April 1910.J 



297 



Saps and Exudations, 



ably less than can be done from the 

 Straits or Ceylon ; however, even taking 

 the cost of cultivation, tapping, etc., at 

 one shilling and rubber at four shillings 

 per lb. Example II. points to a nett 

 profit of over £50 an acre at five years 

 old. (£100 with rubber at its present 

 price.) I hope some of your readers in 

 Coorg, where I believe Ceara has been 

 extensively planted of late, will forward 

 some of their results ; in any case I am 

 perfectly satisfied in my own mind that 

 Ceara, if taken up seriously, can and 

 will do for Mysore what Para has done 

 for the Straits Settlements. 



CLEAN WEEDING V. TEPHROSIA. 



CAOUTCHOUC AND ITS COLLEC- 

 TION IN THE UPPER AMAZON 

 REGION. 



(By O. Sperber, Tropenpfl., Febru- 

 ary, 1910. Abstracted by J. C. WlLLIS.) 



These districts, which belong to Peru, 

 turn out to be richer in rubber than was 

 anticipated. 



At present the collectors only tap the 

 following species :— 



Feet high. Diameter. 



Hevea guayanensis, ... 50-65 ... 2'6"-3'6" 



„ brasiliensis ... 55-65 ... 2'6''-3'6^ 



andimensis ... 5C-65 ... 3'0"-3'6" 



,; lutea ... 55-65 ... 2' -26" 



Castilloa elastica ... 50-65 ... 2' -2'6" 



There are, however, several other 

 Euphorbiacese that will yield rubber, 

 and which will doubtless be tapped 

 sooner or later. 



As the worker has to travel even for 

 months by boat, the stretches between 

 the rivers have as yet been but little 

 exploited. 



The workers seek new districts in July, 

 August and September, when the rub- 

 ber trees bear the differently coloured 

 young leaves. 



Tapping begins in October and lasts 

 till December. During the next three 

 months the rain makes the trees un- 

 approachable, and they are again tapped 

 in April, May and June. The average 

 yield of a tree is 5 kg. (11 lbs.) of first- 

 class rubber. 



Official statistics of export give 



1904 

 1905 

 1906 



lb. value 



4,814,055 

 5,484,371 

 5,531,171 

 6,661,435 



Mk. 



13,250,264 

 18,370,465 

 14,668,350 

 19,091,459 



(Prom the Agricultural Bulletin, Straits 

 and P.M.S., Vol. VIII., No. 4, April, 

 1908, p. 131.) 



For a long time scientists have called 

 attention to the disadvantage of weed- 

 ing and have advised the introduction 

 of new methods ; but their ideas have 

 not been well received, and so far little 

 has been done on practical lines. 



Interest has however been awakened, 

 experiments with leguminous and other 

 plants are common, and I hope to be 

 able to show that one plant may be 

 used with both economical and other 

 advantages. 



In this article it is not proposed to go 

 into the theoretical side of the matter. 

 What at present appeals most to people 

 is the cash expenditure for keeping 

 weeds down— or out, the cheapest way 

 being naturally the most popular one, 

 and weeding will here only be dealt with 

 from this point of view. 



Of course with virgin jungle properly 

 dealt with from the start, the weeding 

 bill should never look high, and old 

 established estates will perhaps naturally 

 adhere to their old method. 



Most plantations have however in one 

 corner or another a block of old aban- 

 doned paddy-fields or Malay kampongs, 

 and in such places a cheap method of 

 getting rid of weeds is much wanted. 



I, at any rate to get, have had the bad 

 luck of getting a few acres of such land 

 indifferently burnt, and all the planters 

 who have seen it have invariably 

 advised me to changkol the whole place 

 at a cost of anything between $20 and 

 $60 an acre. 



For various reasons this work was not 

 done, but I believe most planteis will 

 from experience be able to state, if the 

 above price is correct. 



For some time experiments have had 

 been carried on with a view to introduce 

 a plant, which would be able to keep 

 weeds out, and at the same time itself 

 benefit or at least do no harm to the 

 rubber trees, and for this purpose I have 

 found Tephrosia purpurea admirably 

 adapted. 



As this plant, seed of which was kindly 

 presented me by Dr. Treub of Buiteu- 

 zorg, is new to the F. M. S., some infor- 

 mation of how it was established may 

 be of interest. 



The first plot was only 20' by 40' and 

 was planted up with one or two seeds in 

 every square foot. The place was then 

 clean of weeds but had not been chang- 



38 



