340 EXPERIMENT STATION RECORD. [Vol. 36 



ciency. It is recommended that iu a normal season the spraying be done early 

 in July and again early in August. The cost of cutting was approximately three 

 times the cost of spraying. 



HOKTICULTUKE. 



Report of the horticulturist, 0. F. Kinman (Porto Rico Sta. Rpt. 1915, pp. 

 25-29, pi. 1). — Investigations with fruits, vegetables, and miscellaneous plants 

 were continued along lines previously noted (E. S. R., 33, p. 535). 



In the cooperative fertilizer experiments with bearing coconut trees marked 

 gains in yields were recorded for the complete fertilizer plats. Where 10 lbs. 

 per tree of a mixture containing 6 per cent nitrogen, 8 per cent phosphoric acid, 

 and 12 per cent potash was applied a gain of over 30 per cent in yield of nuts 

 per tree over the check plat was obtained. Where 20 lbs. of the mixture was 

 applied per tree the gain in yield of nuts per tree was 60 per cent. Where 

 nitrogen or potash was omitted, no increase in yield was recorded. With the 

 omission of phosphoric acid, there was only a slight increase. The average 

 diameter of the nuts from the different plats has varied but little since 1912, 

 when the experiments were started. Cooperative fertilizer experiments with 

 young coconut palms were commenced during the year. 



Thirteen varieties of the imported mangoes in the station orchard fruited 

 during the year and are here listed. Of these, Cambodiana has for several sea- 

 sons given the most promise for home planting, both from the standpoint of 

 yield and quality. The variety Alphonse, or Bennet, was promising for com- 

 mercial use during the past year, whereas the formerly promising variety Amini 

 gave poor results, both as to yield and size of fruit. Sandersha continued to be 

 the most prolific variety for use in making preserves or chutney. Observations 

 on the quality of fruit and seedling growth of different wild types found in 

 abundance have shown them to be inferior to the East Indian varieties, both as 

 to the edible and the keeping qualities of the fruits. The slower growth of the 

 wild seedlings makes them less satisfactory than seedlings of the introduced 

 types for use in grafting and inarching. Germination tests of common Porto 

 Rican mangoes show that the best results are secured when the husk is removed 

 entirely from the seed before planting. 



The tests to determine the influence of the Porto Rican conditions on northern 

 varieties of vegetables, here summarized, are noted below. 



The Smooth Cayenne pineapple, the commercial variety of Hawaii, has not 

 proved satisfactory for general culture in Porto Hico. The algaroba tree 

 (Prosopis juUflora) introduced from Hawaii has succeeded well in the southern 

 part of Porto Rico, where the rainfall is light and the soil is sandy. 



The bean Canavalia incurra, cultivated as a vegetable in a number of Asiatic 

 countries, made poor growth and yield as compared with the jack bean (C. 

 ensiforniis), and the brown and purple seeded types of C. gladiata commonly 

 grown in Porto Rico. The bean Botor tetragonoloha from the Philippine Islands 

 has been very thrifty and prolific, although not so rich in quality as many com- 

 mon garden varieties of beans. The vines have large leaves and showy blossoms 

 and are adapted for protecting verandas. A cowpea introduced from India 

 appears to be well suited to conditions in Porto Rico and more valuable as a 

 soiling or cover crop than the types commonly grown. 



Experiments on the supposed deterioration of varieties of vegetables in 

 Porto Rico, with suggestions for seed preservation, C. P. Kinman and T. B. 

 McClelt.and {Porlo Rico Sta. Bui. 20 (1916), pp. 5-30, figs, ii).— This paper 

 gives the results in detail of several years' study on the question of the supposed 

 deterioration of varieties of vegetables when grown through several generations 

 in the Ti-opics. 



