INSULAR EXPERIMENT STATIONS. 27 



The experiments with the old and new phintings of coffee have been 

 continued, and in the old plantation the cost of production last year 

 was $5.18 per 100 pounds of coHee, which was sold for $11.98. In 

 the new plantation the cost for the five years since this experiment 

 was begun has been $101.50 per acre. A small crop was gathered 

 last year, the net value of which was $8.85, making the net cost of 

 planting, culture, and other factors, for the first five years, $92.71 

 per acre. 



The plant jiathologist is continuing his investigations along the 

 lines described in the previous report. The diseases of citrus fruits 

 have received but little attention, no new problems having appeared. 

 A disease of mangoes similar to the wither tip is receiving attention. 

 Spraying with Bordeaux mixture was found to give good results 

 at the station, the sprayed trees bearing heavily while the unsprayed 

 ones yielded little or no fruit. Some studies on the diseases of pine- 

 apples and cacao are in progress and various treatments are being 

 tested. The coffee trees have been found subject to a number of 

 fungus diseases. The leaf blight {Pellicularia koleroga) was quite 

 destructive during the wet season. A second leaf blight {Stilbum 

 flaoidum) is of comparatively little importance, as the conditions for 

 its best development are present only at elevations of 2,000 feet or 

 more and relativeh' little coffee is produced in Porto Eico at this 

 elevation. A new disease of coffee in which the tree trunks are 

 girdled at or near the ground is being investigated. Some attention 

 is being given to the diseases of sugar cane and their control, and 

 the methods recommended as effective in other countries are being 

 tested. Some progress is reported on studies of the fungus parasites 

 of aphids and scale insects. 



The station has added to the equipment of live stock and has a 

 number of head of horses, cattle, hogs, sheep, and poultry, all of 

 which are being used in breeding experiments. These experiments 

 have been in progress long enough to warrant some possible con- 

 clusions. With cattle the prepotency of Shorthorn and Hereford 

 sires is very apparent. Four young crossbred Indian bulls of the 

 race Hissar were obtained during the past year. They were secured 

 to renew the vigor of an introduction made some sixty years ago, the 

 presence of which blood is still a])parent in the size and conforma- 

 tion of many of the work animals. The Berkshire breed of hogs 

 has proved well adapted to Porto Rico, and 21 head were sold at a 

 nominal price for breeding purposes. The experiments with African 

 woolless sheep have proved successful, the flock being increased 

 during the year from to 20 head. Great interest is taken in the 

 poultry work, and during the year the station sold 14 cockerels and 

 pullets and 142 settings of eggs. The nonsitting breeds seem most 

 suited to Porto Rican conditions, although the intermediate ones, 



