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B. — DISEASES OR INJURIES IN PLANTS. 

 Smut in Corn. 



A cob of corn has been received from near Malvern, St. Elizabeth, covered with what has the ap- 

 pearance of soot. This disease is well known to the English farmer, and is called "smut." The soot- 

 like dust consists of immense numbers of minute " seeds" (spores) of a fungus (Ustilago earbo ). In 

 England it attacks wheat and several grasses besides. 



Smut is spread from place to place in two ways. First, it is so light that every breath of wind 

 carries some of it away to settle and grow in fresh soil. Secondly, some grains of smut, so few per- 

 haps as not to be seen, adhere to corn which is used as seed, and therefore the disease is propagated 

 together with the corn. It germinates in the soil, and gradually grows up through the plants which 

 it attacks. 



To kill the smut, and at the same time prevent it from being spread by the wind every plant of 

 corn, every grass, which shows any sign of it, should be at once picked and burnt. It is of no use deal- 

 ing with the corn alone, for if infected grass is left it acts as a nurse for the smut, from which it 

 spreads to corn. Laborers in the field, settlers, in fact everyone, can do a service to the country by 

 dealing with the disease in this way at once as soon as it is perceived. 



Those who sow corn must adopt some method for killing the smut on the seed-corn, if they have 

 any reason to think that the corn is infected. The simplest plan to adopt is as follows : — Dissolve one 

 pound of bluestone in 5 quarts of boiling water. This is sufficient for 4 bushels. When cool soak the 

 corn for 10 minutes. The seed may then be sown with every probability that the smut has been 

 effectually killed. 



Disease in Orange Trees. 



Last May the following prescription was given to be used for Orange trees which had begun to die 

 off. The bark was decaying at the collar, and from the original starting point the decay was spreading 

 and in some cases had completely encircled the stem. The leaves had begun to turn yellow, and there 

 is no doubt that the whole plantation was doomed, unless the remedy proved effectual : — 



Apply to the wounds in the bark a mixture composed as follows : — 2 lbs. stiff clay, 2 lbs. flowers 

 of sulphur, ^ lb. soft soap, 1 tablespoonful kerosene oil, mix with water to consistency of paint and 

 apply with a brush. The oil should be added last, and the mixture should be allowed to stand 12 

 hours before being used. 



It is satisfactory to have received the following statement, dated 2nd September : — 



" After having applied on two different occasions — at an interval of 10 days — the preparation you 

 were good enough to prescribe for my Orange trees — the disease — whether fungoid or animal which 

 attacked them at the end of the stem just where it touches the earth — completely disappeared. The 

 trees whose peel had been eaten away all round the stem have died but wherever there remained a 

 strip of peel to connect with the peel on the roots the tree has recovered after lingering more or less 

 according to the injury it had sustained prior to the application of your prescription. 



There is no appearance of the disease at present on any of the trees and the peel newly formed 

 is covering over that part of the stem which the disease had eaten away. 



It seems to be rather singular that all the trees of a plantation numbering over 200 were attacked 

 simultaneously by this disease and that they were mostly young trees though a few old trees in the 

 immediate neighbourhood suffered equally." (Signed) Oscar Marescaux. 



Cinchona. 



Some Cinchona trees have lately been dying off. On investigation, it was found that the bark at 

 the junction of stem and root had been injured, and that in consequence the mycelium of a fungus had 

 penetrated between the bark and wood. The bark had become loosened on the roots, and decayed away. 

 It is probable that the injury was caused by the wind during the last hurricane. It would be difficult 

 to detect such injury at first, but probably an early application of the remedy prescribed above for the 

 Orange trees would have saved the trees. Trees which are too far gone to save should be taken up 

 by the roots, and barked. The bark may be stored, after thorough drying, for mildew does not affect 

 the quantity or quality of the alkaloids, when once the bark is cured. 



Coffee culture in Rio Janeiro. 



Reporting on the general state of the province of Rio Janeiro, the British Consul thus speaks of 



the coffee : 



In the districts of Cantagallo, S. Fidelis, and other parts, for some years past, the coffee trees have 

 been subject to a disease manifested firstly in the yellowness of the upper leaves, and afterwards in the 

 shoots, the trees soon drying up. In this way about one-tenth part of the trees in the above named 

 districts have perished. This disease is supposed to be propagated by an insect which lives in, and 

 feeds on the roots. It deposits its eggs in the knots of the roots causing the fibres of the same to rot. 

 On t liia the eggs are seen, having the shape of mushrooms. This generally takes place in the heaps of 

 weeds or grass which rot at the foot of the trees, forming a fine soil for the new root fibres. As a 

 remedy against this evil it is recommended by Dr. Glaziou that the weeds and grass should never be 

 heaped up to rot near the roots, but should be left to be dried by the sun and afterwards brought to- 

 gether and burned. The Orange tree3 are also subject to be attacked by the same plague. Dr. Glaziou 

 is convinced if this rule be attended to that in two years' time the coffee estates will return to what 

 they were formerly. — Gardeners Chronicle. 



