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fungal mycelium left in the soil. As pointed out previously, a 

 good deal of this can be destroyed by exposure to the action of 

 the sun but it can also be destroyed, to a large extent, by the use 

 of lime. The lime should be, if possible, unslaked, as in this state 

 its fungicidal powers are far greater than when it is slaked. It 

 should be applied before forking or ploughing and the amount to 

 be used must depend upon local conditions, and upon the extent 

 of the disease. 



A method of preventing death of forest trees, etc., from root 

 diseases in France is to lay bare the base of the trunk and as 

 many roots as possible and to apply quantities of sulphur or 

 ferrous sulphate. An experiment was tried with the application 

 of a 3 per cent, solution of carbolic acid to the roots of several 

 diseased trees at Cedros but, so far, information respecting this 

 treatment has not yet come to hand. 



The spraying of diseased trees with Bordeaux mixture may also 

 prove beneficial in destroying spores of the fungus and applica- 

 tions to surrounding trees might prevent them from becoming 

 infected by spores blown by the wind. 



5-— IMPROVED CULTIVATION AND DRAINAGE. 



It has been noticed that the disease is the more destructive in 

 undrained land. Stagnant water should not be allowed to remain 

 in the soil, as this tends to hinder healthy root development and 

 also favours the spread of the fungus. It would appear that water 

 may be present at the roots of the coco-nut to almost any extent, 

 but the necessary condition is that it should not be stationary. 

 Proper drainage not only relieves the soil of excess of water, but 

 also allows greater root development to take place, and thus 

 secures the plant against effects of drought. 



The cultivation of land under coco-nuts is, as a rule, neglected 

 and instances have been noticed where old plantations have been 

 giving smaller yields of nuts that have been gradually diminish- 

 ing in size, year after year. Better cultivation and drainage would 

 offer more favourable opportunities for the coco-nut, and would 

 probably be of considerable value in dealing with the root disease 

 especially in wet areas with soil of a clayey nature. It would 

 afford a better chance for the plant to make use of plant food, 

 either from the soil or from manures (the evidence of a planter in 

 the Cedros district, which shows returns of 120,000 nuts per year 

 from an area that gave 40,000 nuts per year five years previously 

 through judicious applications of manures, emphasizes the fact 

 that the coco-nut readily responds, in some soils at least, to liberal 

 applications of manures.) It also would be expected that the con- 

 dition of the trees would be considerably improved. By encou- 

 raging healthy growth and increasing the vigour of the trees, they 

 will be able better to withstand the attack of the fungus. 



6.— SEARCHING FOR AND PROPAGATING DISEASE-RESISTANT 



VARIETIES. 

 A good deal of work has been done in combating plant diseases 



