30 



element for the production of superior fruit, The fine, smooth-- 

 skinned, and deliciously flavoured Indian and Halifax River 

 oranges, with their characteristic aroma, are grown largely on 

 soils rich in lime from shell mounds, and coralline, and coquina 

 rock. The oranges produced in the noted Orange Bend Ham^ 

 mock, which are of distinctive quality, with delicate, rich 

 aroma, and thin, smooth rind, are produced on a soil underlaid 

 by a marl rich in lime. Lime soils are in many orange 

 countries considered superior for orange growing. Dr. A. 

 Stutzer, in his work on the Fertilisation of Tropical Cultivated 

 Plants, Avrites; "The orange and citron fruits desire a deep, 

 porous, dry soil, rich in lime. If sufficient lime is not present 

 the fruit w 11 be thick-skinned, and not have a fine aroma." It 

 appears also that the effect of abundant lime is to hasten 

 to some extent the time of ripening. Fruits grown on 

 soils rich in lime appear to colour and become suitable for ship- 

 ping somewhat earlier than those grown on soils containing 

 but little lime. To secure a good quality of fruit the regular 

 application of lime may be found very desirable in may groves. 



Fertilisation as affecting disease. 



Probably the most common cause of injury to orange trees 

 is a lack of fertilisation, yet it is not frequent for disease to be 

 induced -or aggravated by excessive or improper fertilisation. 

 This may, indeed, be of much more importance than we are at 

 present inclined to believe. One of the forms of Die-back, a 

 common and destructive disease of the orange, is quite evidently 

 due to errors in fertilisation. In other cases the disease ap- 

 pears to be caused by planting in inproper soil. 



Die-Back. 



Die-back manifests itself by a number of striking characters. 

 The foliage becomes very dark green, the vigorous growth 

 remains angular and immature and frequently becomes strongly 

 recurved, and the tips turn up slightly, forming S-shaped 

 curves. In the spring, trees affected with this disease start out 

 a very vigorous growth, which may continue for several months. 

 Finally a reddish brown resinous substance exudes on the 

 twigs forming the so-called die-back stain, which is very 

 characteristic, and they begin to die back. This death of 

 tissues may include the entire new growth or only a portion 

 of it. Under the bark of the young limbs gum pockets form 

 and burst out, causing large, unsightly eruptions on the twigs. 

 Larger gum pockets frequently form at the nodes, producing 

 large swellings. If a tree is badly affected, no fruit is formed ; 

 if moderately affected an abundance of fruit sets, but the larger 

 portion of this turns to a lemon-yellow colour before half 



