STATE POMOLOGICAL SOCIETY. 57 



furnish all these materials indefinite!) in the amounts and 

 times required, and, unless proper assistance is rendered 

 there must come a time when production is materially reduced 

 and off seasons occur. 



On the other hand, it may be noted that part of the orchard's 

 product requires comparatively small amounts of the impor- 

 tant elements. This is especially true of the wood, even when 

 the annual production of mature trees is considered. Inci- 

 dentally this accounts for the fact that young trees are much 

 less likely to make a profitable response to fertilizer applica- 

 tions than those of bearing age. Such trees often respond ver> 

 well to manure or to any other satisfactory mulch, as shown in 

 three of our experiments considered elsewhere. This, how- 

 ever, is apparently due more to moisture conservation than to 

 any direct increase in fertility. 



The large amount of lime contained in the wood may have 

 some significance, because, as shown later in several of our 

 experiments, its application has resulted in considerable im- 

 provement in growth. In the fruit, however, very little lime 

 is required, and hence its application should not be expected to 

 affect the yields materially, and this corresponds with our 

 field results. Moreover, the total effect of adding lime alone 

 is surprisingly small, in comparison with the large amounts 

 that are taken up. Either these amounts are merely drawn in 

 and deposited mechanically, and hence are largely without 

 physiological significance, or else the average soil is still able 

 to supply tne lime needed. 



With iron the case is very similar. This element is almost 

 universally present in agricultural soils and the total amount 

 required is so small that its addition can scarcely be expected 

 to produce any important eft'ect. This also is borne out by 

 such experimental results as are now available. 



The fruit, on the other hand, carries a large amount of 

 potash. From this, one might suppose that its addition to the 

 soil would be very important in improving yields, and this 

 idea has been widely proclaimed, especially by those considering 

 only the chemical composition of the fruit. As indicated later. 

 however, most orchard soils are already sufficiently supplied 



