102 FERTILIZERS 



gives several times as much fruit as an unfertilized block, the 

 two having been treated in exactly the same way except in the 

 matter of fertilizers, it is difficult to avoid drawing- the conclu- 

 sion that the fertilizer is responsible for the difference. In the 

 orchard fertilizer experiments at the Massachusetts Agricultural 

 Experiment Station (with which experiments the writer has had 

 no connection) the thing which most impresses any one who 

 studies the results and examines the trees, is the extremely poor 

 showing made by the trees which had no fertilizer. We may 

 disagree decidedly as to the relative merits of muriate and sul- 

 f ate of potash, or as to whether bone meal is best as a source of 

 phosphoric acid, but none can escape the conclusion that under 

 the conditions of this experiment any fertilizer combination used 

 was greatly to be preferred to no fertilizer at all. 



Influence of Nitrogen. With so much difference in opinion 

 as to what forms of fertilizer, if any, are required, it is hardly 

 to be expected that there should be very general agreement as to 

 the particular effect of the different fertilizer elements, yet all 

 are agreed that nitrogen, in any form, is likely to produce rapid 

 wood growth with large, dark green leaves and long terminal 

 shoots. If the application of nitrogen is carried to excess, the 

 wood growth is often made at the expense of fruit, though up to 

 a certain point nitrogen is apt to increase the yield. It almost 

 always decreases color, principally because the fruit, like the 

 leaves, is large in size and does not reach maturity until late in 

 the season. The heavy foliage also reduces the color by shutting 

 off the sunlight. 



Influence of Potash. It is known that potash enters into 

 the fruit acids and is a very large part (more than 50 per cent) 

 of the ash of fruits. Potash has also been credited, and rightly 

 so, with increasing the color in fruits. This effect is probably 

 produced by the influence which potash has on the general 

 growth of the tree. In any event fairly liberal applications of 

 some form of potash are generally made to bearing orchards if 

 the owner believes in fertilizing. 



Influence of Phosphoric Acid. The exact part which phos- 

 phoric acid plays in orchard development seems not to have been 



