December, 1912.] 



439 



COCONUT PLANTING IN THE WEST INDIES. 



BUD ROT. 



In contributing an interesting article to the West India Bulletin 

 on the subject of " Bud Rot of the Coconut Palm," Mr. J. B. Rorer, Mycol- 

 ogist to the Board of Agriculture, Trinidad, says that bud rot is un- 

 doubtedly the most serious disease of the coconut palm. It has been 

 known for many years, but recently has attracted much attention through- 

 out the West Indies on account of the losses resulting from its ravages 

 and the increased value of coconut properties. 



Cause of the Disease.— For many years, the cause of the disease was 

 a matter of mere speculation, with the result that it was ascribed by 

 many investigators to poor soil, lack of drainage and a great number of 

 different insects and fungi. Within the past few years, however, careful 

 studies have been made and the conclusions reached show that bacteria 

 are the real cause of the trouble and that insects are instrumental 

 only as carriers of infection. 



J. R. Johnston, late of the United States Department of Agriculture, 

 who has spent several years in the study of bud rot has proved by inocul- 

 ation experiments that the disease is due to a specific bacterium which is 

 so like Bacillus coli that the two cannot be distinguished ; in fact he 

 states that the disease can be produced by inoculation with pure culture 

 of B. coli 



Characteristics of the Disease.— The disease gains entrance to the 

 trees as a rule at the bases of the leaves or flower stalks. When the point 

 of first attack is in the outer leaves or older flower stalks, the bud and young 

 leaves may remain unaffected for a long time ; but if the infection takes 

 place in one of the central leaves, the bud soon rots and falls over often, 

 leaving some of the nut clusters and outer leaves still attached to the tree. 

 The course of the disease, once it has gained entrance to the tissues, may 

 be either slow or rapid, depending upon many conditions, but in all cases the 

 result is the same : namely, the whole top falls from the tree leaving 

 the naked stem standing. 



Whether or not the bacteria can gain entrance to the tissues through 

 the unbroken epidermis or whether a wound is necessary he has not 

 been able to make out. However, it is possible to infect trees without 

 wounding them artificially, simply by pouring a pure culture of the 

 causative organism into the crown. 



Bud rot must not be confused with the so-called root disease although 

 both may be present in the same tree. The latter trouble is always 

 characterized by discoloured roots and a distinct red ring of tissue in the 

 stem ; while in the case of bud rot pure and simple the roots and lower 

 stem seem perfectly healthy. 



Preventive Measures.— Bud rot has been quite prevalent in Trinidad, 

 but measures are being taken to prevent its spread. So far sanitation alone 

 has been used ; but the good results have been very marked in that the 

 disease has been greatly reduced. To prevent the spread of the disease, 

 trees which had been dead for a long time were simply felled, cut into 

 junks from 4 to 6 feet long, piled around the fctump together with as much 



