611) THE FARMERS' HANDBOOK. 



Fiji Disease. 



Fiji disease shows itself in short, stunted growth with small, deformed, 

 wrinkled leaves, on some of which scorched patches occur. Later, the buds 

 on the stalks sprout and numerous small suckers spring from the ground. 



Peculiar galls are found on the underneath side of the leaves, in the form 

 of small, elongated lumps or ridges, both on the midribs and on the leaf- 

 blades. These galls provide the best means for diagnosing the disease, 

 especially as they may be found in its early stages while the cane appears 

 otherwise healthy, as well as in all later stages. 



Where it has gained a good hold, this disease has proved difficult te deal 

 with, because all varieties are attacked by it. Mahona and Badila have 

 proved to be rather more resistant than D 1135, N.G. If), and most of the 

 other varieties grown. 



Yellow Stripe Disease. 



This is also known as "Mottling' - or "Mosaic" disease. It is recognisable 

 by a peculiar mottling of the leaves, by which their green colouring is reduced 

 to a lighter, more yellowish tint. In the more advanced stages, similar 

 mottled markings may also be seen on the rind of the stalks. 



• These are the only evidences of disease to be found. Far from being 

 destroyed, affected canes appear to the casual observer to have nothing wrong 

 with them. Yet this disease causes severe losses of crop by reducing the 

 vigour of growth, producing thinner, shorter stalks, fewer stalks per stool 

 and generally a much lower weight per acre of cane. Further, its effects 

 are cumulative, becoming more and more severe with each successive planting 

 of diseased stock. 



Many cases of the so-called deterioration or "running out" of varieties 

 have undoubtedly been due to this disease. 



All of the present approved varieties are liable to its attack. Of these 

 N.G. 16 and Mahona appear most resistant, while Innis 131, Malabar, and 

 1900 Seedling are rather susceptible. 



Controlling these Diseases. 



As already stated, clean cultivation and the planting only of healthy cane 

 are the methods of control that the farmer should regard as most practical 

 and effective. These methods may be summarised thus : — 



1. Selection of healthy cane for planting. 



2. Eradication of disease in the young crops. 



3. Dealing with badly diseased ci-ops. 

 i. Avoidance of knife infection. 



5. Attention to drainage. 



1. Selection of Healthy Cane for Planting. — This is of hrst importance, 

 because, in the case of these four diseases, infected cuttings — if they grow 7 — 

 invariably produce diseased stools. 



It has been found that a portion of the cuttings may prove diseased when 

 they are taken from the healthy-looking stools in fields where disease is 

 present. This is especially the case with gumming, leaf-scald, and Fiji 

 disease. When healthy canes become infected by these diseases, they 

 undergo a prolonged period of incubation, varying from a few weeks to 

 tvelve months or more", before any decided symptoms appear. 



