28 [ CITRUS FRUITS 



soon after the first rains of autumn. Deep tillage or 

 trenching, usually associated with manuring is performed 

 every sixth or eighth year, the best time for this operation 

 being May or the early days of June, and is immediately 

 followed by the first watering, but is sometimes done in 

 autumn soon after the first rains, and before the soil 

 becomes too wet to be worked properly. 



Manuring without trenching may be done at any 

 time, but chiefly in autumn, when the circular trough 

 used for irrigation, is deepened, the manure evenly 

 distributed over the whole surface and the earth again 

 drawn in and levelled. The operation is repeated every 

 third or fourth year. When trenched the manure is given 

 at the rate of 48 m. tons per hectare (20-22 m. tons per 

 acre, of 25 viaggi per tumulo, Maltese measure), but when 

 supplied in the circular trough above mentioned, one bag 

 per tree, weighing on an average 50 kilog., will be 

 sufficient. Trenching is of course much more expensive, 

 but has the great advantage of tilling deeply and manur- 

 ing the whole area, and the trees are benefited in 

 proportion. Well-rotted manure from the cow-shed is 

 the best for red soils, and stable-manure well matured is 

 preferred for whitish and clayey soils. Young trees 

 recently transplanted are induced to make vigorous 

 growth by a supply of manure from the pig-sty. Chemical 

 fertilizers, as a complementary dressing, particularly 

 superphosphates may be given before commencing the 

 operation of trenching. Superphosphates may be distri- 

 buted on the surface of the land at the rate of 800 to 

 1 200 kilog. per hectare or 360 to 540 kilog. per acre, or 

 ioo to 150 kilog. per tumolo; or they may be strewn on 

 the surface when trenching is completed, before levelling 

 the heaps of soil. It is not advisable to give superphos- 

 phates in the trench, in direct contact with organic 

 manure. A dressing of superphosphates may be given 

 every second or third year, in the circular trough, before 

 commencing watering, at the rate of three to five kilog. 



