380 



The Supplement to the Tropical Agriculturist 



MrPetch :— Certainly, Only before I started on 

 the other side I would sterilise every tapping knife 



Mr Masefield : — When you cut out this 

 diseased section, you do not recommend tarring 

 or treating it in any other way ? 



Mr Petch : — I would not tar the surface in"a 

 case like this. I would always tar where you 

 cut off the branch of a tree. If you simply 

 take off the bark, there is no need to tar because 

 the spread of the bark is more vigorous. 



Mr Cantlay : — Can you suggest anything 

 else instead of tar ? 



Mr Petch : — Tar prevents the decay of wood; 

 and it is a splendid waterproof protection. 

 Fungi cannot get through it. I do not think 

 you can look to anything better than coal tar 

 to apply to a cut. 



Mr Wood : — The disease does not pass from 

 tree to tree unless it is carried by the tapping 

 knife which is not sterilised. 



Mr Petch :— It 



CAN BLOW OFF, 



but it is chiefly spread by means of the knife. 



Mr Williamson : — You think it is a mistake 

 to lop big trees on the estate to save your tea? 



Mr Petch :— It is a mistake unless you tar 

 the ends of the branches lopped off. Lopping 

 and taking off the leaves will also rather spoil 

 the feeding capacity of the tree. As long as 

 you tar the lopped ends you are safe. Coal tar, 

 of course. We had a very good example in 1904. 

 In that year two of the Government plantations 

 were treated for canker. In a large number of 

 cases the trees were stumped, and in some cases 

 they were cut off at a fork. Fungi have now 

 attacked the cut surface. The heart wood of any 

 tree is just as good as dead, and where it has 

 been exposed, fungi have entered the trees and 

 they have snapped off. 



Mr. Duncan : — Cutting of branches is not an 

 ordinary matter. 



Mr. Petch: — Why not? 



Mr. Duncan: — The plants are too old. 



Mr. Petch : — If they are more than 2 inches 

 in diameter I will always tar. There is another 

 example we had of 



STUMPING TREES 



about twelve years old which were in the way of 

 a road which was to be made through a planta- 

 tion. The Superintendent took off the trees, 

 cut off the tops and transplanted them. In one 

 case out of five of the branches forking from the 

 main stem only four were tarred at the lopped ends 

 for some reason or other, and the fifth left untar- 

 red. The four tarred branches were all right, but 

 the fifth untarredone commenced to die back one 

 foot within a year; and if that is not cut, and the 

 surface tarred, it will die back until it enters 

 right into the tree and the whole will collapse. 



Mr. Bamforth : — Lopping does not stop the 

 flow of latex ? 



Mr. Petch : — I do not think so, unless you 

 lose the latex you would have got from the 

 lopped-off branch. Lopping will stop the growth 

 of the tree to some extent. The tree will not 

 grow as rapidly as before and therefore you will 

 get a smaller quantity of latex. 



Mr. Cantlay : — What about fungi spreading 

 from the dead tree to the living ones ? 



Mr. Petch :— The fungi could not get in at the 

 end of the tarred branch. 

 Mr. Wood : — If you leave a 



FALLEN TREE LYING ON THE GROUND, 



what will happen ? 



Mr. Petch :— You will first of all hatch 

 out the "die back" fungus and secondly root 

 disease. So much has been written about the 

 root disease that there is no necessity to go into 

 it now. This is the well-known "Brown Root 

 Disease " which is easily identified by its habit 

 of cementing sand, soil, and stones to the roots 

 of the trees attacked. 



Mr. Bamforth : — After cutting off, you must 

 burn the cuttings ? 



Mr. Petch :— If you cut off the " die back " 

 or "pink disease," you must burn the portions 

 cut of, instead of leaving them on the ground. 



Mr. Masefield : — As regards Stockholm tar, 

 will it not answer in the case of treating the cut 

 off surfaces ? 



Mr. Petch : — Stockholm tar is a vegetable tar, 

 and I do not know if it will answer for canker. 



Mr. Masefield :— It is a mistaken idea among 

 planters that Stockholm tar has to be used. 



Mr, Petch :— Coal tar, of course, is the tar to 

 be used. The difficulty comes in the case of tea. 

 What was found suitable in the case of tea was 

 sought to be made applicable in all cases. If you 

 tar the growing bark of tea with coal tar it will 

 kill that bark ; if you tar cut ends, it will not kill. 

 Some 15 or 20 years ago somebody 



scattered coal tar all over his tea 

 bush and found it was bad for it, and that idea 

 continues to the present day. (Laughter.) There 

 is no reason why you should not use coal tar, 

 which is very much better than Stockholm tar. 



Mr. Cantlay :— In this case (specimen shown) 

 the canker came on after you resumed tapping 

 in the wet weather? 



Mr. Petch : — You can have canker on the un- 

 tapped. In the present year it is coming on 

 more in the tapped area. 



The Chairman : — Mr. Petch has finished his 

 address and we have now to return him a hearty 

 vote of thanks. 



Pricking and Tapping. 



Mr Duncan — with the permission of the Chair- 

 man—asked another question or two. Mr Petch 

 had written a rather interesting paper on tap- 

 ping ; he wished for information with regard 

 to the use of the pricker and the tapping knife. 



Mr Petch — said that he could only tell Mr 

 Duncan to go on experimenting with the sys- 

 tems. He instanced the case of a gentleman in 

 Ceylon who was very strong on the use of the 

 pricker, but he had not used the pricker, after 

 trying it, on the estate in his charge the last two 

 years. (Laughter.) 



Mr Duncan — remarked that Mr Fetch's state- 

 ment had been that renewed bark under the 

 pricker did not carry latex cells, that, given 

 plenty of pricking, it would stop the development 

 of latex entirely 



Mr Petch :— There is a qualification to that. 

 We have examined renewed bark under the 

 pricker marks up to an age of six months, 

 and from what we have gathered in the firBt six 

 months your conclusion is practically correct— 



