March, 1909.] 



215 



Saps and Exudations- 



While the use of arsenite of soda was 

 first investigated, as mentioned in ray 

 last report for the eradication of the 

 most pestilent weed, lalang (Imperata 

 arundinacea), this method of getting rid 

 of w T eeds is still more efficacious in the 

 case of other weeds submitting a larger 

 and flatter surface to the spray. The 

 leaves are all killed within 18 hours, and 

 should be left to rot on the ground and 

 not pulled out or scraped away ; by 

 this means the soil i« protected from 

 rain and sun, and if the plant becomes 

 green it can be again sprayed. The cost 

 of this method of destroying weeds 

 necessarily varies with the character of 

 the fields to be sprayed, but in most 

 cases with hand atomiser sprayers the 

 cost should not be 50 cents per acre 

 where very weedy, and on ordinary 

 fields probably not more than 10-15 cents. 



A series of experiments near the labora- 

 tories of the department are in progress 

 to estimate the cost of eradicating lalang 

 by the following processes : — 



1. Spraying with arsenite of soda ; 



2. Digging and picking out all roots 



3. ,, re-chungkoling ; 



4. The introduction of Passiflora 

 fcetida, " wild passion flower," a 

 vigorous creeping plant which 

 smothers lalang and can itself be 

 easily removed. 



These are being carried out in various 

 ways on some ten 1-acre lots and the 

 exact cost in each case recorded. The 

 lalang, which has been in possession of 

 the fields for some years, is tall and 

 vigorous, typical of thousands of acres 

 ■which are to be found throughout the 

 Peninsula. 



HINTS ON PLANTING CASTILLOA. 



By F. G. Scott. 



On ordinary Cacao soils Caslilloa elas- 

 tica should be planted about 20 ft. apart, 

 and on very rich soils about 30 ft. 

 When possible, holes should be prepared 

 in March, about 3 feet deep aud 2 feet 

 wide, and filled with equal quantities of 

 earth and stable manure which would 

 help the young plants to become quickly 

 established. They should be put in about 

 three months after preparation of the 

 holes so as to allow the earth to settle, 

 which would be in June, the beginning 

 of the rainy season when the field has 

 received one or two showers, for if plant- 

 ed later it might become too saturated 

 and would tend to rot the young root- 

 lets, consequently killing the plants, 

 which is often the case when forming 



estates. If the plants are in bamboo 

 pots it should be always removed as it 

 allows the plaut to spread its roots much 

 quicker. The best way to remove the 

 pot is to take hold of it in the left 

 hand and a cutlass in the right ; allow 

 it to be at right angles to your body, the 

 plant facing you, and give three fairly 

 quick sharp blows with the cutlass so 

 as to strike it in a different place each 

 time ; then remove the three broken 

 pieces together with the small gravel at 

 the bottom of the ball, taking care that 

 the earth does not break up. 



Castilloa elaslica grows best under 

 partial shade, and would thrive well 

 along the boundaries of a cacao estate, 

 provided they are planted at proper dis- 

 tances and not intended as wind-breaks. 



Where trees are exposed to wind 

 Funtumia elaslica could be planted 

 with advantage, not only as a wind- 

 break but as a rubber-producing plant. — 

 Trinidad Botanical Department No. 60, 

 October, 1908. 



CAMPHOR AND ITS BY-PRODUCTS. 



Distribution of Camphor Trees. 



The growth of this important tree is 

 limited in Japan to the south of 36° north 

 latitude. On the south coast of the Main 

 Island, Shikoku, and Kyushu, the trees 

 are met with only in the compounds of 

 shrines or temples, or in gardens, where 

 they have been preserved from felling. 

 As the distillation of camphor became 

 common, the felling of the trees in- 

 creased, and forests of this valuable trees 

 were greatly reduced in area, but a few 

 old specimens were fortunately pre- 

 served. 



The propagation of this tree is in no 

 way neglected, so that the production of 

 camphor will increase in the course of 

 years. Formosa has at present an exten- 

 sive supply of these trees, as there, in 

 districts not yet explored, huge trees are 

 still found in their primordial luxuri- 

 ance. 



Camphor-tree Planting. 



In raisiug camphor trees, seedlings 

 are obtained by sowing the seeds 

 directly in a wood. Small holes are 

 dug in an already well-grown forest 

 of evergreen oaks or red pines, and 

 four or five seeds are put in each 

 hole. The shelter of the trees favours 

 the growth of the seedlings. 



In fifty years trees so planted will 

 attain a diameter of one foot when 

 they are large enough for the produc- 

 tion of camphor. In many places 

 attempts have been made to grow 



