566 



The Supplement to the Tropical Agriculturist 



COCONUT PALM DISEASE EN BORNEO- 



We have lately received from a correspon- 

 dent, in Borneo, an account of a serious disease 

 in coconuts, which bears so great a resemblance 

 to that known as bud-rot, which has hitherto 

 only been met with in India and Ceylon, at 

 least in this part of the world, that it seems 

 highly probable that it is identical. Our corre- 

 spondent, Mr E Hose, describes it as follows : 

 "The leaves turn yellow and the fruit, if there 

 is any, hangs limp, the leaves drop down and 

 gradually die, the stem of the tree gets thinner 

 and thinner near the top, then the centre shoot 

 drops out, apparently having rotted ; insidethe 

 heart, at the top, it is like rotten wood-mud. It 

 seems to attack trees of any age. Trees on wet 

 or dry land are affected by it. According to 

 native stories, it has only put in an ap- 

 pearance since the last two years." A very 

 valuable and full account of an exactly 

 similar disease is published in the Bulletin 

 of the Agricultural Research Institute of 

 Pusa, TSo. 9, March, 1908, by Mr E T Butler, 

 the Imperial Mycologist. He says : (p. 5) "Asa 

 general rule, the first indication that a coconut 

 palm is attacked is the opening out of the outer 

 leaves from the head. The leaf stalk becomes 

 slightly flaccid and the weight of the leaf causes 

 the whole to drop. Then the ends of the pinnae 

 or leaflets at the extremity of the leaf become 

 flaccid and hang down almost vertically, this is 

 accompanied with a loss of colour, the dropping 

 and discolouration of the leaflets then extend 

 gradually backwards to the whole leaf. Later 

 on. the tips of the leaflets turn yellow and dry 

 up", followed gradually by the entire leaf, which 

 eventually hangs down, withered, from the 

 crown. The attachment of the leaf sheath 

 to the tree is weakened so that the outer 

 discoloured leaves can be easily torn from the 

 crown one after another, or many together, all 

 the leaves are similarly affected. . . . Gradually, 

 as the palm weakens, new leaves that are put 

 out are smaller than of old. This is apparent 

 even before they unfold from the bud and re- 

 sults in the central shoot which is merely the 

 unopened leafbud becoming stunted and pallid. 

 Later on, it begins to wither and the upper 

 tree part turns brown. Eventually it may dry 

 up altogether, but this may not occur for many 

 years. The top of the stem and the white 

 internal part of the crown are quite normal, 

 except in old cases just before death, when the 

 latter rots. One of the conspicuous marks is 

 the way the nuts are injured. Even in the 

 first year or two the nuts are affected. They 

 are fewer and smaller than usual, on splitting 

 the husk is found unaltered and usually the shell 

 also. The white kernel is, however, shrivelled 

 and' indurated and copra prepared from it is 

 said to be deficient in oil. The fluid inside is 

 reduced in quantity, and is altered in quality, 

 becoming unpalatable to drink. In later stages, 

 a large proportion of the nuts drop in an imma- 

 ture condition. In more severe cases the spa- 

 thes are unable to burst out at all or if they do, 

 rot away early and the palm becomes barren." 



This description fits well the accoant from 

 Borneo, and seems certainly to be of the same 

 disease, and as it haB thus approached so 



near to the Malay Peninsula it is very desirable 

 that a watch be kept for its appearance here. 



The disease is not situated in the bud of the 

 tree, but in the roots, which are attacked by a 

 parasitic fungus belonging to the genus Botryo- 

 diplodia, at least this fungus appears always to 

 occur on the rotting roots of trees affected by 

 this disease. The destruction of the lateral 

 roots cuts off the water supply of the palm so 

 that the bud dies of drought and starvation. 



The death of the palms is very slow. "Young 

 palms may be killed in five years, but this is 

 exceptional. Eight or ten years appears to be 

 a more usual period while in many cases the 

 disease progresses enough to cause barrenness 

 but fails to kill the tree outright. Thus, in one 

 large garden only two hundred coconut palms 

 were in bearing out of about two thousand, 

 while the deaths were not numerous." 



" The disease is worst in heavy alluvial valleys 

 and poor laterite hill soils. It is least severe in 

 the sandy soil of the littoral. There is plenty of 

 evidence that the disease is infectious. A palm 

 evidently affected and brought from an infected 

 district ten years ago was planted in a garden 

 where the trees were all healthy. A few years 

 later, it began to turn yellow and others near 

 by Wbre attacked ; now thirteen trees are 

 affected and the original one is dead and the 

 disease has spread to neighbouring gardens." 



The disease attacks not only coconuts, but 

 betelnuts, and caryotas. The treatment recom- 

 mended is destruction of all diseased palms 

 whether they be only just attacked or practically 

 dying. The roots should be dug out and with 

 the stem leaves burnt at once. Lime, preferably 

 quick lime, should be well due into the infected 

 spot, and the ground frequently dug over to 

 break up and aerate the soil. If necessary, the 

 soil should be drained, as undrained or insuffi- 

 ciently drained soil affects the roots injuriously 

 and the weeds on the ground destroyed, and ma- 

 nuring with cow dung or nitrogenous fertilizers 

 should be tried. No plants should be planted 

 in the infected spot for a year after the re- 

 moval of the diseased trees. 



As in the case of most at least of these 

 ground root fungi, the progress i& compara- 

 tively slow, so that it should be possible if 

 taken in time to stop an outbreak with the loss 

 of a very few trees, but in order to do this 

 plantations must be carefully examined, and 

 any tree exhibiting the symptoms described 

 above should be destroyed and removed as 

 quickly as possible. 



There is another bud-rot disease in India pro- 

 duced by the fungus Pythium palmivorum in 

 which the shoot is actually attacked by the fun- 

 gus. The withering of the shoot at an early 

 stage is the most characteristic feature. The 

 first symptom is the turning white of a whole 

 leaf towards the centre of the crown, the bud 

 then turns white, rots and the crown falls off, 

 the whole of the 'cabbage' becoming converted 

 into a putrid, foul-sniolling mass. The whole 

 palm is killed in a few months, and recovery is 

 very rare. But these symptoms do not seem 

 to be identical with those of the Borneo disease. 

 It appears chiefly to attack the palmyra palm 

 in India but also areca and coconut. — Ed.— 

 Straits Agricultural Bulletin for May. 



