HORTICULTURE. 



455 



and trees affected with ^mn diseaMe ami otherwise out of the iiornial, are given. As 

 a basis for ealculation the author gives the average analysis of the parts of the orange 

 tree, as determined l)y liiinseU", as follows: 



Andhfsi)^ of orange trees. 



On the at)ove basis, it is ealcuhited that a hectare of oranges containing al)0ut 250 

 trees and yielding, when in full ))earing, 30,000 kg. of fruit, would remove from the 

 soil 114 kg. of nitrogen, 120 kg. of phosphoric acid, and 114 kg. of potash. If these 

 elements are returned to the soil the ecjuivalent of 760 kg. of nitrate of soda, 705 kg. 

 of superphos})hate of lime, and 225 kg. of sulphate of jtotash will be required. This 

 fornnila is intended for soils composed mainly of siliceous sand with some lime and 

 clay, having a good depth, and capable during the summer of receiving copious irri- 

 gation. This is considered by the author the ideal soil for oranges. On other soils 

 this fornmla can not be strictly adhered to. 



The evil effects attributed to an excess of nitrogen are that it produces an exuberant 

 growth of wood and foliage, while the resulting fruit is very coarse and thick skinned, 

 with little sugar or aroma, and of bad keeping quality. The time of ripening is also 

 retarded. With an excess of phosphoric acid the fruits are small, numerous, well 

 flavored, and aromatic, with thin skins and poor pulp. "When potash is super- 

 abundant, the tree does not grow very large, but the fruit is juicy, sweet, and of 

 pleasant flavor." 



As to the most desirable forms of fertilizers, the author prefers sulphate of ammonia 

 in light soils and in those charged with organic matter; nitrate of soda is better 

 applied to heavy soils. Superphosphate of lime is considered the best of the phos- 

 phate fertilizers. "Only in gypseous soils and thoee humid and rich in organic 

 residues should the phosphate 'Thomas' be employed." The sulphate and chlorid 

 of potash may be used indifferently, though the sulphate appears to give more 

 delicacy and fragrance to the fruit. In rather limy soils the use of sulphate of iron 

 is considered beneficial. In those with a little lime, and especially if inclined to be 

 rough and clayey, the use of gyj)sum is advised. 



In fertilizing young trees materials furnishing about one-half the nitrogen and 

 phosphoric acid and one-fourth the potash required for an orchard in full bearing, 

 as noted above, are required. For old trees the following is one formula recommended : 

 Sulphate of anunonia, 300 kg. ; nitrate of soda, 400 kg.; superphosphate of lime and 

 manganese, 800 kg.; sulphate of iron, 300 kg.; chlorid of jjotassium, 25 kg., per 

 hectare. In the case of orange trees which produce an abundance of wood, leaf, and 

 flowers with but little fruit, the author believes the defect due either to a deficiency of 

 nutrition or to a deficiency of the pliosphates which promote the fecundation of the 

 ovary of the flower, or to a superabundance of nitrogen, "which by excessively 

 expanding the sexual organs of the flower produces its abortion." The following 

 formula is suggested for such trees: Sulphate of ammonia, 75 kg.; nitrate of soda, 

 75 kg.; superphosphate of lime, 1,000 kg.; kainit, 300 kg.; sulphate of lime, 300 kg., 

 per hectare. With orange trees suffering from gumming the use of organic fertilizers, 

 and especially horse manure, should l)e avoided. The only nianui'e re(]uired for trees 

 in the seed bed is the free use of horse manure. 



In orange fertilization the manures should be i)lowed under after the croj) is 

 gathered. If ai)j)lied later or at blossoming time, the sap rises hastily and the "gen- 



