538u 
may also have had a bad effect on them; for soon after removing the inclosure and 
manure they commenced gradually to improve, and are now nearly restored. 
A yery common error of beginners in orange-culture consists in burying the tree too 
deeply in the ground, covering up from 4 to8 inches of the collar of the stock, which should 
be above ground. In this condition the tree may live, but will grow very slowly, making 
very little new wood for years. When the buried collar has thrown out artificial roots 
the trees may revive, and in the mean time will continue to throw out vigorous sprouts, 
but they will die back each season, much to the disappointment of the impatient 
cultivator. This is termed “damping off.” When this is the case it is easily remedied 
by lifting the tree, or by bringing the natural roots to the surface. Drainage is all- 
important for orange-trees. They will not flourish when the roots remain in stagnant 
water. 
The disease known as the rust has affected the orange-trees since 1864 in this section 
of the State, the consideration of which is of far more importance than the black 
substance, &c., on the trees alluded to. The “rust” may be caused by an insect or a 
fungus. 
I will send you some samples of the oranges having dark stains, and also a few hay- 
ing clear skins, taken from the same tree, hoping that some of your scientists may be 
able to inform me what are the causes of the respective diseases, and, if possible, to 
suggest to me a remedy. 
Respectfully, your obedient servant, 
F. L. DARCY. 
Mr. J. A. Whitner, of Mellonville, Fla., states that “the rust appears 
either on high or low lands, more frequently on the low or flat lands, which 
in this locality are imperfectly drained. The trees affected with this dis- 
ease are always checked in growth, but rarely die. They recover under 
high cultivation with judicious manuring, but bear small and imperfect . 
fruit, with a tough, spotted rind, and a hard, insipid pulp. I send you, 
as requested, by this mail, specimens of twigs affected by this fungus, 
healthy and unhealthy, taken from the same tree; also specimens in- 
jured by bark-lice. These insects are very destructive and widely 
spread in this vicinity. They are the cause of the fungi or leaf smut 
generally confined to young trees.” 
The Department has received several communications from orange- 
tree cultivators of Texas in relation to orange blight, but thus far it 
J . . . 
would seem that the rust blight is unknown to them, as the following 
from Mr. Sidney Scudder, mayor of Galveston, Texas, will show: 
Your communication of November 27, 1872, was duly received. Careful inquiry 
of orange-tree growers and personal examinations of numbers of trees in this county 
have developed nothing in the shape of disease among them at this time. The exces- 
_ sive drought of the past summer diminished the crop considerably and caused the 
fruit to become unusually sour and unpalatable. This was, however, effectually reme- 
died by loosening the earth under the trees and spreading ashes or pulverized soil, or 
charcoal around them. The Rey. P. C. Tucker was particularly successful with this 
remedy applied to his orange-trees this fall. 
On being supplied with specimens of the so-called “ rust,” blackened 
leaves, branches, and fruit, I made a series of observations and experi- 
ments to ascertain, if possible, the character of the various phases of 
the fungus and affected parts, of the plant, so as to be able to point out 
cause and effect. I removed portions of the rust from the branches, sub- 
jected them to a power of about 30 diameters, and viewed them by 
reflected light. No fungoid forms were visible. 
I next treated a portion of the rust with caustic potash, in which the 
so-called rust proved partially soluble. The insoluble portions were 
washed with pure water until all soluble substances were removed. I 
then subjected several portions of the insoluble parts to a power of about 
100 diameters, when they were seen to consist of cellular, fibrous, and 
woody matters, and were wholly free from fungoid forms. I next sub- 
jected a portion of the “rust” to the action of alcohol of 95 per cent. 
proof. The alcohol became tinged of a brown color. On pouring a 
portion of the liquid into water a white precipitate was formed, showing 
the presence of a resin. 
° 
