440 



The next part of the paper deals with the various pests of rubber 

 plants the first of which attacking Hevea is Corticium Javanicum the 

 Javanese Jamur upas (Djamoer oepas) which the author considers the 

 worst pest. A remarkably good photograph is given of this destructive 

 fungus. It has already been described in the Bulletin. 



It not only attacks rubber but is most destructive to coffee, and 

 also attacks other plants. It attacks trees of all ages but is most 

 destructive to plants of 1 2 to 2^ year's age. It usually appears on the 

 bases of the lower branches, but also and here it is more dangerous on 

 the trunk at about the height of the first branches. It first appears as a 

 pink or nearly white spot, and grows, thickens and becomes brighter 

 rose color. It spreads and eventually surrounds the trunk or branch 

 killing it. The edge of the mass of fungus is merely superficial but the 

 mycelium filaments of the centre penetrate to the wood. The bark 

 becomes porous, broken up and soft. The small beetles then attack 

 the decaying portion and finish the work of destruction. The author 

 made small wounds in a young Hevea bark and inoculated them with 

 spores of. Corticium taken from a coffee tree, and the growth of the 

 fungus proved that the disease on the coffee was identical with that of 

 the rubber tree. 



The fungus appeared in the west monsoon, and it was clear that 

 the dampness of the air favoured the growth much. In a plantation 

 at Bandong, of about 180,000 trees, two years old, during the rainy 

 season about 30 trees were attacked each month, about 500 trees in 

 all. In the dry season only one or two here and there were attacked. 

 The disease was contagious, and the fungus passed from tree to tree, 

 and from coffee bushes to Heveas. The author strongly condemns there- 

 fore the habit of planting Hevea among old worn out diseased coffee. 



The remedy is to cut away all parts attacked. The infected 

 portions should not be carried through the plantations but burnt on 

 the spot. Rubber stands operations of this nature very well. By 

 lopping and tapping where necessary in the above mentioned Bandang 

 Estate only about 20 trees attacked were lost. He points out however 

 the risk in tapping larger sized trees, due to the wound made being too 

 large, and allowing water to settle on the tops and permitting fungus 

 spores and notably Corticium spores to grow there. In the case of an 

 attack he recommends spraying the neighbouring trees with Bordeaux 

 mixture. 



The next fungus described is what he calls the white root fung- 

 us (champignon blanc des racines) met with in Java and Sumatra 

 and as dangerous as the Corticium. This attacks trees of all ages but 

 especially those of 1 or 2 years old, which appear quite healthy 

 and suddenly commence to go brown at the top, the leaves later 

 became yellow and fall. It is difficult often to know whether this is 

 due to the normal leaf-fall or to the disease. A little later a wound 

 in the bark only lets a little latex exude and later all flow ceases 

 from the base upwards to the top. In a few days the plant is quite 

 dead. The roots are found to be covered with more or less strongly 

 developed cords, white, leathery elastic and matted, branching and 

 eventually quite covering the root. At first the strands are found on 

 the tap-root, which is destroyed; later it spreads to the side roots. 



