and Magazine of the Ceylon Agricultural Society.— March, 1910 



287 



"die-back " frequently continues down the stem 

 until it reaches the root and the tree is killed 

 outright. It is not, therefore, a very serious 

 disease in the case of young trees, provided 

 that they are not left to take care of themselves. 

 After dealing with the fungi which originate 

 the disease and with the latter's symptoms, 

 Mr. Petch states that the tops of trees at- 

 tacked by " die-back," having been cut oft' 

 below the dead part, must be burnt ; and 

 he goes on to point out that if the diseased 

 stems are left lying about the planta- 

 tion they will hatch out myriads of Botryo- 

 diplodia spores, all ready to attack other 

 trees when they get an opportunity. Botryo- 

 diplodia elasticae is an extremely widespread 

 fungus, and it would be quite impossible to 

 eradicate it, but there is no need to encourage 

 it by neglecting to remove the dead stems. It 

 grows excellently on all dead stems of Hevea, 

 no matter what the cause of death, and any 

 one can obtain specimens of the fungus by 

 cutting down a healthy tree and leaving the 

 stem on his verandah for a fortnight. It 

 is fortunate that the fungus is not a direct 

 parasite of Hevea, but can only attack it 

 through wounds or dead branches. The dis- 

 eased part should be cut off with a slightly 

 sloping cut. It should not be too oblique, 

 or the upper thin edge will die. If the dead 

 portion is large, it should be cut down in 

 pieces, so as not to injure the lower branches. 

 The cooly will no doubt prefer to use a catty, 

 but if so the stem should be finally trimmed 

 off with a saw to get a smooth surface. The 

 removal of dead branches, which may afford an 

 entrance for Botryodiplodia and other fungi, 

 will have to become part of the general routiue 

 of a rubber plantation, and some coolies should 

 be taught how to do this properly. The removal 

 of a large branch requires three cuts with a saw. 

 The first is made, about a foot away from the 

 trunk, on the under surface of the branch and 

 about half-way through it; the second is made 

 from the upper surface three inches further 

 from the trunk, and continued until the branch 

 breaks off. The double cut prevents any damage 

 to the main stem. Finally, the stub must be 

 sawn off as close to the stem as possible; it must 

 be cut off flush with the stem, not perpendicular 

 to the branch. This may give a bigger wound, 

 but it will heal completely, whereas the bark 

 will uever grow over a triangular stub. The cut 

 surface must be tarred to prevent the entrance 

 of fungi. The heartwood of any tree is prac- 

 tically dead, and, if exposed, can be readily 

 attacked by many fungi which c<uiid never 

 obtain a footing on the tree under other circum- 

 stances. The progress of such fungi is slow, 

 but the tree ultimately becomes hollowed out 

 or weakened to such an extent that it is broken 

 by wind. Coal tar should be used for covering 

 the cuts. It is much more permanent than 

 Stockholm tar and more effective against fungi. 

 Of course, the cooly should not be allowed 

 to use so much that it runs over the healthy 

 bark, and to avoid this it is better to U3e it 

 cold. Hot tar is best, but there is more danger 

 of injury. The cut surface should be as dry 

 as possible, but it should not be left exposed 

 for more than a day before being tarred. 



These two points may conflict in practice, 

 and it is a matter for compromise. To avoid 

 the disease caused by the fungus attacking 

 stumps the holes where the stumps die 

 should be lined, and supplied with basket 

 plants. Mr Petch follows the above with an 

 interesting account of the distribution of the 

 fungus and the conclusions he draws are that 

 dead branches should be regularly removed 

 and burnt, in both cacao and hevea plantations, 

 that it is unwise to allow albizzias planted in 

 tea or rubber to grow into large trees and then 

 to cut them down, that, when albizzias three 

 inches in diameter are pruned at a height of 

 three or four feet, the cut surface of the stem 

 should be tarred to prevent them dying back, 

 and that to interplant cacao and rubber is un- 

 sound, seeing that they are attacked by the 

 same fruit, stem, and root diseases. The cir- 

 cular is concluded by a reference to climatic 

 leaf fall in hevea which in some respects 

 resembles "die-back." 



CAMPHOR ON THE GOLD COAST. 



A Rkcent Peradeniya Visitor's Report, 

 An introduced crop that gives exceptional 

 promise is camphor (Cinnamon camphora), plots 

 of which have benn established at three of the 

 agricultural stations. It shows very satisfactory 

 growth, as will be seen from the notes on the 

 stations, and is far better than trees of similar 

 age in Ceylon, where, to a limited extent, it is 

 now being cultivated and the camphor extracted 

 by distillation and sublimation from the leaves 

 and twigs. This is a form of cultivation that 

 might profitably be taken up in this Colony 

 by some of the more intelligent planters. Japan 

 has hitherto practically held a monopoly in this 

 product, the trees yielding it being indigenous 

 to the forests of Formosa, and it is only within 

 the last fewyears, owing apparently to an in- 

 sufficiency of supply and consequent increase in 

 price, that its production has received scien- 

 tific investigation. Camphor is an important 

 element in certain manufactures, notably 

 celluloid, and in the manufacture of explosives, 

 and unless synthetic camphor can be manu- 

 factured at a price below that at which the 

 natural product can be produced, it is reason- 

 able to suppose that this may prove profitable 

 to cultivate. Cinnamon also grows well and 

 could be produced on a commercial scale should 

 it be remunerative enough to do so ; but at the 

 present prices 1 could hardly recoraend it. — 

 Official Be port on 1908, by W. S. Tudhope, 

 Director of Agriculture. 



TOBACCO GROWING IN U.S.A. 



A report on experiments in tobacco growing 

 which have been carried on at the Agricultural 

 Experiment Station of the Li niversity of Wiscon- 

 sin states that the use of manures free from 

 chlorine was found not to exert any detrimental 

 effect on the burning quality of the leaf. — West 

 Indian -Agricultural Hews, Dec. 11. 



