Fertilizers for Apples 139 



value in aiding growth. In addition, it may have some indirect 

 value in facilitating the growth of leguminous intercrops, and also 

 in correcting a possible toxic action possessed by the basic radicals 

 of a number of salts, some of which are present in commercial 

 nutrients. 



"At present, the high-grade sulphate in om: experiments is show- 

 ing no superiority over the muriate as a carrier of potash, but the 

 reverse is usually true. The lower cost and easier handling of the 

 latter therefore give it the preference. It is possible that the low- 

 grade sulphate, or the 24 per cent 'double-manure salt,' as it is often 

 called commercially, may be superior on account of its magnesia- 

 content, but this has not yet been fuUy demonstrated. 



"The influence of proper fertihzation is not transient. The gains 

 from it have been greater in the sixth and the last year of some of 

 our experiments than at any time before. In one case, these gains 

 have exceeded 1,100 bushels an acre. Where the crops of the fuU 

 years are not too high, the yields usually have been greatly steadied 

 by proper fertilization. 



"In aU our experiments, the action of manure has proved to be 

 practically identical with that of a commercial fertilizer rich in 

 nitrogen and phosphorus. Their successes and failures have coincided 

 with but two exceptions, and in those cases moisture rather than 

 plant-food was apparently the controlling factor. The commercial 

 nitrates and blood have acted more quickly than the manure, and 

 the potash in the latter has apparently been less effective than that 

 in the commercial forms. 



"In general, the influences that have materially increased the 

 yields have also increased the growth. This is true generally, unless 

 either occurs to an abnormal extent. The phosphates seem to be a 

 partial exception to this rule, and mild injuries also may stimulate 

 yield at the expense of growth. 



"Manure and potash are the only fertilizing materials that have 

 shown a consistent benefit on the average size of the fruit. This is 

 doubtless associated with their favorable relations toward available 

 moisture, which is the chief determiner of fruit-size. Above a rather 

 indefinite point, however, the size of the crop on the tree becomes the 

 dominant influence on fruit-size. Proper' thinning and moisture 

 conservation, therefore, are the most important means of improving 

 the average size of fruit. 



"The red colors in apples can not be increased materially by any 



