CHAPTER IX. 

 YIELDS OF PARA RUBBER. 



Natural variations — Yields ^n Ceylon and Brazil — Henaratgoda trees 

 and Amazon yields — Yields on estates in Ceylon : Matale,Uva, Kalu- 

 tara, and Ambalangoda Districts — Illustration showing the rubber 

 trees on Passara Group Estate — § to 5 J lb. averages over large acre- 

 ages — Yields obtained in the Kalutara District for 1905 by the Kalu- 

 tara Rubber Co., RayigamTea Co., NebodaTea Co., Vogan Tea Co., 

 Southern Ceylon Tea and Rubber Co. , Putupaula Tea Estate Co. , 

 Yatiyantota Ceylon Tea Co., Eastern Produce and Estates Co., 

 Sunnygama Ceylon Estates Co., Yataderiya Tea Co., Kepitigalla 

 and Passara Group Estates, Ceylon Tea and Cocoanut Estate Co., 

 and Gikiyanakanda for 1905 — Yields on Imboolpittiya estate, 

 Nawalapitiya — Illustration showing rubber trees at Peradeniya 

 tapped on the full spiral system — Exceptional yields at Culloden, 

 Elpitiya, and Peradeniya — Comparison of yields at Peradeniya and 

 Henaratgoda — Experiments at Henaratgoda — Comparative yields 

 from different systems of tapping — Spiral and herring-bone tapping 

 compared — Results of high tapping at Henaratgoda from base to 

 50 feet — 16 tappings yield 3 £ lb. rubber — Average yielding capacity 

 per square foot of the bark tissues — Comparison of yields obtained at 

 Henaratgoda — Illustration showing the Elpitiya tree after 14 lb. 

 rubber extracted — Yields at Peradeniya by the V and spiral methods 

 — Rubber from shavings — Rubber yields in the Straits — Yield from 

 the Sandy croft Rubber Co., 1905 — Variation in yields in Java — 

 Yields in South India at high elevations — Hawthorn Estate and 

 Mergui Rubber Plantations — Para yields in the Gold Coast — Yields 

 of Para and African rubber compared — Difficulty in forming average 

 estimates — Eff oct of repetitional bark stripping — Illustration showing 

 the tapping of renewed bark — Excision and incision — Bark peeling. 



Natural Variations. 



WHEN dealing with the question of yields of dry rubber for a 

 known acreage or number of trees, it is necessary to indicate 

 the method of tapping adopted, the age of the trees, and the quality 

 of the resultant rubber. The age and size of trees greatly influence 

 the quantity and quality of the rubber, and it is to be regretted that 

 the yields over large acreages for several years in succession are not 

 at hand. Nevertheless, we do possess information of the yield of 

 particular trees during certain years and of large acreages of known 

 age for a limited period, and from these a fairly reliable statement 

 of probable yields can be arrived at. It should be clearly under- 



