521 



dead tree was noticed. When unavoidably the lines of the scheme 

 cannot be fully followed, the inner trench at least should be made 

 and the work recommended to be done within it carried out. This 

 curtailment must not be taken as recommended except in special 

 circumstances, and only as an irreducible minimum. 



Owing to the amount of dead wood in and on the surface soil of 

 an ordinary estate and to the length to which the lateral roots of para 

 trees so quickly spread, there is little use in merely turning the fungus 

 covered roots of the dead tree up to the sun and digging a hole about 

 two feet square and two feet deep for a new "supply." Notwith- 

 standing advice to the contrary this is too often done. The old roots 

 and dead wood around are most likely supporting the fungus, and as 

 soon as these are reached by the young roots of the " supply " infec- 

 tion occurs, and in a couple of months there is need to put in another 

 " supply." 



The presence of root disease on a tree may be detected two months 

 or more before it drops its leaves or is blown down : if it is shaken it 

 will be found to be markedly loose in the ground. Once a case of this 

 disease has been noticed in a field a good coolie might test the trees 

 say once every week or fortnight marking those he noticed loose for a 

 closer examination by the manager. If the soil is carefully cleared 

 away a little round a suspected tree the fungal threads will be noticed 

 on one or more roots if root disease is present. When the tap root is 

 not attacked it may be possible to kill the parasite by cutting off and 

 burning the diseased lateral roots and forking in plenty of lime round 

 the tree. It is safer and surer to take out the tree and proceed in the 

 way recommended above, as the source of the trouble is probably still 

 existent on some neighbouring stump. I think that the idea of exami- 

 nation by a coolie might be extended further and a periodical examina- 

 tion, say once a month, made of all trees from one to three years old. 



With regard to the putting in of the " supplies," this is dependent 

 somewhat on the season, but at least eight or ten weeks should elapse 

 before replanting. The trenches should be left open about three 

 months; if any of the suspected ring has been infected, it will probably 

 show itself before that time, but it would be wise to make an examina- 

 tion by clearing away the soil from the root to a depth of a foot or so 

 when the fungal threads will be seen if the tree is infected. The upper 

 six to ten inches of the tap root are first attacked. 



On account of the large continuous areas under rubber and our 

 uniformly moist climate an apparently insignificant disease may easily 

 become epidemic if not grappled with in time. Planters should there- 

 fore immediately report unhealthiness among their plants. Diseased 

 specimens should be sent and full information given. Unfortunately 

 letters usually tell little more than that the plant died. It is better to 

 err on the side of saying too much ; nothing should be omitted because 



