DISEASES OF THE ORANGE IN FLORIDA. 1 5 I 



muck, the decay of masses of roots in the ground 

 near the trees, are all frequent causes of die-back. 



Remedies, Prune the roots till all blackened 

 wood is cut off. Do not cultivate, but let the 

 ground grow in weeds or grass till the cause is re- 

 moved. The soil will be greatly improved by a 

 liberal application of lime. 



III. FOOT- ROT. 



(Gum disease, mal di goma). This disease has 

 long been known in Europe. The prominent symp- 

 toms are exudation of a gummy or sappy fluid 

 from near the base of the trunk, the decay of the 

 bark in that region and of the roots below. Be- 

 ginning at one or more points, the disease extends 

 in all directions till the tree is girdled. Sometimes 

 the exudation of diseased sap appears at various 

 places along the trunk. This disease, like most 

 others, is apt to attack trees enfeebled by age or 

 bad condition of the soil, etc. 



Causes. Rupture of bark admitting the atmos- 

 phere charged with germs of ferment. Piles of 

 litter at the base of the trunk would prove a favor- 

 able place for the development of such germs. 

 The disease is most prevalent after a freeze suffi- 

 cient to rupture the bark of the trunk. The de- 

 caying of fruit or other vegetable matter upon the 

 ground furnish the germs of the disease, while the 

 oxidation of the sap and the slow circulation re- 

 sulting from damage by the cold favor the condi- 



