166 PLANT PRODUCTS 



in the cake. An acre of land produces about 60 bundles 

 of indigo plants, each about five feet in girth, which yield 

 about ten pounds of indigo cake. Different parts of the 

 plant yield different quantities of indigo, the upper parts 

 of the plant being most prolific. About one-half per cent, 

 of crude indigo is obtained, representing about J per cent, of 

 real indigotin. The actual manufacture usually commences 

 about the middle of June, which is a compromise, as the 

 greatest percentage of indigotin does not correspond with the 

 greatest yield of crop. New varieties are also being intro- 

 duced, which are said to be able to yield as much as 

 twenty -five pounds of crude indigo per acre. The processes 

 of dyeing are described by Knecht (see p. 168). 



Fruit Products. Fruit farming is practised on a very 

 large scale in America, where considerable areas of special 

 land are covered with only one or two species. In Europe 

 generally more variety is displayed. In Great Britain 

 fruit growing is chiefly of the market garden type, although 

 on the continent of Bui ope considerable quantities of fruit are 

 grown on communistic lines in the villages and small towns. 



The manuring of fruit trees cannot be placed on the 

 same basis as the fertilizing of other crops. Newly planted 

 trees should on no account receive large applications of 

 concentrated chemical manure, and the manuring of 

 established trees must be considered individually. The great 

 point of variation in the requirements of fruit trees is that 

 of the supply of nitrogen ; on the other hand, phosphates 

 are always needed. Many trees are inclined to run to wood, 

 whilst others become stunted from bearing too heavy crops. 

 Old or unhealthy trees receive much benefit fiom nitrogenous 

 fertilizers. Grazing by poultry, etc., in the orchard is also 

 useful. Apple trees are especially benefited by phosphates ; 

 a dressing of basic slag in the autumn, followed by a small 

 dressing of super-phosphate in the spring is a very excellent 

 method of procedure. Kainit makes a very good source 

 of potash for trees that are growing on light soils, whilst 

 many growers apply nitrate of soda, before the flowering 

 time. The preservation of fruit may be conducted either 



