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The Cultivation of 
 
 RUBBER 
 
 Dr. E.V.WILCOX 
 
 '<?^ 
 
 PUBLISHED BY 
 
 WILLIAM S. MYERS, D. Sc, F. c. S., Director, 
 
 Nitrate of Soda Propaganda. 
 
 Late of New Jereey State Agricultural College. 
 
 JOHN STREET AND 71 NASSAU, NEW YORK. 
 
Below will be found a list of pamphlets relating to 
 the use of Nitrate of Soda as a fertilizer, which will be 
 furnished gratis to persons desiring information upon 
 any of the subjects named. 
 
 The Cultivation of Cotton. 
 
 £1 Cultivo del Algodon. 
 
 The Cultivation of the Olive. 
 
 The Cultivation of the Sugar Cane. 
 
 El Cultivo de la Cana de Azucar. 
 
 Report on Alabama Cotton Prize. 
 
 Experiments with Chemical Fertilizers. 
 
 Abstract of Bulletin No. 52 on Onion Culture. 
 
 Extracto Del Boletin Num.° 52 sobre El Cultivo 
 de la CeboUa. 
 
 The Cultivation of Tobacco. 
 
 El Cultivo Del Tabaco. 
 
 Straight Fertilizer Formulas for Farm Crops. 
 
THE 
 
 CULTIVATION OF 
 RUBBER 
 
 Dr. E.V.WILCOX 
 
 PUBLISHED BY 
 
 WILLIAM S. MYERS, D. Sc, F. c. s., Director, 
 
 Nitrate of Soda Propaganda. 
 
 Late of New Jersey State Agricultural College. 
 
 JOHN STREET AND 71 NASSAU, NEW YORK. 
 
 P. 
 
Cornell University 
 Library 
 
 The original of tiiis book is in 
 tine Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924003326836 
 
The Cultivation of Rubber. 
 
 With the enormous increase which has taken place 
 in recent years in the use of rubber for old and new 
 purposes, interest has been awakened in the value and 
 importance of wild forest rubber and in the possibilities 
 of profitable rubber planting. The Custom House 
 records of New York City for December, 1909, show 
 an importation of 10,000,000 pounds of rubber. Dur- 
 ing the year 1909 the output of rubber from planta- 
 tions in British India amounted to nearly 380 tons per 
 month. The consumption of rubber in the United 
 States and Canada has constantly increased from 14,000 
 t(ns in 1896 to 31,000 tons in 1909. These ' figvires, 
 relating to the rapid increase in the use of rubber, 
 might be duplicated for other civilized countries and 
 show that the importance of this product is rapidly 
 increasing. Since the world was for a long time sup- 
 plied with rubber from wild trees, it was feared when 
 the commercial planting of rubber was undertaken that 
 the markets would soon be so flooded with rubber as to 
 greatly reduce the price. It was freely predicted that 
 the price of rubber might be driven down to twenty- 
 five cents per pound, and that when this event took 
 place all rubber plantations would be driven to financial 
 ruin, except such as were in the fortunate position of 
 being able to produce rubber at twenty-five cents per 
 pound. Contrary to these predictions, we have re- 
 cently seen very high prices for rubber and a demand 
 in excess of the available supply, in the face of large 
 outputs which are being marketed from plantations. 
 It seems safe to assume that with the increase in the 
 supply of plantation rubber the use of rubber wiU be 
 extended so as to take up the increase without lower- 
 ing the price beyond a profitable figure. 
 
 Kinds of Rubber Trees. 
 
 Much speculation has been indulged in regarding 
 the relative advantages of the different species of rubber 
 
of Rubber 
 
 Tiie trees. In Mexico attention has been given chiefly 
 Cultivation ^^ QastiUoa. In Ceylon and the Straits Settlements, 
 Ceara was tried, partly as a shade for other crops, and 
 partly as a source of rubber. It has been gradually 
 discarded, however, for Hevea rubber which gives 
 greater promise than any other species in the enormous 
 plantations of the British provinces of India. Like; 
 wise in Hawaii, where at first Ceara rubber was chiefly! 
 in favor, the trend of opinion was later toward Hevedt 
 and recent plantings have been chiefly of the lattefr 
 species. | 
 
 As is well known to the rubber world, the stand|- 
 ard of excellence in rubber has been set by Hevea in thte 
 Indian provinces. Nevertheless, profitable prices are 
 received for Castilloa and Ceara rubber and also for 
 various wild rubbers from the original forests. Recently 
 a quotation of $1.97 per pound was received for Ceai'a 
 rubber produced on the Hawaiian rubber plantations. 
 
 Cultivation Desirable. 
 
 Since rubber was first obtained from forest treek 
 growing under wild conditions, it was thought that 
 plantations might adopt similar methods and grow rub- 
 ber trees practically as a forest, without attention in 
 the way of cultivation. This idea, however, has been 
 pretty effectually dispelled. In numerous instances it 
 has been found that rubber trees respond as promptly 
 to cultivation and artificial care as other tree crops. 
 On some of the Hawaiian plantations there are culti- 
 vated Ceara trees one year old which are larger and of 
 more vigorous growth than three-year-old trees grown 
 under similar conditions, but without cultivation. 
 
 The time factor in securing a yield from rubber is of 
 the greatest importance. Even under the best condi- 
 tions, there is a long wait from planting until the age for 
 tapping, and financial success with rubber will be 
 greatly influenced by any methods which may be 
 adopted to hasten the maturity of the trees. 
 
 When the trees are 8 or 10 years old one can begin 
 to extract the Latex. At 30 years the trees are at their 
 maximum of production. 
 
The success obtained from the judicious use of "^^ 
 
 Nitrate of Soda with forestry and nursery stock, sug- 
 gests great success with Nitrate of Soda for hastening 
 the maturing of rubber trees. 
 
 Soil Requirements. 
 
 With regard to the soil and climatic conditions 
 favorable for rubber production, it is a difRciilt matter 
 to make specific statements. The requirements are not 
 so exacting that rubber trees will not thrive under 
 quite a variety of soil and rainfall conditions. We 
 often see the statement that Ceara rubber and the 
 related species, Manihot dichotoma and M. piauienm, 
 will grow in very dry regions. 
 
 While this statement is perfectly true, it is also 
 quite true that all of these species wUl grow more 
 rapidly, reach maturity more quickly and yield more 
 heavily where the rainfall conditions are more favor- 
 able. In very dry regions the period of rest, during 
 which the leaves are shed from Ceara rubber, is greatly 
 prolonged, and the date of maturit}' of the tree is 
 thus delayed. 
 
 Experiments thus far conducted, and observations 
 made on the natural habitat of the rubber trees, show 
 that these trees will thrive on a great variety of soUs. 
 Nevertheless, the best growth is obtained on soils which 
 are reasonably fertile and of which the physical proper- 
 ties are such as to prevent undue caking or stagnation 
 of the water supply. 
 
 In other words, rubber, like most other crops, will 
 thrive best on soUs which have a high power of retain- 
 ing moisture, and from which the moisture is given up 
 slowly. In such soils aeration is satisfactory, and the 
 application of fertilizers will have the most effect. 
 
 Fertilizers for Rubber Plantations. 
 
 With regard to the use of fertilizers on rubber 
 plantations, experimental information is very meagre. 
 In the large amount of literature on rubber cultivation 
 one meets everywhere with tentative suggestions 
 regarding the application of barn-yard manure, green 
 
 Cultivation 
 of Rubber 
 
Cultivation 
 ' of Rubber 
 
 '^•'^ manures and artificial fertilizers to rubber trees. These 
 suggestions, however, are, for the most part, not based 
 on actual experiments. 
 
 The best advice that can be given on the subject 
 at present is to have an analysis made of the soils and 
 then supply such elements as are actually deficient or 
 as are removed by the growth of the rubber trees. In 
 the cultivation of young plantations it may prove 
 profitable, and even desirable, to grow inter-crops 
 between the rows of rubber trees. This is easily possi- 
 ble if the trees are planted at intervals of twenty 
 feet. The crops to be grown between rubber trees 
 will depend somewhat upon the nature of the soil 
 and the amount of rainfall. If legumes are grown 
 as inter-crops the necessary humus and a portion of 
 the required Nitrogen will thus be supplied to the soil. 
 
 If other crops, such as cotton, corn or sweet pota- 
 toes, are planted between rubber trees, it must be 
 remembered that they, in turn, will take their share 
 from the soil fertility; and this point must be borne 
 in mind in considering the fertilizer problem of the 
 whole plantation. Until more extensive experiments 
 have been made, it is impossible to make more specific 
 recommendations as to a plan of fertilizing rubber 
 plantations to encourage the growth of. the trees. 
 
 Nitrate of Soda for Increasing Flow of Latex. 
 
 It has often been suggested that a scheme of fer- 
 tilization might be devised whereby the flow of latex 
 could be temporarily energized at each tapping period. 
 In order to gain evidence on this point, a series of 
 experiments were undertaken in Hawaii with Nitrate 
 of Soda. The fertilizer was applied, at the rate of 
 one-fourth and one-half pound per tree, a few days 
 before tapping. It was found best to incorporate the 
 fertilizer deeply and thoroughly in the soil over the 
 young and actively growing rootlets. If the soil, at 
 the time of application, be excessively dry immediate 
 effects may not be noticed from the application of 
 Nitrate of Soda until a rainfall occurs, or until artificial 
 irrigation is applied. If, on the contrary, the soil is 
 moist at the time of application, and gentle rains occur 
 
soon afterward, quite striking results are shown within J}^^^ 
 two or three days, but a deep and thorough incorpora- 
 tion of the Nitrate in the soil will be of advantage. In 
 some cases the yield of Ceara rubber trees was doubled 
 during the fall tapping period by the application of 
 one-half pound of Nitrate of Soda per tree. It has 
 not been determined exactly how the Nitrate of Soda 
 brings about this stimulation in the flow of latex, but 
 the fact appears to be true, and is believed to be well 
 worth considering at tapping time on commercial plan- 
 tations. The coagulation of the latex likewise appears 
 to be much improved from the use of the Nitrate of 
 Soda. 
 
 Experiments with Nitrate of Soda on Ceara Rubber were begun 
 by Prof. Jared G. Smith in 1905 and continued by the author, so 
 that Dr. Wilcox has had first hand experience based on personal 
 knowledge of conditions controlling the growth of India Rubber. No 
 doubt the growth of large, healthy trees is promoted most advanta- 
 geously by the rational use of fertilizer. 
 
 WILLIAM S. MYERS, 
 
 Director. 
 
 Cultivation 
 of Rubber