310 



AGRICULTURAL BULLETIN 



OF THE 



STRAITS 



AND 



FEDERATED MALAY STATES. 



No. 7.] JULY, 1909. [Vol. VIII 



A NEW FUNGUS-PEST ON PARA RUBBER. 



I have recently received from a planter in Perak por- 

 tions of the branches and boughs of Para rubber trees des- 

 troyed by the attacks of a bark fungus hitherto unknown 

 to me. The attack commences on the shoots which pre- 

 sently turn black and die, and the disease continues to des- 

 cend to the trunk of the tree which eventually perishes. On 

 examining the bark attacked, there can be seen numerous 

 raised spots, which split and show a black fungus pushing 

 out in the crack. In some places the bark is quite thickly 

 marked with short straight cracks parallel to the axis of 

 the branch. In older parts of the branch the grey bark is 

 covered with larger elevated patches black in color and 

 looking as if soot had been thrown on the tree. The cam- 

 bium is dead and black, the wood dry, and soon perishes. 



Examination with the microscope shows that in these 

 black patches are round spaces (perithecia) imbedded in a 

 black mass, (stroma) from the interior of which are dis- 

 charged large numbers of oval spores, mostly transversely 

 divided. The fungus evidently belongs to the group of 

 Ascomycetes and appears to me to be allied to a genus 

 €ucurbitaria parasitic on the Laburnum in Europe in much 

 the same way as this fungus attacks Hevea here. 



The correspondent who sends the specimens writes, 

 "Trees with apparently the same disease are dotted about 

 the Estate singly and in groups. 1 am cutting down all the 

 diseased trees to the point where the latex exudes healthily. 

 This cutting back appears to stop the disease as the stumps 



