748 EXPERIMENT STATION RECORD. [Vol.38 



nursery and other mango trees may be transplanted successfully if they are not 

 making a new growth and rainfall is plentiful. 



The confusion in the classification of types of mangoes as well as the great 

 variation in growth and productiveness of the trees and quality of fruit seri- 

 ously handicap the present development of mango orchards in Porto Rico. Of 

 the imported varieties that have fruited, the most productive of the thrifty 

 kinds with fruits of high quality are Cambodiana, Totafari, Amini, Bennett, 

 and Paheri. Of these, Cambodiana and Paheri appear to be better suited to 

 home than to commercial use. Fruits of the native varieties and all varieties 

 from Martinique. Trinidad, and South America are less desirable than many of 

 the other imported kinds. 



The station's work has shown that mangoes that have not softened on the 

 tree should be picked with a stem longer than the fruit stalk so as to prevent 

 the juice of the base of the fruit from escaping through the fruit stalk and 

 leaving passages for the entrance of infection- Fruits in orange wrapping paper 

 did not ripen or decay so quickly as those wrapped in oil paper, newspaper, or 

 coconut fiber, or those left in the open air. Fruits packed in coconut fiber 

 ripened earliest. East Indian varieties showed much better keeping qualities 

 than the native varieties. 



The author points out that the mango is one of the most satisfactory orna- 

 mental trees for Porto Rico and that it is possible to select from varieties pro- 

 ducing fruit of high quality those which best carry out a particular scheme of 

 landscape gardening. 



Report of the horticulturist, C. F. Kinman (Porto Rico Sta. Rpt. 1916, pp. 

 11-21, pis. 2). — A progress report on investigations with pineapples, coconuts, 

 and mangoes, including notes on some miscellaneous introductions. The work 

 with mangoes is reported on in a bulletin on page 747. 



During the past two years the work with pineapples has included a compari- 

 son of the effects of nitrate of soda and sulphate of ammonia in a complete 

 fertilizer. The results of these tests indicate not only that sulphate of am- 

 monia is the most desirable source of nitrogen for pineapples in soils similar 

 to that at the station, but that nitrate of soda should not be used for fertilizing 

 pineapples in this soil type and that experiments should be conducted to deter- 

 mine Its value in other soil types before it is used commercially. The plants 

 receiving their nitrogen from sulphate of ammonia continued their vigorous 

 growth and maintained their healthy color throughout the year, whereas those 

 on the other plats, including the plats receiving nitrogpn from nitrate of soda, 

 made a very slow growth and remained abnormal in color. 



In the fertilizer experiments with coconuts the plats receiving a complete 

 fertilizer continue to produce much larger crops than those given an incomplete 

 mixture, whereas in the group of plats where either nitrogen, phosphate, or 

 potash is omitted from the fertilizer the yield is little heavier than that of the 

 check plat. Complete fertilization has gradually increased the number of nuts 

 harvested, but the average diameter of the nuts has remained practically the 

 same throughout all plats in the experiment. Measurements made of the husks 

 and nuts from a number of selected trees for several years have shown that the 

 product from a given tree varies little in size and proportion of husk and nut 

 from harvest to harvest. A study is being made of the progeny of seed from 

 selected trees. 



Twenty varieties of American-grown sweet potatoes, which were sent to the 

 station by the Bureau of Plant Industry of the U. S. Department of Agriculture 

 in 1911 and grown at the station, have all lost their characteristic flavor and at 

 least some of them have developed a coarseness not common on the mainland. 

 These importations are not in general superior in flavor or texture to the types 



