140 The Principles of Fruit-growing 



kind of fertilizer applications, though potash and possibly phos- 

 phates may be of some slight assistance. These colors are directly 

 dependent upon sunlight and maturity, with the latter occurring 

 preferably on the tree. Late picking, open pruning, light soils, sod 

 culture and mildly injurious sprays, therefore, tend to increase the 

 reds in fruits, while opposite conditions decrease them. 



"The retarding influence of nitrogenous fertilizers or manure on 

 color makes it advisable to use them less freely on some of the red 

 varieties, especially those in which the color comes on rather tardily, 

 such as the York Imperial. On the lighter soils, or in localities with 

 the longer growing seasons, this precaution is less important. 



"It has been noted that the fertilizing elements found effective 

 in certain experiments were not so in others. In one of our experi- 

 ments, no form of fertilization has yet shown a profitable response, 

 and in two others such responses have come only from manure and 

 mulches. It is evident therefore that the actual fertilization of a 

 given orchard is still largely a local problem. 



"It is possible, however, to indicate the more prominent char- 

 acteristics of orchards that are in need of fertilization, and to form- 

 ulate a general fertilizer, based on present experimental results, that 

 may be used in such orchards until more definite local data can be 

 secured. (See page 143.) 



"Present evidence indicates that the nitrates, or other specially 

 soluble plant-foods, are best applied somewhat after the fruit has 

 set. In addition to greater effectiveness, this delay enables the 

 rate of application to be varied somewhat in accord with the amount 

 of fruit set, making the applications heavier when the crop is heavy 

 and vice versa. In the long run, this plan should steady the yields and 

 get maximum benefits from the fertilization applied." 



What to do. 



There is every reason to expect, from the nature of the 

 case, that orchards profit by liberal fertilizing. Whether 

 added plant-food is needed under every set of conditions 

 is quite another matter, and it is a problem that must be 

 answered by tests made on the place. Whether special 

 treatments are needed in fruit-plantations to correct 

 toxicity of the soil, or to accomplish other results, is also 



