HORTICULTUBE. 241 



during 1909 and 1911. Tlie region of cacao culture is briefly described and con- 

 sideration is given to tlie establishment of plantations, management, production, 

 financial returns, varieties, harvesting and preparation, statistics, diseases and 

 insect pests, transportation, and the relation of the State to the cacao industry. 

 . Citrus fertilization experiments in Porto Rico, C. F. Kin man {Porto Rico 

 Sta. Bui. 18 {1915), pp. 33, pis. 2, figs. 2). — ^This bulletin reports cooperative fer- 

 tilizer experiments in citrus groves which were started in 1905 by H. C. Hen- 

 ricksen, continued by M. J. lorus, and completed by the author. In order to 

 determine the comparative effects of nitrogen, phosphoric acid, and potash, 

 both comiDlete and incomplete mixtures of these elements secured from various 

 sources were applied. The results secured in three different groves are here 

 presented in tabular form and discussed. 



The results of the work as a whole show a pronounced effect on both trees 

 and quantity of fruit due to fertilization. This effect was greatest as to 

 trunk, top, and leaf growth, and as to leaf color where a complete fertilizer was 

 given. The difference in leaf color appeared to be most pronounced during 

 periods of drought. In one grove the color was poorest in the plat given no 

 phosphoric acid and in another grove the color was poorest where no nitrogen 

 was given. 



The growth in the check plats was so slow and unsatisfactory that all except 

 one were discontinued before the conclusion of the experiments. The appear- 

 ance and growth of the trees in plats given a complete fertilizer were practi- 

 cally the same, except that in a plat given nitrogen in the form of dried blood 

 they were not so thrifty. The weight of fruit harvested from check plats was 

 only 27 per cent of that harvested from complete fertilizer plats. 



In one grove the gain in yield by plats given three elements over those given 

 two was 80 per cent and in the other 44 per cent. Of the trees receiving only 

 two elements those given no potash bore more than those given no phosphoric 

 acid. 



The trees receiving no nitrogen gave the poorest yields. The average weight 

 of the fruit per hundred was heavier in the plats given no nitrogen than in 

 those where phosphoric acid or potash was omitted. The differences in yield 

 between plats receiving muriate of potash and sulphate of potash were too 

 slight to indicate the superiority of one form over the other. No differences 

 were noted between these plats in respect to quality, flavor, or color of the 

 fruit. In one grove where nitrogen was applied in the form of nitrate of soda 

 the yield was but 83.7 per cent of that where an equal amount of nitrogen was 

 given in the form of sulphate of ammonia. In another grove, however, there 

 was practically no difference resulting from the two treatments. On the basis 

 of the results of these experiments dried blood appears to be a somewhat less 

 favorable source of nitrogen for citrus fruits than either sulphate of ammonia 

 or nitrate of soda. No marked difference in flavor of fruit was observed result- 

 ing from the application of different fertilizers. There was also no apparent 

 difference in time of ripening of the fruit between the various fertilized plats. 

 The fruit ripened earlier in the check plat than in the fertilized plats. 



Drug plants under cultivation, W. W. Stockbergeb {U. S. Dept. Agr., 

 Farmers' Bui. 663 {1915), pp. 39, figs. S).— The author calls attention to a 

 number of drug plants suitable for cultivation in the United States and gives 

 general suggestions relative to the culture, harvesting, distillation, yielding, 

 marketing, and commercial prospects for drug plants. Specific information 

 secured from various sources in this department is then given relative to the 

 cultivation, handling, and yield of individual species, including also available 

 data relative to the demand and prices paid. 



