CONTENTS 
Page 
Introductions... 220, 6500 ead aoe he eee eee; aaa. ae 5 
History of plantings en unsuitable soils... . 252... oe eee eee 5 
Appearance of plants on unsuitable soils................--..---- ease 6 
Prelimingry inyosbieetieng ss + cen dere -.44- 4 sand +asbb sagen a es 6 
Investigations of pimeapmleisgilesea) ones Joe ean ee cS eke te tet gue ee 
Chemical survey of the pineapple soils of Porto Rico...............-.--...-- 8 
Pinespple satis OF Ob Ner COUMEICG= «cc % teen crates aeiriees amen eee cect eee eee 18 
Pot.experiments with different types of soil............-.-------------+-+- 20 
Experiments with plants grown in small field plats............-.....---.... 26 
Conclusions from soil investigations. .........------.--------+--- olaeereaeiae 27 
Inventive tions Of tie, CRIGrarth ssa 5 ee eS os ee eels a ele ie 29 
Previous work on, ime-tnduced se plorosis..2 2-25.20. -e eins cnwis See cece te Sees 
Effect of soil alkalinity and assimilable lime in causing chlorosis... .......- 31 
Treatment of chlorotic plants with iron and other salts..................--- 32 
Ash content of green and chlorotic leaves.............------.-..----2---+- 34 
Enzymes in chlorotic and @reen leaves !-.0 222: 2. =. oo. poe 2-8. ee 39 
Effect. ohchhen tee chlorosis: foc.) .... 5% i- 5652 dc tee aa ee 42 
Conclusions from investigations of the chlorosis. ..........-..-..-.---------- 43 
Sunany (220.2. oem oe eee eee ee ee ee a eerie Oe 44 
Acknowledgment. 3. .0222c6. 52 Oo et ee ee IS een: os. 5 eee 45 
ILLUSTRATIONS, 
Page. 
Puate I. Normal green plant and two stages of chlorosis ............. Frontispiece. 
II. Fig. 1.—Effect of carbonate of lime on the growth of pineapples. 
Fig. 2.—Effect of ferrous sulphate on chlorotic pineapple plants.... 22 
[ Bull. 11] (4) 
