PARA RUBBER. 149 



ether fruit while the original fungus is flourishing, resting spores are 

 formed in the dead frail . These are liberated when the fruit decays, 

 and thus serve as a source of infection to the following crop. In 

 this way the fungus bridges tin* gap between the crop. 



The most effective way of fighting the fruit disease is to collect 

 all dried fruits which arc on the trees and those which have fallen 

 to the ground and burn the lot on the spot. On the average rubber 

 estate there can be no real objection to burning such small quantities 

 of fruits as this treatment involves. 



Stem Diseases. 



Fungi. — In his account of canker (Xectria) of Para rubber Tar- 

 ruthcrs points out that a parasitic fungus occurs on (he stems and 

 branches, which may prove fatal to the trees. The area attacked by 

 the fungus can be detected often by the change of colour of the bark 

 or by the exudation of the latex. When, however, the fungus 

 has got a firm hold of any local patch of tissue, the late\ tubes I" 



quite empty and dry up. so that it not only threatens the life 

 of the tree, but also robs the planter of the latex or rubber for which 

 the tree is being cultivated. It is necessary that all cankered areas 

 should be excised and the tissue burnl on the spot. All the dis- 

 coloured areas should be removed, even if the woody tissues below 

 the cambium are permanently damaged in the operation. In some 

 rases it is true that the cankered area is. by means of a layer of cork . 

 prevented from extending to other parts of the stem, hut it is unwise 

 to leave the matter to chance. 



The disease mentioned above has been found'by Carruthers on 

 "almost all pails of the tree except the young branches ami the 

 roots." but even these parts have now been shown to be attacked 

 by other fungi. 



Petch* has observed a blackening of green stems of Para rubber 

 trees to be clue to a fungus which produces a network of dark- 

 coloured threads on the exterior. 



A bark fungus has been described in the Straits Agricultural 

 Bulletin. t November, L905: — " This fungus takes the form of a 

 pinkish-white mass, coating the hark irregularly so as to have an 

 appearance often of hieroglyphics. Attacking usually the upper 

 branches or occasionally the stem, it <piite destroys the hark and 

 causes the death of the wood beneath. Fortunately it is easy to see 

 from its conspicuous whitish colour, and easily dealt with by destroy- 

 ing infected branches, and in the case of the trunk being affected by 

 scraping it off and treating with copper sulphate and lime" 



Grey blight on the stems of seedlings has also been observed by 

 Petch. The fungus forms a white zone about an inch long just 

 above the surface of the ground. The stems lose their pith, 

 become hollow, aud the plants die. 



* T. Fetch. Mvoolopml Note-. Tropical Agriculturist, August, 1905. 

 t Straits Agricultural Bulletin, November, 1905. 



