DISEASED BANANA PLANTS. 



The Secretary of the Agricultural and Industrial Association of Fiji communicated with the De- 

 partment of Agriculture of N. S. Wales, under date June 16th last, notifying the despatch of a case 

 of diseased banana plants, and asking the Department to interest itself in having the disease thoroughly 

 investigated. From this letter it appears that the disease has defied eradication by the banana plan- 

 ters of Fiji. The evidence seems to show that it affects the young plants, that after they are set and 

 begin to grow the outer leaves begin to turn brown, droop and die, and that the succeeding leaves do 

 the same as they reach from four to six inches in length. The plant continues growing in this way 

 for several years without much increase in size, instead of growing as it should to a height of from six 

 to twelve feet, and producing fruit. The disease is said to be very serious, although sufficient infor- 

 mation has not yet been furnished to indicate the exact extent of loss. 



In connection with this matter it may be mentioned that the Department also received from Cla- 

 rence River some six months ago a specimen of diseased banana, but as this specimen consisted of a 

 grown plant after it had been cut down, it was not possible to make out very much. It is possible 

 however, that this disease from Fiji is the same as sent from Clarence, and inasmuch as investigation 

 has shown a number of causes for the diseased condition of the Fiji plants, reason exists for making 

 them known, as that information may be of assistance to the banana-growers in the northern part of 

 this Colony. 



The Fiji plants were found to be in some parts covered with aphides or plant lice, and these on 

 some of the plants were so numerous that they might have done considerable damage. Still, it could 

 not be proved from examination that they had done much damage, although they had existed in very 

 large numbers — as many as several hundred cast-off skins being often seen in the axil of one leaf. 



The Government entomologist, who has made an examination of these aphides, believes them to 

 be a new species ; drawings of them have been made by the departmental artist, and they will pro- 

 bably be described in a coming number of the Agricultural Gazette. In the root- stock of the Fiji 

 plants a fungus was found. What the exact nature of the fungus is has not yet been ascertained, be- 

 cause no spores could be found. The exact systematic position of the fungus therefore remains un- 

 known. But the fact that it docs a good deal of damage has been established. Its presence may be 

 known by a brown discolouration of the interior of the root-stock and roots.' The tissues instead of 

 being white, as they are when healthy, take on, where the fungus is thickest, a dark-brown tint, and 

 where it is just penetrating and has not yet caused a serious destruction of tissues, a light-brown 

 colour. 



It is rather remarkable that in the soil about the roots of these plants nearly thirty species of 

 shown to be injurious to tie pian^ on^them attacking the roo^and bling LdEr^ 

 h& cavities and the other being%und between the fheaths of thf feaves of 



Lwff Tf -n Tk f eca f 8e ™\ a t the very core where the tissues appeared to bs quite sound and 

 plants 4 1 £C f ° re f 8 IT that f thGre Sre f ° Ur 8G P arate Causea diseased condition of these 



nematodes ' P P ' a fUD8U8 CaUSiQg r0t in the root - st ° ck > ™* two different species of 



plete T LVth m e8e i :l that ™ SUgg68ted in the P reseut state of our knowledge, which of coursa is incom- 



aarv fr>r +v> „t +u i. f , . ^uuioo ciuauaieu oi me elements neces- 



sary tor the growth of the banana plants and therefore after a series of yeare the plants become weaklv 

 and do not thrive as at first Furthermore, and this is quite as important as the fir t reason TthI 

 banana plant or any other plant for that matter is grown continuously cn the same W for a Ion! 

 wh Th tir 8 ' ^ dl8ea8e . 8 °* the Pi*?* "o bound to accumulate on that piece b fhnd Tfi disea-f 

 which first appears m a mud form and only here and there, will in each succeeding year attack more 

 and more plants and usually ,n a more virulent manner. Unless special precautions^ take fc prevent 

 disease, a continuous and successful growth of any one plant on the sameknd is next to anlSi 

 i;; me i T thG ^P^ment thoroughly realises the difficulty of getting agriculturists ir a new 



uZ Z£ # " 7K Stem ?i r i 0ta V° n - 1 What furm ° r8 USUa11 ^ do 18 t0 find ™* th g e crop that will pay 

 them best, to learn the methods of cultivating it and to obtain the necessary machinery for that crop 7 



SSnJ Si. hTlV? 1 P 0Q m tUat , 8imp L e . Une 08 l0Qg aS P° 88ible " No one can blame them S 

 doing this, but a time always comes when this keeping to one crop can no longer be done and the 

 tendency is always to wait too long before beginning a system of rotation. * ' 



Z. Judging irom the specimens sent, the soil about banana plants is infested to an extraordinary 

 degree with nematodes, therefore it is best in cultivating, to plough deeply or to oc^srionaUv anb* 

 soil the land These nematodes attack the roots of plants and eL firgd^f^^iKrfSt 

 surface. As they become rarer as the depth of the soil increases, it follows that if the 1 and be ploughed 



tes w?n kTSffirJSJ: is tb0 *f rr tly bottora side up ' a soil —f«** £• 5™ 



toucs will be bi ought to the surface and at the same time the nematodes which were near the surface 

 are buried so deep that they can do much less damage than they could if at the surface 

 t, iJ'J/T 7V! ?* GU thU8 fur See "' the niaiu difficulty with these plants is thought to be due 

 ettia Z l°l ° I"" 8118 men . t,oued . abo ^ ™ d kM* the best remedy to recommend is |reat ca e in 

 Betting the new suckers, i. e., m making new plantations. As pointed out, the presence of fungua 



