36 



HISTORY AND CAUSE OF THE COCONUT BUD-ROT. 



coast has by far the most coconut trees of any part of the island. 

 From Aguadilla along the north shore to San Juan these palms appear 

 at intervals in small groves, but never in large numbers. Trees of 

 these groves as far as examined had no sign of bud-rot, nor any serious 

 infectious disease. 



The examination of the coconut industry in Porto Kico concluded 

 the preliminar}^ survey of the writer in regard to the distribution 

 of bud-rot. Visits have also been made to the few gi'oves on New 

 Providence Island in the Bahamas, and to small groves scattered 

 along the coast of Colombia and Venezuela; but in none of these 

 districts was the coconut industry of any great importance, nor was 

 any very serious disease found among them. The writer has not 

 visited southern Florida, but understands from Prof. P. H. Rolfs 

 and Dr. E. A. Bessey that none of the groves in that region have as 

 yet shown any signs of this disease. 



a6i;aoii.la 



67° 



scat/ 



66« 



— ; 



po/?ro /?/co 



5 10 15 20/f//es 



A T L A N T / C 



SAN JUAN 



CS/^MJU^M 



MAVAGUEZ. 



.A' 



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Fig. 7.— Map of Porto Rico. The location of coconut groves is indicated by dots. 



STRUCTURE OF THE COCONUT TREE. 



In order to understand the nature of the experimental work on the 

 cause and methods of control of bud-rot it is necessary to know thor- 

 oughly the structure and arrangement of the parts of the coconut tree. 

 The tree consists of a single unbranchcd trunk crowned by a huge 

 rosette of leaves. Each of these leaves at maturity may be anywhere 

 from 4 to 7 meters in length and from 1 to 1.5 meters in width. The 

 leaf consists of a single heavy racliis bearing the simple pinnae. This 

 rachis, or leafstalk, broadens out at tlie base so as to form a complete 

 sheath about the trunk. (See fig. 8, petiole a broadening out into a 

 leaf sheath.) From its thin, fibrous character the sheath is commonly 

 caUed the strainer. Tliis forms a tough, tight binding about the 

 inclosed portions. An average mature tree has from 25 to 30 

 leaves. The distance from the lower leaves of the under part of 

 the crown to the center of the crown, the base of the highest 



228 



