Winter Meeting. 



393 



Moreover, in seasons of extensive wood growth, the leaf growth is 

 also larger than when a tree is carrying fruit, and for the development 

 of the leaf crop there is required about the same amount of plant food 

 as for the normal fruit crop. In fact, to produce the leaves requires 

 nearly double the amount of nitrogen that is used by the fruit, and ten 

 times as much lime, although only about half as much potash and 

 phosphoric acid. 



The New York Experiment Station* has in a recent bulletin given 

 us some very interesting and valuable data on this point that will serve 

 as a general guide, and are fully set forth in the following table : 



AMOUNTS OF PLANT FOOD USED PER ACRE. 



Variety. 



Numberof 



trees per 



acre. 



Nitrogen 

 lbs. 



Phos. acid 



(P205) 



lbs. 



Potash 



(K30) 

 lbs. 



Lime 



(UaO) 



lbs. 



Magnesia 



(MgO) 



lbs. 



Apple. 

 Peach. 

 Pear... 



Plum . 



23.0 

 35.0 

 11.0 

 13.0 



The plant food in the above table represents that required for the 

 building of all the new v/ood growth, for what was deemed to be 

 a normal fruit crop, and for the leaves, from representative trees in 

 the full vigor of bearing. 



"The fruit, leaves, and the new wood, as represented by the tips 

 of the branches, were carefully gathered, weighed, dried and analyzed. 

 Precautions were taken when necessary to avoid the loss of foliage by 

 enclosing the entire tree in mosquito netting. A record was kept of the 

 fruit that fell before the final picking. The fruit was picked at the 

 stage of ripeness usual in common practice. The foliage was left until 

 it showed a tendency to drop. The twigs of new wood were removed 

 soon afterwards."* 



It will be noted that in the above estimate only 35 apple trees arc 

 computed per acre, while it is customary in Missouri to set 70. The 

 amounts of plant food used per acre should not, however, be doubled to 

 make the data apply to our conditions, for the reason that these were 

 larger trees than we grow and perhaps as fully occupied the ground 

 as our 70 trees would under normal conditions. This being true, it 

 is likely that as nnich plant food was required as would be needed for 

 an acre of trees planted in our way, and in my judgment, the figures 

 as given are high enough for our conditions. The number of trees 

 grown per acre of the other sorts is essentially the same as grown by us. 



*New York Exp. Station Bulletin No. 365. 



