Issued September 10, 1912. 
HAWAII AGRICULTURAL EXPERIMENT STATION, 
E. V. WILCOX, Special Agent in Charge. 
Bulletin No. 28. 
THE EFFECT OF MANGANESE ON 
PINEAPPLE PLANTS 
AND 
THE RIPENING OF THE 
PINEAPPLE FRUIT. 
BY 
E. V. WILCOX, 
Special Agent in Charge, 
AND 
W. P. KELLEY, 
Chemist. 
UNDER THE SUPERVISION OF 
OFFICE OF EXPERIMENT STATIONS, 
U. 9. DEPARTMENT OF AGRICULTURE. 
WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 
1912. 
