58 AGRICULTURE OF MAINE. 



These results show that plant foods are not the limiting factors 

 in apple production in this particular orchard. 



In 1907, a report was made upon an experiment in fertilizing 

 apples at the New York Station. This experiment had been 

 running for twelve years. The fertilizers used were wood ashes 

 and acid phosphate. Here again the results were considered 

 negative, having barely paid for the cost of the fertilizers. Yet 

 a close scrutiny of the figures from this experiment reveals a 

 rather peculiar state of affairs. In the plots under treatment 

 there were five varieties of apples used : Baldwin, Fall Pippin, 

 Rhode Island Greening, Northern Spy and Roxbury Russet. 

 While the combined yields of all of these varieties show but little 

 benefit from fertilizers, the results obtained by considering the 

 varieties separately show that there was a striking difference in 

 the response of the different varieties. Baldwin and Rhode 

 Island Greening made practically no response to fertilizer appli- 

 cations, while Spy and Roxbury Russet showed an annual 

 average gain of 125 bushels per acre. This offers startling 

 proof that the limiting factors for one variety of apples may not 

 be the same for another variety. No nitrogen was used in any 

 of the treatments, hence we have no proof but that a nitrogenous 

 fertilizer might have proved of great benefit to this orchard. 



A third experiment is one that has been carried on since 1889 

 by the Massachusetts Experiment Station. This work was 

 reported upon in 1911 by Director Brooks. The fertilizers used 

 were bone and muriate of potash, wood ashes, bone meal and 

 sulphate of potash, and barnyard manure. In growth of tree, 

 as represented by the circumference of the butts, the greatest 

 results were obtained from barnyard manure. Trees in this 

 plot had increased in circumference about 11 inches more than 

 the trees which had received no fertilizers. The next best gain 

 was made by the use of bone and sulphate of potash. Consid- 

 ering all varieties, the results being for an average of 20 years, 

 the treatments yielded as follows : 



No fertilizer .' . 88 bbls. per acre 



Wood ashes 286 " " " 



Bone and muriate of potash 322 



Bone and sulphate of potash 488 



Barnyard manure 55^ 



The largest fruits have been picked from the treatment re- 

 ceiving bone and sulphate of potash and the smallest from the 



H It 



