588 ANNUAL REPORTS OF DEPARTMENT OF AGRICUL.TURE. 



The chemical department has devoted much time to study of 

 the utilization of surplus fruits, vegetables, etc., and has been in- 

 strumental in developing a starch industry as well as industries for 

 the preservation of various fruits. Preliminary experiments have 

 shown that there is probably no basis for the rather common belief 

 that locally grown vegetables are deficient in iron and other mineral 

 substances, and that, therefore, imported vegetables have a higher 

 nutritive value. 



The extension activities organized in 1914 have been extended to 

 cover all the larger islands, and helpful contacts have been estab- 

 lished with various agricultural interests. An agent on the island 

 of Hawaii has charge of the Glenwood demonstration farm and 

 he visited all important localities and assisted in the solution of 

 some of their more pressing difficulties. At the Haleakala demon- 

 stration farm on Maui work is in progress to show what crops are 

 adapted to that homestead area, and some assistance has been given 

 to school clubs and home gardeners. Preliminary work with boys' 

 and girls' clubs gave such promising results that a full-time leader 

 to develop this work was appointed in April and a number of clubs 

 have been organized. A part-time collaborator carried on demon- 

 strations of the use of locally grown food products, especially of 

 some of those less widely known, and an average of more "than 

 500 contacts with parents of various nationalities were established 

 monthly. The campaign also included efforts to encourage the 

 wider use of milk and milk products which are not sufficiently used 

 in the diet of many of the people. 



PORTO EICO STATION, 



The Porto Rico station is endeavoring to withdraw from the ex- 

 tension field in favor of local agencies and is devoting its energies 

 more and more to the solution of various problems connected with 

 the diversified agriculture of the island. The insular bureau of 

 agriculture is expanding and as rapidly as it is prepared to do so 

 is taldng over the extension work, the station being called upon to 

 act as technical adviser and instructor of the various local agents. 



Ever since the establishment of the station attention has been 

 given to problems connected with the management of soils under 

 tropical conditions. The former chemist has completed a series of 

 reports on the reaction of soils to various amendments, and in his 

 last contribution gave an account of the efficiency of phosphatio 

 fertilizers in Porto Rican soils as influenced by liming and by the 

 length of time they remain in the soil. The character of the soil 

 was found to materially influence the availability of added phos- 

 phates and the effect of the different phosphates varied widely 

 under the conditions of the experiments. The relation of the lime 

 requirement of soils to the efficiency of phosphates was determined 

 for a number of typical soils. In another investigation reported 

 by the chemical department of the station, certain nitrogenous fer- 

 tilizers were found to favor the development of chlorosis in rice, 

 either through their action on the plant or by rendering the iron in 

 the soil unavailable. Nitrates in general were found less suitable 

 for the fertilization of young rice plants than were the ammonium 

 salts used. 



