FOOD FOR PLANTS 45 



but indirect means of fighting the weevil is found in 

 the use of a fertilizer that develops and matures the 

 crop quickly. 



Experiments conducted by the North Carolina 

 Experiment Station throw valuable light on the 

 efficiency of fertilizer in cotton production and es- 

 pecially upon the common carriers of Nitrogen used 

 with phosphoric acid and potash. These tests show 

 that Nitrate of Soda was the most efficient of the 

 six sources of Nitrogen used in the experiment. It 

 produced the most lint, as is shown in the following 

 comparison of yields: 



Yield of 

 Seed Cotton Relative 



per Acre Efficiency 



Nitrate of Soda 699 lbs. 91.1 



Sulphate of A)nmonia 637 lbs. 85.4 



Nitrate of Lime 597 lbs. 85.4 



Cottonseed Meal 569 lbs. 81.4 



Dried Blood 550 lbs. 78.7 



Tankage 488 lbs. 69.8 



From these results it is shown that the Nitrogen 

 furnished by Nitrate of Soda has given a larger yield 

 of seed cotton than Nitrogen derived from any other 

 source tried. Under boll weevil conditions the late 

 or top crop is destroyed. Consequently, all that can 

 be done to induce the setting and maturing of the 

 earliest possible crop is of first consideration. Phos- 

 phoric acid is the element in fertilizer that induces 

 fruitfulness and early ripening, while Nitrogen 

 makes the body or frame of the plant for carrying 

 the fruit. Acid phosphate is the best source of phos- 

 phoric acid and Nitrate of Soda is the quickest and 

 most efficient source of Nitrogen. This is not only 



