

WITCHES -BROOM OF BAMBOO. 9 



METHOD OF CHECKING THE DISEASE. 



This disease of sedge has been checked by careful cultural methods, 

 as shown in the following extract from a letter of July 2, 1909, 

 written by Mr. F. W. Clarke, Special Agent in Charge of Matting- 

 Rush Investigations, United States Department of Agriculture: 



I am in receipt of your letter of June 25, inquiring the present status of the 

 sedge disease that appeared at Pierce, Tex., and Jacksonboro, S. C, last year. 

 In answer would say that until June 24 I bad tbe sedge patcb under close 

 observation and failed to find anything but a very slight trace of the disease 

 that gave us so much trouble last season. What few diseased stalks I did find 

 were confined to a very small space, and these I cut off and burned. Of 

 course it is quite possible that it will appear in other parts of the field. How- 

 ever, it is my opinion that it will be impossible for it to do any material dam- 

 age, as in two or three weeks the crop will be ready to harvest. My observa- 

 tions last year led me to the conclusion that the disease spreads most rapidly 

 when the stalks are in a very succulent state. As this stage is passed, the stalks 

 having attained the proper length and having nothing to do but fill out, I do 

 not anticipate any danger from this source. At Jacksonboro, where the plants 

 did not get the careful attention that I gave them in Texas, I find that the 

 disease is very prevalent, at least 50 per cent of the stalks being affected. This, 

 in my opinion, points conclusively to the fact that by burning off the stubble 

 in the winter, thereby leaving the land perfectly bare, and by spraying with 

 Bordeaux mixture just as soon as the disease appears, should it appear, the 

 disease can be very readily controlled and possibly stamped out altogether. 



WITCHES'-BROOM OF BAMBOO CAUSED BY A NEWLY DISCOVERED 

 FUNGUS, LOCULISTROMA BAMBUSAE. 



In the early autumn of 1908 a case of witches'-broom of a bamboo, 

 PhyUostachys sp.,was submitted for inspection to the Bureau of Plant 

 Industry by Mr. Frank X. Meyer, one of the agricultural explorers 

 of the United States Department of Agriculture. Mr. Meyer col- 

 lected the material near Hankow, in central China, but he reported 

 that it has a wide geographical distribution and causes loss in many 

 sections. 



GENERAL APPEARANCE OF THE DISEASE. 



The general appearance of the disease is that of a witches'-broom 

 formation, although there is no fasciation of the host as results from 

 the attack of certain parasitic fungi, but the internodes are strik- 

 ingly abbreviated and the diseased branches plumelike. The effect 

 of the disease is more striking than the fungus itself, and is well 

 shown by a comparison of healthy and infected material in Plate I. 



HISTOLOGICAL CHANGES IN THE HOST. 



The time and point of infection are unknown, but from the histo- 

 logical changes in the host the infection probably begins in the young 

 tender tissue at the terminal node. In its mature stage the fungus 



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