518 



possible that a "bracket" fructification is formed, and it may be dis- 

 covered when the life history of the parasite is more fully investigated. 

 The planter will then know the cause of the ill health or death of a 

 tree when he notices the "brackets" on adjoining dead wood. On 

 the other hand the fruits may be so small as to be invisible to the 

 naked eye ; and they may be found on the living plant only or on dead 

 wood only. 



This parasite appears to belong to the dangerous class of facul- 

 tative parasites; that is it can live on dead wood (saprophyte), and if 

 need be on on living wood (parasite). 



Fomes semitostus, a "bracket" fungus, has been reported as a 

 source of root disease here and in Ceylon. I have found it on only two 

 occasions, and have not been able to connect it with the disease under 

 discussion, 



Eemedial Measures. 



Though cure is almost impossible prevention of further infection 

 is fairly easy. Owing to the absence of seeds (spores) infection must 

 take place underground, and only when a para root is in contact with 

 a jungle stump or log supporting the parasite. The under-ground 

 strands of threads of many fungi, such as Agaricus melleus, a dangerous 

 parasite on oak trees in forests of the temperate zone, travel for con- 

 siderable distances through the soil, but seldom at as great a depth as 

 two feet. The present fungus appears to have such a capacity in only 

 a limited degree. I have never found strands more than a foot from a 

 piece of root or decaying log ; but the soil of a rubber clearing, es- 

 pecially when it is peaty, is full of roots and all kinds and sizes of 

 decaying wood. The spread of the disease is likely to be much slower 

 than with those which attack leaves or other above-ground parts, where 

 wind, animals, and human agencies assist the dissemination of spores. 

 On the other hand living in the soil secures it from the destructive 

 influences of sunshine and, in our climate, of drought. 



In many cases where close planting has been followed, managers 

 pay no attention to trees dying here and there over the estate, looking 

 on it rather as a premature removal of what may have to be cut out 

 later on. Such indifference is not wise, and may have costly results. 

 Except when stagnant water is the source of trouble, the death of a 

 young tree is, according to my experience, generally due to root disease, 

 which can be easily identified by the planter who is on the look out for 

 it. If preventive measures are not taken the disease spreads and 

 adjacent trees begin to die off. It is impossible to be too insistent 

 upon the importance of treating every diseased tree as a possible centre 

 from which many more trees may be infested. 



As already mentioned the planter's efforts must be directed to 

 prevention. The diseased area must be isolated, and precautions taken 

 against the possibility of the disease spreading. 



Attempts to cure are hardly practical, if indeed cure is even possi- 

 ble. An application of lime to a tree but slightly attacked may some- 

 times be successful. Lime is alkaline and an alkaline medium of this 



