PORTO RICO EXPERIMENT STATION. 399 



coffee could not be grown without shade. The trees best suited for 

 the shading of coffee are recognized as the "Guaraa, Guava, Moca, 

 Hucare, and banana." The first two are considered superior to the 

 others, a fact which may be attributed to their being leguminous trees 

 and possibly furnishing nitrogen for use of the coffee trees. 



Coffee is grown chiefly in the interior of the island on the mountain 

 slopes and is confined largely to the west half of the island. The most 

 prominent municipal coffee districts are Utuado, Las Marias, Maricao, 

 Lares, Ciales, Adjuntas, Mayaguez, San Sebastian, Ponce, and Yauco, 

 in the order named. These ten districts produce 60 per cent of all 

 the coffee grown in the island. The Utuado district leads the list 

 with about 17,000 acres and is nearly the center of the coffee area. 



The soil conditions vary much from locality to locality, and even 

 on one plantation wide differences often occur. Coffee is very sus- 

 ceptible to soil changes, and many large estates are in part only 

 suited to the growing of coffee. This relation between soil and crop 

 does not seem to have been well understood by the native planter, for 

 many acres have been planted on lands that are poorly adapted to the 

 growing of coffee solely because of the character of the soil. The best 

 coffee is always found on soils of heavy texture, i. e. , soils that are 

 classed as clay loams or clay, and which continue heavy in texture to 

 a depth or 3 or more feet. If the depth of heavy soil is 2 feet or 

 less and is underlaid by stone, sand, or gravel the coffee becomes 

 poorer, as the underlying coarse material comes nearer the surface. 

 Sand or sandy loam never produces good coffee except it be nearly 

 level and well fertilized. While the red clays are considered the best 

 coffee lands, it is doubtful if the color has any bearing on their qual- 

 ity. The red indicates the presence of plenty of iron, which may be 

 an important factor, v but it is more likely to be the coincidence of the 

 red color usually accompanying the heavy clays. The coral limestone 

 along the north border of the mountains breaks down into a fertile 

 soil well suited to bananas, citrus fruits, and minor crops, and when 

 very fertile may produce good coffee, but such soils are not to be 

 compared with the heavy red soils further inland. The dark-colored 

 soils on the southern slope, especially those about Adjuntas and Yauco, 

 are also excellent for coffee. It is claimed by some that the black 

 soils produce greater yields than the red, but that the latter produces 

 coffee of the best quality and trees of the longest life. 



The coffee tree in Porto Rico is said to attain its maximum produc- 

 ing power at the age of about twelve years and continues in good 

 bearing condition to the age of fifty years. Trees are reported at the 

 age of eighty-two years only 2 to 3 inches in diameter, and in 

 good bearing condition. Wherever the soil conditions are not favor- 

 able to the coffee trees they are badly infested by a leaf miner and 

 affected by scale insects and fungus diseases. 



