Vol. XXII OOXOBE)R 2^, 1921 No. 5 



JOURNAL OF 



AGRICUI/TURAlv 



RESEARCH 



CONTKNXS 



Page 



Relation of Soil Temperature and Other Factors to Onion 

 Smut Infection - ^ - - - - - - 235 



J. C. WALKER and L. R. JONES 



(Contribution from Bureau of Plant Industry and Wisconsin Agricultural Experiment Station) 



A Physiological Study of Grapefruit Ripening and Storage 263 



LON A. HAWKINS 



(Contribution (torn Bureau of Plant Industry) 



Absorption of Copper from the Soil by Potato Plants - 281 



F. C. COOK 



(Contribution from Bureau of Chemistry) 



PUBUSHED BY AUTHOMTY OF THE SECRETARY OF AGRICULTURE, 



WITH THE COOPERATION OF THE ASSOCIATION OF 



LAND-GRANT COLLEGES 



w:a.shingxon, d, c. 



