Diseases of the Orange. 



Cultivation of 



The most serious diseases of the orange tree are those citrus Fruits 

 known as "gum disease" and "die-back". ~^ 



The treatment for the former is by the use of a wash of 

 lime, crude carbolic acid and salt. The sour orange stock 

 is said to be practically proof against gum disease. The 

 pomelo stock is also resistant to it. 



The application of organic manures, and in particular 

 of barn-yard manure, should be altogether avoided in the 

 case of trees suffering from gum sickness. 



With regard to "die-back" Dr. E. W. Hilgard writes: 

 "In almost all cases of "die-back," examination has shown some 

 fault in the sub-soil, which puts the roots under stress. Such fault may be 

 an underlying hardpan or impervious clay, pure and simple ; or it may be 

 excessive wetness or dryness of the sub-strata surrounding the deeper roots ; 

 or the rise of bottom water from below, as in cases of over-irrigation. The 

 true "die-back" is not properly a disease, but simply the manifestation of 

 the distress felt by the root-system underground. The first thing needful 

 is to dig down and examine the roots, and then to relieve whatever fault 

 may be found, if possible ; which may not always be the case. Sometimes 

 an appearance similar to the "die-back" is caused by the roots encountering 

 a marly stratum, which is apt to stunt the growth of the tree, causing it to 

 put out a multitude of small, thin branches, and sometimes causing the tips 

 to die off. For this form of the trouble there is no permanent remedy ; the 

 trees should never have been planted in such ground, any more than in such 

 as has shallow-lying hardpan or clay." 



Pomelos. 



As a tree, the pomelo most nearly resembles the orange, 

 and its culture is virtually the same. It is a rapid grower 

 and precocious in fruit-bearing. Like all citrus fruits, the 

 weight and quality of its yields are to a very great extent 

 a reflection of the care and food given to the tree. It may 

 be stated as an indisputable fact that the grower who fertil- 

 izes heavily has the largest crop, the best fruit, and the 

 largest profit from his plantation. 



To attain the standard of excellence the fruit must have 

 the characteristic pomelo flavour a pleasant commingling 

 of bitterness, sweetness and acidity. Among the large 

 varieties, Duncan, Hall, McKinley, Pernambuco, Standard 

 and Walters are prominent. Triumph is a good variety, 

 as well as the Marsh, the latter being notable for the small 

 number of its seeds. Of the smaller varieties Josselyn is 

 probably the most characteristic. 



