May, 1909.] 



in 



GUMS, RESINS, SAPS AND EXUDATIONS. 



THE NEW RUBBERS. 



[Paper read before the Board of Agri- 

 culture on April 7, 1909.] 



A good deal of information has 

 appeared during the past year in the 

 "Tropical Agriculturist" and elsewhere 

 concerning certain novel varieties of 

 Manihot, the genus to which Ceara 

 Rubber belongs. The reports so far 

 received as to the growth and yield of 

 these rubber trees in their native country 

 are so remarkably promising that little 

 or no apology seems required for an 

 attempt to put briefly before you a 

 summary of what is known at present 

 about these new and interesting 

 species. 



The first piece of information with 

 regard to these species to be received at 

 Peradeniya came in the form of a 

 circular from Messrs. Vilmorin, Andrieux 

 & Co., the great firm of seedsmen in 

 Paris, dated February 15, 1907. In this 

 circular a price was quoted for a large- 

 seeded species of Manihot— name un- 

 known—which was stated to be superior 

 in many respects to the Manihot glarAovii 

 or Ceara Rubber. An order tor 1,000 

 seeds of this species was at once des- 

 patched by Dr. Willis, but owing to the 

 failure ot Messrs. Vilmorin's supplies the 

 order was not executed until last year. 

 The seeds were received in August, 1908, 

 and 500 were sown on the Experiment 

 Station, Peradeniya, on the 12th of the 

 month. 280 of these seeds germinated 

 and developed into strong seedlings. 

 They were planted out 12 by 12 feet 

 apart in December, and, in spite of bad 

 weather for planting, they are all doing 

 remarkably well owing to special precau- 

 tions taken at the advice of Mr. Kelway 

 Bamber. 



At Kew, according to a recent bulletin, 

 the first account of the new rubber 

 plants was received in March, 1906, when 

 Mr. J. A. Davy, a Brazilian planter, 

 called at the Royal Gardens and left 

 seeds of the Jequie Manihot or Mani- 

 cobar, the plant to which the name 

 Manihot dichotoma has subsequently 

 been given. A large consignment of the 

 same seeds was sent to Kew in October, 

 1906, by Mr. J. P- Rowe of Bahia, and 

 from these plants were raised for distri- 

 bution and sent out from Kew in 

 Wardian cases on May 23, 1907. 



A case containing 100 of these plants 

 reached Ceylon in excellent condition. 



They were at first put out in a nursery 

 and were finally planted out on October 

 8, 1907, on level grouud 20 by 20 feet 

 apart. Some of these plants have made 

 excellent growth. The twelve largest 

 averaged 3 inches in girth, 3 feet from 

 the ground in May, 1908, and 6 to 7 inches 

 in November, 1908. Some months ago 

 these trees began to produce seeds, of 

 which a small number has been dis- 

 tributed. It is, of coarse, too early as 

 yet to begin any experiments in tapping 

 the trees, bnt the drop of latex obtained 

 on pricking the stem appears to be 

 decidedly rich in rubber. 



A further large supply of Manicobar 

 seeds was received from Kew in October, 

 1908. These included, iu addition to the 

 Jequie Manicobar, Manihot dichotoma, 

 already mentioned, a second kind, the 

 Remanso Manicobar or Maninot piau- 

 hyensis, which is said to be superior to 

 the former in many respects. 2,000 

 seeds of each species were sown at 

 Peradeniya ou November 2, 1908, whilst 

 others have been planted at Maha 

 Iluppalama, Henaratgoda, and else- 

 where. Out of 200 seeds of the Dichotoma 

 sown at Henaratgoda, practically all 

 germinated, so that there is every pro- 

 mise that the Department will soon be 

 in possession of a good supply of plants. 

 At Peradeniya the germination was not 

 so good, and only a very few plants of 

 the Remanso variety have appeared. 



The three species of Manicobar which 

 have beeu botanically described — 

 Manihot dichotoma, M. piauhyensis, and 

 a third M. heptaphylla, seed of which 

 we have not yet succeeded in obtaining 

 in Ceylon— occur wild in the Provinces 

 of Bahia and Piauhy in Brazil in latitudes 

 ranging from 8 to 15 degrees South. 

 So far much the fullest account of 

 these plants in their uative country is 

 that given by Dr. Ule in the "Tropenp- 

 flanzer"for December, 1907, a transla- 

 tion of which appeared in the "Tropical 

 Agriculturist " for March, 1908. From 

 this account it appears that these species 

 grow naturally in a much drier and more 

 mountainous country than the Para 

 Rubber {Hevea brasiliensis). 



"Here Manihot dichotoma grows in 

 the true Catinga forest, and is especially 

 abundant ou the mountain spurs. The 

 moie park-like regions where individual 

 trees stand scattered is avoided by 

 M. dichotoma, which prefers a rather 

 more thickly wooded country, It de- 



