iv CONTENTS 



Chapter Page 



6. Plant Hormones by P. W. Zimmerman 204 



Definition of Hormone • Brief Historical Picture and Recent Experi- 

 ments • Physiological Activities in Substances: Methods and Applica- 

 tions; Induction of Adventitious Roots; Propagation of Plants; Pre- 

 harvest Apple Drop; Inhibition of Growth; Fruit Set and Seedless Fruit; 

 Formative Influence of Growth Substa7ices • Other Subjects of Interest 

 Involving Plant Hormones: Absorption and Movement of Growth Sub- 

 stances; Light and Dark Effects; Tropic Curvatures; Anesthesia; Activa- 

 tion of Cinnamic Acid with Ultraviolet Light; Natural Influences; 

 Comparative Effectiveness of Adds, Esters, and Salts 



7. Dormancy in Buds 230 



Dormancy in Potato Buds • Dormancy of Gladiolus Corms and Cormels 

 • Forcing Dormant Buds of Deciduous Trees and Shrubs • Metabolic 

 Changes Induced by Chemicals That Force Dormant Potato Buds • 

 Metabolic Changes Induced by Ethylene Chlorhydrin Compared with 

 Effects of Other Chemicals Including Other Bud Forcers • Summary 



8. Plant Cell Membranes by Wanda K. Farr 260 



General Studies of Cotton Fiber Groivth • Broadening of the Experi- 

 mental Approach • Formation of the Cellulose Particles • Summary 



9. Plants Grown Under Controlled Environmental Con- 



ditions 285 



Plants Grown Entirely in Artificial Light • Growing Plants Under a 

 Combination of Sunlight and Artificial Light • The Carbohydrate 

 Nitrogen Ratio in Plants • Spectral Greenhouses • Some Effects of 

 Ultraviolet Rays on Plants • Miniynum Light Intensity for the Survival 

 of Green Plants • Light Measurement • Effect of Radiation on Trans- 

 piration • Environmental Conditions and the Development of Chlorophyll 

 Pigments • Environmental Conditions Modify the Microchemistry and 

 Anatomy of Plants • Some Lcnv-Temperature Effects • Summary 



10. Research on Insecticides by Albert Hartzell 343 



Efficiency and Mode of Action of Contact Insecticides • Fumigants • 

 Search for New Insecticides • Some Local Problems in Insect Control • 

 Summary 



11. Fungicide Investigations by S. E. A. McCallan 362 



Fungicidal Action of Sulfur • Fungicidal Action of Copper • The 

 Laboratory Slide-Germination Method of Evaluating Fungicides • 

 Greenhouse Methods of Evaluating Fungicides • Cumulative Error 

 Terms • Correlations Between Laboratory and Greenhouse Methods of 

 Testing Fungicides • New Fungicides • Past and Future 



12. Miscellaneous 386 



Factors for Color in the Production of Potato Chips • Physiological and 

 Biochemical Effects of Carbon Dioxide • Diurnal and Autumn Changes 

 in Leaves of Deciduous Plants • Concerning the Determination of the 

 Isoelectric Poirit of Protoplasm • Growth Substances arid Vitamin Bi for 

 Seed Treatment • Importance of the Mother-Tuber in the Growth of the 



