606 EXPERIMENT STATION RECORD. [Vol. 38 



methods for water culture experiments worked out by the chemist 

 have been described in scientific journals. 



One of the early lines of endeavor of the station was in the im- 

 provement of live stock through the introduction of pure-bred sires. 

 This work has proved very popular and the results are beginning to 

 be apparent in many parts of the island. Experiments begun on 

 the sanitary production of milk are reported to have brought about 

 great improvement in the quality of the milk supplies. 



Attention has been given to the introduction of new crops and 

 improved varieties of old ones with the result that many introduced 

 varieties have to a large degree supplanted those previously grown. 

 The value of introduced forage crops and the use of cover crops, 

 not only for the prevention of erosion but for the improvement of 

 the soil, and the superiority of improved varieties of fruits, etc., have 

 been fully demonstrated. 



In horticulture, citrus and coffee culture have received much atten- 

 tion. Fertilizer and cover crop experiments with citrus trees have 

 indicated improved practices that have been widely applied. With 

 coffee the experiments have had to do with soils, fertilizers, pruning, 

 varieties, seed-bed and nursery treatment, diseases, and insect pests. 

 Improved varieties of coffee have been introduced from other coun- 

 tries and some of them have proved especially adapted to Porto 

 Rican conditions. Vanilla growing, an industry new to the island, 

 has been developed, and it is possible that this will in time become 

 of considerable economic importance. As very little cacao has been 

 produced in Porto Rico, experiments are in progress that are ex- 

 pected to show the possibilities of developing cacao production on a 

 larger scale. Experiments with coconuts have been in progress for a 

 number of years, and data obtained regarding coconut culture will 

 soon be available for publication. 



As plant diseases and insect pests take heavy toll of agricultural 

 and horticultural products in tropical countries, the Porto Eico Sta- 

 tion has given special attention to a number of problems in connec- 

 tion with life history studies and means of control of some of the 

 more important plant enemies. Beekeeping, an industry owing its 

 origin to the station, has been developed within the past ten years, 

 and now exports of apiary products valued at more than $330,000 are 

 reported for the nine months ended March 31, 1918. Demonstra- 

 tion and extension work have been developed to a small degree, espe- 

 cially of late, in order to secure larger local production of food 

 crops. As a result of a campaign conducted by the station, Porto 

 Eico during the past year, instead of importing beans valued at 

 $800,000 annually as in former years, supplied its own necessities and 

 had a surplus of this product for export. 



