NUT CROPS 273 



use in the fresh state they are largely used for oil 

 making. Some well-marked varieties occur and 

 individual trees are known to vary greatly in pro- 

 ductiveness and in the size and quality of the nuts, 

 but as is the case with so many tropical products 

 almost no attention has been given to selecting these 

 better strains for propagation. 



Cocoanut bud rot is one of the most destructive 

 of known plant diseases. The foliage on a thrifty 

 bearing tree suddenly turns a little yellowish and 

 the petioles of the great leaves will droop a little 

 and stand at a slightly wider angle, and the imma- 

 ture nuts will begin to fall. It takes a keen e3^e to 

 catch this first symptom of trouble in the leaves and 

 to differentiate it from the yellowing caused by scale 

 insects or other troubles, but the falling of the 

 young fruit is an almost certain symptom of in- 

 cipient bud rot. As the disease progresses the 

 yellowing and general demoralization of the foliage 

 becomes more pronounced, until finally the entire 

 top of the tree suddenly blackens and falls away, 

 leaving the trunk standing as a leafless stump. 

 Sometimes the oldest leaves will not be affected, but 

 will remain green for a time after the bud and 

 upper younger leaves have rotted and fallen. The 

 disease seems unquestionably to be a bacterial one, 

 although this has not as yet been absolutely proven 

 by successful inoculations with pure cultures of the 

 germ. Dissections of the diseased trees at any 

 stage will show more or less extensive areas where 

 the young tissues are being attacked by a soft 

 watery rot. When this finally reaches the large 



