PORTO RICO AGRICULTURAL EXPERIMENT STATION 
MAYAGUEZ, P. R. 
Under the supervision of the 
UNITED 
STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 32 
Washington, 
D. C. 
June, 
1928 
EFFECT OF TOPPING ON YIELD OF COFFEE IN 
PORTO RICO 1 
By T. B. McClelland. Horticulturist 
CONTENTS 
Page 
Coffee branches 1 
Treatment 3 
Page 
Effect of topping and removal of 
suckers 4 
Conclusions 7 
The question of the advisability of topping coffee trees has recently 
received considerable attention from coffee growers in Porto Rico. 
The practice varies in different countries. In Colombia and Guade- 
loupe, for instance, heading back of coffee trees is universally prac- 
ticed, whereas in Porto Rico the trees are allowed to attain full height. 
COFFEE BRANCHES 
Dimorphism of branches must be taken into account in any system 
of priming coffee. The subject has been treated at length by Cook. 2 
A knowledge of the habit of growth of the coffee tree and of the 
differences between the kinds of branches is essential to a proper 
understanding of any pruning system practiced. 
The coffee seedling first produces a single upright stem. When the 
stem is approximately a foot high, further elongation is accompanied 
by the development of lateral branches. A pair arises from extra - 
axillary buds at the base of the topmost internode. and the three 
stems — the upright and the two laterals — elongate simultaneously. 
1 In this bulletin the term "coffee" refers to the common type of Coffea arabica only, 
some other species of the genus Coffea requiring wholly different treatment from that 
recommended for Arabian coffee. 
2 Cook, O. F. dimorphic branches in tropical crop plants: cotton, coffee, cacao. 
THE CENTRAL AMERICAN RUBBER TREE. AND THE BANANA. U. S. Dept. Agl\. Bill*. Plant 
Indus. Bui. 19S. 64 p., illus. 1011. 
T6231— 2S 1 
