CITRUS FRUITS ] 29 



per tree. Superphosphates are useful to provoke 

 vigorous growth, particularly after a severe attack of 

 scale, and materially assist in obtaining a better crop. 



Chloride of potassium (kaintt) or wood ashes are 

 useful for sandy soils, and are best supplied late in 

 spring before watering. They may be given at the rate 

 of one or two kilog. per tree in the case of kainit, and of 

 three to five kilog. in the case of wood-ashes. Nitrogenous 

 fertilizers, (nitrate of soda and sulphate of ammonia), may 

 be used whenever organic manure is not available, but 

 as a rule Citrus trees are not much benefited by nitrogen- 

 ous fertilizers, except when they are young. It would 

 be certainly cheaper, and perhaps better, to resort to 

 green-manuring, making use of some leguminous plant, 

 such as the vetches, or the lucernes, which may be sown 

 broadcast when the land is first weeded and digged in 

 November or December, and the plants are digged in 

 when they are in flower, in April. This operation repeat- 

 ed every second year will enrich the soil in nitrogen, and 

 also in humus or organic matter resulting from the decay 

 of vegetation. 



PRUNING. All Citrus trees are pruned every second 

 or third year, and the operation can be done at any time 

 of the year, the best period being from May to September. 

 The essentials for good pruning are ' (a) the removal of 

 all dead wood, and sickly growth, (b) the removal of 

 superfluous growth within the tree and also on the 

 outside, (c) the disposing of the main branches to the 

 required shape when the tree is young, and keeping the 

 tree to the required shape, when adult. Careful gardeners 

 trim their trees every year between one pruning and 

 another, in order to remove all dead twigs, and to put 

 down superfluous growth which may injure the bearing 

 capacity of the tree. In fact it is known that most 

 Citrus trees, particularly the orange, have a tendency to 

 produce several shoots close together at the end of the 

 twig, and the resulting distribution of energy provokes a 



