638 THE ORANGE. 



to be no specific remedy, but trees showing these symptoms 

 have, in some instances, been fully restored by digging a 

 trench all round two or three feet from the trunk, filling in 

 with fresh soil mixed with manure, and pruning away nearly 

 all the top. Doubtless some cases of limb-blight are the re- 

 sult of overcropping, and exhaustion of necessary elements. 

 It seems to affect adjacent trees, but whether contagious has 

 not yet been definitely settled. Removal and burning of 

 affected limbs and extirpation of badly diseased trees are 

 recommended, but as some forms of blight may proceed from 

 preventable causes it might be well to go slowly in the execu- 

 tion of such heroic measures. The matter is being studied 

 by experts and will be better understood after further investi- 

 gation. 



Dieback. Another trouble of the grower, and perhaps the 

 most common, is a condition called " dieback." This may be 

 recognized by the damping-off of the ends of growing shoots, 

 which are often unduly angular, distorted, curving downward, 

 fairly bursting with crude sap, and disfigured by rusty red 

 patches of exuding gum. There is a mighty effort at rapid 

 growth ; a constant advance and retrogression. Bearing trees 

 either produce no fruit, or else set a heavy crop, which as- 

 sumes a whity-green color, becomes scabby, cracks open and 

 drops, and any that reaches maturity is insipid and worth- 

 less. It must be considered a condition rather than a disease, 

 a dyspeptic state arising from over-stimulation or one-sided 

 fertilizers. It is also caused by too deep planting, a wet and 

 steaming soil, one that holds some noxious element, or is un- 

 derlaid near the surface with impervious rock or hardpan. 

 The grower must form a diagnosis of his own peculiar case, in 

 order to know what remedy to apply or what cause to remove. 

 If trees have been planted too deep they must be raised ; sod- 

 den soils may have shallow cultivation, or top shade, or lie in 

 grass during the hot and rainy season; fermenting and over- 

 stimulating fertilizers must be avoided and noxious elements 

 neutralized. On a soil naturally adapted to the orange and 

 judiciously fertilized and cultivated dieback is unknown. 



The same causes, variously affecting other plants, have been 

 noticed. Pear and apple trees by a poultry-house or manure- 

 pile have been killed outright; banana-plants have grown 



