28 
conical pustules, from 2 to 3 mm.in diameter. At first these are white 
or orange yellow throughout, but in the mature stage the spore masses 
become orange red (Pl. VII, fig. 2). This fungus is frequently found in ~ 
groves affected with sooty mold. It dots the under surfaces of the 
leaves, and may occasion alarm if its nature is not understood. Unless 
examined in an early stage of development, no trace of the mealy-wing 
scale can be discovered without microscopic study. 
When sooty mold follows attacks of the wax scale, mealy bug, or — 
orange aphis, thorough sprayings with the resin wash or standard kero- 
sene emulsion will be found effective. The time when the treatment 
should be made is not important in these cases, but if the resin wash 
is used a dry season should be selected, when the work will not be 
rendered uncertain by the liability of rainfall. 
FOOT ROT! OR MAL-DI-GOMMA. 
Foot rot or mal-di-gomma is a disease chiefly of the orange and lemon, 
and is probably more widespread than any other citrous malady. It is 
known to occur in almost all countries where the orange is cultivated, 
but so far as known appeared first in the Azores Islands, where it was 
very severe. According to the statement of Fouque,? it was first 
noticed in this group in 1834, on the island of San Miguel, where it 
seems to have originated. From that time until 1840 he estimates that 
fully one-fourth of the trees were destroyed. It reached its greatest 
severity on the island in 1840; in 1842 it began to decrease, and in 1873 
it had ceased to be very serious. F. Alphonso® says that according to 
general report the malady appeared in Portugal in 1845, in Hyeres in 
1851,‘ in Lago di Garda in 1855, and in Messina in 1863. According to 
Briosi® the disease first appeared in Sicily in 1862, and afterwards 
spread to Naples, Liguria, and Lago di Garda, everywhere destroying 
orange and lemon trees by thousands. Professor Wohler (mentioned 
in Briosi’s monograph referred to in foot-note) found the malady very 
destructive on the Balearic Islands in 1871. Statements differ in 
regard to the first appearance of the disease in Florida, but it seems to 
have been noted here some eighteen or twenty years ago. Dr. A. H. 
Curtis® says: ‘‘It appeared about nineteen years ago, though few 
1 An account of this disease, prepared by B. T. Galloway, was published in Part IT 
of Bulletin No. 8 of the Division of Botany, U. 8. Department of Agriculture. 
2 Voyages geologiques aux Acores, III, Les Cultures de 8. Miguel (Revue des deux 
Mondes, Paris, Apr. 15, 1873, p. 837). 
‘Alphonso, F., La coltivazione degli aranci nelle Azzorre (Annali di agricoltura 
Siciliana, Vol. v, 1873, p. 311). 
‘Rendu, M. V., Note sur la maladie des oranges d’Hyéres, Proeee (Commission- 
aires Jussieu, Gaudichaud’ Decasne) (Compt. Rend., t. 33, 1851, pp. 681-683). 
‘Briosi, Giovanni, Intorno al mal di gomma degli agrumi (Fusisporium limoni, 
Briosi) (Atti della R. Acad. dei Lincei, Roma, ser. 3°, Vol. Ii; Memoria. delia classe 
di science fisiche ecc, meeting of May 5, 1878, pp. 485-496). 
®Curtis, A, H,, Sore shin or gum disease (Fla, Expt, Sta. Bull. No. 2, June, 1888, 
pp. 29-35). 
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