190 



THE AGRICULTURAL NEWS. 



June 5, 1915. 



HAWAII: ANNUAL REPORTS ON THE AGRI- 

 CULTURAL AND EXPERIMENT STATIONS FOR 

 1918 AND 19U. 



These two publications, which have been received 

 simultaneously, contain much useful information of interest 



to the West Indies. It will l>e convenient in reviewing 

 them to confine attention to the summaries of investigations 

 written by the special Agent-in-charge of the Station 



(Mr. K. V. Wilcox). 



In the 1913 report, the chief matters of interest j ie 



nuclei' the headings <>f horticultural and chemical investiga 

 tions, respectively. The studies that have been made on the 

 papaw were continued, and one of the most interesting 

 results of this work is the apparent certainty that within 

 one or two more generations of papaw breeding, the dioecious 

 condition in which this tree ordinarily occurs will be 

 eliminated, with great practical advantage to the papaw 

 grower. A strain has alread) been originated in which over 

 !•'_' per cent, of the trees are self-fertile fruit-bearing trees. 

 This has been accomplished by close fertilization of her- 

 maphroditic flowers, with the result that the occurrence of 

 male trees has already been largely eliminated, and the 

 variation due to cross-fertilization thus avoided. It has 

 been found also to be a very easy matter to graft papaws. 

 A union takes place even between the pith of the scion and 

 the stock. 



In further work with pine-apples it has been found that 

 the shape of the fruit is subject to hereditary transmission as 

 well as other characters. Suckers from plants which bear 

 cylindrical fruits arc far more likely to produce cylindrical 

 fruits than are plants which bear conical fruits. Since the 

 cylindrical fruit is of considerable importance in canning, 

 for the reason that a large number of slices of uniform size 

 can be obtained, it is desirable to select suckers with refer- 

 ence to the shape of fruits which they will produce. 



Turning to the section dealing with chemical investiga- 

 tions, it is learnt that analyses have been made of various 

 Samples of larva taken from historical Hows of known date. 

 It has therefore been possible to study the formation of 

 Hawaiian soils from the standpoint of their history, and to 



[earn the changes which have taken place in the disintegration 

 of larva into agricultural soil. It is stated in the report that 



tin opportunity for such is one rarely presented except in 

 Hawaii; it might be suggested, however, that similar work 

 might be done, providing equipment were available, in West 



1 1 k 1 1 > ] , islands like Martinique and St. Vincent where larva 

 flows of known date occur. In the study of the nitrogen 

 content of Hawaiian soils it has been found that fallow or 

 virgin soils contain no nitrate, or merely a trace, while the 

 .■.in- unt of ammonia ma\ be rather large. Upon thorough 

 cultivation, however, nitrification takes place quite rapidly, 

 with the result that the form of soil nitrogen is quite 

 different in cultivated end uncultivated soils. 



Some experiments have been made- in an attempt to 

 develop met hod- of economically utilizing the large quantities 

 of pine-apple juice wasted in the canning process While 



pine-apple juice may perhaps be most economically used by 

 condensing into a syrup to replace a part of the sugar in 

 canning, it may also be Used in the production of a good 

 quality of vinegar. By the epiick process, a vinegar con- 

 taining from •">.'. to 4.'. percent, of acetic acid may be produced 

 in twenty four hours, and the percentage of acid will increase 

 by subsequent -landing. No difficulty i- experienced in 

 securing the acetic fermentation after the proper alcoholic 

 fermentation has been brought about, but the main difficulty 

 is encountered in handling the juice so as to prevent an 

 improper fermentation at the start, thus destroying the 

 flavour "f the vinegar or preventing the formation of 

 sufficient alcohol. 



The report tor the year L91 I begins with a reference to 

 the trouble which has been caused in the fields of Hawaii 

 by the sedge commonly known as tin- Japanese nut grass 

 (Ci/pervs rotund us). This pernicious weed has spread rapidly 

 and no really efficient method has been evolved whereby it 

 can be eradicated or even kept down. With reference to the 

 papaw experiments mentioned in the previous year's report 

 it is stated that the results obtained in 1914 give 

 promise of complete success within two or three more 

 generations of papaws. The examination of fo 1 trees of the 

 second generation of breeding showed that 95J percent, of 

 these trees are fruit-bearing with perfect flowers. Two male 

 trees were cut off •'! feet from the ground, and when the new 

 branches came out it was found that the sex had been 

 changed and that regular perfect Mowers each bearing fruit 

 were developed. Further work on the papaw has been that 

 dealing with the production of papain. It has been found 

 that dried papain can be produced at a profit for about $2*50 

 per lb. Interesting experiments at the station have shown 

 that if in the early morning a dozen shallow lengthwise 

 incisions .',- to |-inch apart are made in a papaw tree of good 

 size, enough juice will be obtained to make .',-oz. of dried 

 papain. Fruits may be tapped on alternate days five to 

 seven times in all. As soon as the fruit begins to turn 

 yellow the milky juice flows [ess freely. The tapping wounds 

 heal quickly, and the fruit is not injured by tapping; in fact, 

 the flavour appears to be somewhat improved, since a slight 

 bitterness which cliaracteriz.es the juice is thereby removed. 

 Chemical investigations have concerned principally the 

 effect- of heat upon the soil. One of the striking effects was 

 tin- unusually rapid formation of ammonia after the soil had 

 been heated Heating soil- seem- to bring about rapidly the 

 effects which are otherwise obtained more slowly by 

 aeration. I» has been noted in the case of all plants that 

 growth is much more rapid on heated than on indicated 

 soils. Attention has been devoted also to a study of the 

 physical propertiesof soils with interesting results, which may 



be Summed upbj saying that in heavy clay soils all fertilizers 



used alone, or in mixture al the ordinary rate, have been found 

 to check the movement of soil moisture. In a study of the 

 function of fertilizers in soils it was found that phosphoric 

 acid was fixed to a greater extent than other fertilizers. The 

 use of dynamite for soil improvement continues t" increase-. 

 Satisfactory results have been obtained on pine-apple 

 plantations, but it is emphasized that in all cases where 

 dynamite is employed, the soil must be dry. The use of 

 dynamite for the improvement "f lawns has been found 

 particular!} satisfactory. 



In concluding we may make reference briefly to one or 

 two miscellaneous matters. Much attention has been given 

 to the cultivation of legumes, particularly beans, for instance 

 the Algaroba bean (Protopis juniflora), which provides a valu- 

 able meal for horse- and mules. interesting work has been 

 conducted in regard to the cold storage of tropical fruits. It 



