228 



THE AGRICULTURAL NEWS. 



July IS, 1!)11. 



FRUIT AND FRUIT TREES. 



NEED FOR THE CLASSIFICATION 

 OF MANGOES. 



It ha.s frequently been poiuteil cnU in this journal that the 

 application of science to tropical fruit has been largely neg- 

 lected compared with the systematic attention given to fruit 

 grown in temperate countries. This has been due largely t(.i 

 the unimportance, until receiit years, of tropical fruits in the 

 world's commerce, and to the extensive areas over which the 

 different varieties and species of any particular fruit are 

 scattered. In the case of the banana, pine-apple and coco-iuit, 

 which have of late years formed tlie basis of enormous 

 industries, a considerable amount of attention has been given 

 to the classification of the best varieties, but even as regards 

 these fruits, a great deal remains to be done before the 

 large number of different forms are convenie7itly systematized. 

 In the case of the mango much less work has lieen carried out 

 in this direction, and therefore, particularly welcome on this 

 account is the paper recently published by Mr. F. W. Popenoe 

 describing a Ijasis for the future classification of the mango. 

 It is suggested that greater care should be given to the 

 description of the fruits of different varieties. The mango 

 fruit possesses certain characteristic features which are different 

 and constant for the several varieties. Of these features, the 

 cavity at the base of the stalk, the dorsal shoulder and the 

 ventral shoulder each side of the stem are important character- 

 istics, whilst equally worthy of observation are the ventral 

 edge of the seed and the apex and what is known as the beak 

 of the fruit — the point on the ventral side at the base of 

 a mango. After giving an outline of the basis on which the 

 fruit should be fully described, the author puts forward the 

 ff)llo^ving suggestions as regards the classification of the 

 mango in general: — 



'An accurate and systematic classification fif varieties is 

 at present one of the greatest desiderata in connexion with 

 mango culture. There seems to he ample basis for a classifi- 

 cation by natural characteristics, in which, could all named 

 varieties be included, their relationships would be vividly 

 brought out, and the synonomy established of many consid- 

 ered distinct. 



'The principal obstacle confronting such a work is the 

 widespread distribution of the mango, making it impossible 

 to gather together all varieties' for study and comparison. 

 There is no reason, however, why a dassificatory .system could 

 not be formed which could be applied by each pomologist to 

 the varieties of his particular region, when a collaboration of 

 the various investigators would bring together the fragments 

 and produce the desired result. At ])resent our knowledge 

 of the mango is so elementary that no satisfactory system 

 of classification can he drawn up, the subject requiring much 

 more study and investigation than have so far lieen given it. 

 'Recent investigations seem to indicate that all mangoes 

 can be divided into two classes, nionoemliryonic and polyem- 

 bryonic, which in a classification might form the first great 

 division. The Indian mangoes as a rule appear to be 

 monoembryonic, while those in the Philippine Islands as well 

 as some now grown in Florida, ilexico and the West Indies, 

 are polyembryonic. The polyembryonic varieties have the 

 characteristic of reproducing themselves fairly true to type 

 ■when grown from seed, by some authorities believed to be 

 due to the fact that the emliryos are adventitious and not 

 formed from the germ cells in the ovary, i.e., they are not 

 the product of the fertilization of tlie ovule, as is the single 

 plant produced from the seed of the monoembryonic type, 

 whose progeny is variable. 



'Following the division into two primary classes might 

 come the subdivision of each into distinct races or types. 

 Indian horticulturists already recognize a number of more or 

 less distinct types, .such as the Langras and ilaldas, each of 

 which include a numljer of closel}' related \arieties, having 

 in common certain characteristics which prove their altinity. 

 Maries divided the mangoes of his acquaintance into four 

 classes — Bond)ays, Maldas, Langras and Budayas; Rolf.s 

 divided the mangoes of Florida into seven groups, while 

 Wester has found three distinct types in the Philippines. 

 Many so-called \'arieties are in reality races or types enilirac- 

 int; a nundier of verv closelv allied forms.' 



SUGAR INDUSTRY. 



RESULTS OF THE ST. CROIX SUGAR- 

 CANE EXPERIMENTS. 



Tables setting forth the results of the experiments with 

 new varieties of sugar-cane at the Agricultural Experimenl> 

 Station, St. Croix, D.W.I., are pulilished in the St. Croix 

 Ai<is for May 30, 1914. Again it is a matter of interest to 

 observe how little reliance can be placed upon the results 

 which a new variety of cane gives in its first and second years 

 of growth. The only 191 2 seedlings which came within the 

 first ten in that year and have retained their po.sition in 1913 

 and 1914 are Nos. 12-1, 12-2, 12-4, and 12-fi. Cane 12-11 

 has done well in both 1913 and 1914; it has headed the list 

 in 1912 and also headed the list of 1912 seedlings planted in 

 May 1913. Canes' 12-34 and 12-48 are interesting on 

 account of the very high yield which they have given this 

 year, the former having produced cane at the rate of 60 tons 

 per acre and the latter at the rate of over fiO tons per acre. 

 Last year these two canes took cpiite a low position. 



An interesting observation was that which showed, in 

 the course of the experiments, that duplicate plots of the 

 .same variety gave the same yield of cane though the number 

 of stools in the duplicate plots differed considerably. Another 

 point of interest is the fact that there is a wide variation in 

 the amount of juice expres.sed from the different varieties 

 of cane by the laboratory mill and the wide variation in 

 the richness and purity of the juice (jf different varieties. 

 This is well exhibited by the results obtained with SC 12-41 

 which, while taking the tenth place in point of tonnage, takes 

 the first place in point of sugar yield yer acre. 



For fuller information on the subject of these interesting 

 experiments the reader is referred to the Official Report of 

 Dr. Longfield Smith, Director of the St. Croix Department 

 of Agriculture. 



Growth in the Application of Polarimetry.— 



In recent years there has lieen a rajiitl extension in the 

 employment of the polariscope for commercial |jurposes and 

 the Louisiana Planter (June 6, 1914) states that the United 

 States Department of Commerce has found it necessary to 

 revi.se Circular No. 12 dealing with the basic principles of 

 modern polarimetry. The preceding circular has been enlarged 

 by a resume of the work done at the Piureau of Standards 

 and elsewhere. The publication deals further with the various 

 scales, French, German and international, with light sources, 

 various minor apparatus, the testing of raw sugars, the mixing 

 of samples, the determination of moisture, the use of the 



