, the treatment of the seed will not only be profit- 

 able but it may become a necessity. (La. E. S. B. 120.) 



The Root Rot Disease. The root rot disease has been well 

 treated in Bulletin 100 of the Louisiana Station and only a few 

 points need be mentioned here. The disease is caused by one of the 

 higher fungi, one of the mushrooms, known to botanists as Maras- 

 mius plicatus. This disease attacks both the cuttings and the grow- 

 ing cane. On the growing cane, it kills the roots and grows in 

 between the lower leaf sheaths. The leaf sheaths are not shed as 

 is the case with healthy cane, but remain glued together around the 

 stalk. If some of these are pulled apart, a network of white my- 

 celium will be seen between them. In August, or perhaps during 

 others seasons, if the weather conditions are suitable, the little 

 mushrooms, the fruiting part of the fungus, develop on these leaf 

 sheaths. 



On the cane which is used for seed, this disease will also de- 

 velop. I have seen it to some extent in nearly every batch of cane 

 which has been sent me this year. The mycelium enters the cut 

 ends of the stalks and grows through them. The disease is readily 

 told by the presence of the white strands of mycelium which may be 

 on or in the stalks. Sometimes the eye is killed before germina- 

 tion, and sometimes the young plant is killed after germination. 



This disease is widely distributed in the state and probably has 

 been for a long time. In some places it does considerable damage, 

 but in normal years the loss has not been large. This year it has 

 caused considerable loss both in the plant cane and in the stubble. 

 The dry weather has put the cane in a more or less unhealthy con- 

 dition and the cane has been very susceptible to the disease. 



Other Cane Rots. While the fungi causing the four diseases 

 previously discussed w r ere the most frequent and the most prominent 

 in the cane cuttings that were received, there were some other organ- 

 isms present which undoubtedly rotted some of the cane and should 

 be studied further. As it is the intention of the station to continue 



