A. Sharples 173 



FUTURE POLICY AND CONCLUSION. 



It is an accepted fact that pests and diseases are a constant menace 

 to all plantation industries. The potential dangers to the Rubber Plan- 

 tations in Malaya are becoming more manifest each year, and the menace 

 is doubly dangerous because of the comparative immunity of the planta- 

 tions up to date, which has lulled responsible persons into a false sense of 

 security. Many significant facts have been brought to light during the 

 last two years. A few cases of serious attacks of root disease in rubber 

 plantations might be quoted : 



(a) On one estate, a block of 6-7 acres of sixteen year old rubber was 

 examined — sixty trees to the acre. A casual inspection revealed 120 trees 

 attacked by U. zonata. More have since been found. 



{h) The Grovernment estate behind the offices of the Department of 

 Agriculture at Kuala Lumpur carries about seven acres of fifteen years 

 old trees. A fair number of cases of U. zonata were known, but only one 

 small group of six trees was known to be affected with "wet root-rot^." 

 To obtain specimens and observe the disease below ground, this group, 

 together with the neighbouring trees, was opened up. It was obvious 

 from the commencement that the subterranean spread was much greater 

 than at first anticipated. Two hundred and twelve trees were opened up, 

 and forty per cent, showed diseased roots (i.e. wet root-rot). The matter 

 was so serious that at the request of the Advisory Committee to the 

 Department of Agriculture, the whole of the seven acres of old rubber 

 had their roots exposed. Over the whole area, in which 700 trees were 

 examined, twenty per cent, showed diseased roots. 



(c) A third illuminating case was noted some months ago. A wind 

 storm, locally known as "Sumatra," swept over a portion of one estate, 

 and a large number of seventeen year old trees were blown over. Of these 

 prostrate trees, only three showed healthy roots; these were without tap 

 roots. A few of the fallen trees had been treated previously for U. zonata, 

 but by far the great majority which were not suspected to be suffering 

 from root disease, had U. zonata attacking the roots. A few cases of 

 branch infections with U. zonata and a few roots with wet root-rot, were 

 also found. When the place is cleared, huge gaps must be left in the 

 wind swept area. The manager is quite certain that any other portion of 

 the old rubber subjected to a similar storm would show a larger number 

 of unsuspected cases of root disease. This, and the case quoted im- 

 mediately above, shows the insidious spread of these root fungi on old 



' ^ Belgrave, W. N. C. "A Root disease of Plantation Rubber in Malaya." Agr. Bull. 

 Fed. Malay States, Vol, iv. No. 11. Aug. 1916. 



