STATE POMOLOGICAL SOCIETY. 6/ 



Potash, on the other hand, in direct contrast to its effect in 

 the experiment above, here shows a distinct gain in yield wher- 

 ever it is applied. The best of these gains — the one in com- 

 bination with nitrogen — is only 68.4 bushels per acre annu- 

 ally, but this is more than 40 per cent increase over the normal 

 yield, and it shows a fair profit over the cost of treatment, 

 besides giving over 17 per cent of an increase in growth. Pot- 

 ash apphcations, therefore,* have evidently been of value in this 

 orchard, even when those of manure and of nitrogen and 

 phosphates were largely failing. 



The Action of Manure vs. that of Commercial Fertiliser. — 

 The above facts, taken in connection with those shown in the 

 two earlier experiments, indicate that the plant-food action of 

 manure is practically identical with that of a commercial fer- 

 tilizer rich in nitrogen and phosphates. It also apparently in- 

 dicates that the potash in the manure may be less readily 

 available than that carried in commercial forms. The old con- 

 troversy over the relative value of manure and commercial fer- 

 tilizers, therefore, is without any particular significance, so far 

 as plant food is concerned. Either type of fertilizer may be 

 successful or either may be a failure, depending upon the par- 

 ticular conditions involved. 



The manure, however, often has some additional value as a 

 mulch. This naturally can not be duplicated by commercial 

 fertilizers alone, though it may be duplicated by any other kind 

 of mulch, as has been shown especially in our experiment in 

 the Mynard orchard in Bradford county, and also in most 

 of our cultural method experiments. The matter of availabil- 

 ity also is often important, as manure cannot always be se- 

 cured, and it is for this reason that the relation between ma- 

 nure and nitrogenous fertilizers should be well understood. 

 Moreover, it sometimes happens that large and regular appli- 

 cations of manure may result in a distinct increase in the 

 amount of blight, and also in an undue increase in the size of 

 the fruit and in the amount of punky pitting in the flesh of the 

 latter. In such cases, a reduction in the applications or the 

 partial or complete substitution of a proper commercial fer- 

 tilizer is desirable. 



