142 MAINE! AGRICULTURAL EXPERIMENT STATION. I904. 



The potash was applied in the form of sulphate instead of 

 muriate because it is commonly held that the sulphate produces 

 a better quality of potatoes. Unpublished results of experi- 

 ments by this Station do not confirm this opinion. Although 

 this formula did as well with early planted potatoes as the com- 

 mercial fertilizers with which it was compared, it had a tend- 

 ency to prolong the period of growth, with the result that on late 

 potatoes, particularly in the northern part of Aroostook County, 

 the vines were green and vigorous at the time of the first severe 

 frost, which this year was early, September i. The other parts 

 of the fields, planted with the standard commercial fertilizers, 

 stood the frost much better than these tenderer vines grown on 

 the above formula. At digging, the yield with late planted 

 potatoes was larger and the individual potatoes were larger and 

 better matured on the standard brand of mixed goods than on 

 the above formula. For late planting with a short season it 

 would probably be advantageous to use a formula with more 

 water soluble nitrogen and more available phosphoric acid, as 

 an excess of this latter seems to hasten the ripening of the crop. 

 Some such a formula as the following might be used : 



a complete formula (no. 2) eor 3oo bushels potatoes. the 

 large Excess oe phosphoric acid will tend to early 

 maturity. eor one acre}. 





1 



<D 



m 

 P 



bt>C 



&■ ft 



1 



a . 

 a is 



c c 

 55 ft 



Phosphoric Acid 







1 

 <o 



< a 



— - 

 



Eh ft 



85 fi 



■£ 3 



C O 



0, a 





200 

 200 

 100 

 500 

 200 



32 

 11 

 13 











15 



32 









65 



70 









100 













Total 



1,200 



56 



4.7 



SO 

 6.7 



102 



8.5 



100 





8.3 







I * Seventy -five pounds of sulphate of ammonia could be well used in place of 100 

 pounds of the nitrate. 



1 150 pounds ordinary dried blood or 200 pounds cotton seed meal might be used 

 in place of the high grade dried blood. 



