348 ANNUAL REPOETS OF DEPARTMENT OF AGRICULTURE. 



at Castner is making fairly good progress, it having been found that 

 sorghums and pigeon peas grow rapidly in the manganese soils of 

 that region. 



The extension work of the station has been correlated with that of 

 the Territorial food administration to a considerable extent, the 

 superintendent of extension acting for a time as county agent for 

 Maui. The demonstration work inaugurated by him at Haiku has 

 given much valuable data for the use of the extension force. The 

 demonstration farms of the station are being widely observed, and the 

 agriculturists and the canning and packing interests of the islands 

 are beginning to place great dependence on the results secured on 

 these farms. 



POETO RICO STATION. 



The work of the station during the year consisted quite largely of 

 efforts to stimulate increased food production. The chemists con- 

 tinued their investigations on soil and fertilizer problems, a bulletin 

 on the Bat Guanos of Porto Rico and Their Fertilizing Value having 

 been issued during the year. Experiments have shown that sugar- 

 cane chlorosis is due to the fact that calcium carbonate depresses the 

 availability of iron below the amount needed by the cane. The 

 incorporation of organic matter, as stable manure, with the soil has 

 been found to correct the trouble to some extent. Particular atten- 

 tion has been given the phosphate requirements of soils, vegetation 

 experiments with a large number of type soils having been conducted 

 during the year. In the horticultural work especial efforts have 

 been made to improve native crops and to introduce new or better 

 varieties. This applies to sweet potatoes, yams, mangoes, citrus 

 fruits, coffee, cacao, vanilla, etc. The possibility of establishing vanilla 

 growing as an industry seems assured, and several cooperating 

 planters have been furnished sufficient cuttings to demonstrate the 

 commercial possibility of the industry. The experiments on coconut 

 fertilizers, intercropping, and cover crops have been continued with 

 some promising results. The plant-disease and plant-breeding ex- 

 periments were interrupted by the leaders entering military service 

 early in the year. In entomology the investigations on the changa 

 were completed and a bulletin issued on the subject. Work on the 

 life history of the May beetle has been begun. Interest in the eradica- 

 tion of cattle ticks has been aroused, and some cooperative work has 

 been begun. The station grounds have been freed from ticks, and 

 the insular government has become impressed with the importance and 

 benefits to be derived from the eradication of the tick. 



In addition to the investigations carried on, a large amount of 

 demonstration and extension work was done to arouse the people to 

 the importance of greater food production. Practically every mem- 

 ber of the station staff gave some or all of his time to this work. In 

 cooperation with the insular food commission, the entire island has 

 been districted and organized for increased production of food. 

 Many acres of idle land have been planted to food crops, and in some 

 localities sugar planters have allowed their laborers to plant beans 

 between the rows of young cane. So successful were the efforts 

 with this one crop that Porto Rico has become an exporter of beans 

 instead of a heavy importer. As a result of the food-production 



