viii CONTENTS 



CHAPTER IV 



Paob 

 Soil Moisture: Its Classification, Movement and Influence on Root 



Distribution 47 



Classification of the Water in Soils and Plant Tissues — The Response of 

 Water to the Force of Gravity and the Evaporating Power of the Air; 

 the Relative Saturation; Resistance to Freezing — Movement of Water in the 

 Soil — Percolation; the Rise of Water by Capillarity; Lateral Movement of 

 Water in the Soil — The Distribution of Fruit Tree Roots as Influenced by Soil 

 Moisture — The Idea^ Root System — Specific and Varietal Differences in Root 

 Distribution — The Distribution of Tree Roots under Varying Conditions — 

 In the Hood River Valley, Oregon and in Ohio ; in a Gravelly Loam, Underlaid 

 by Hardpan, in Maine; in a Thin Gravelly Loam, Underlaid by Rock, in 

 Maine; in Dwarfs; the Influence of Soil Moisture; the Influence of Culti- 

 vation; the Influence of Soil "Alkali" — Applications to Orchard Practice — 

 Summary. 



CHAPTER V 



The Response of Fruit Plants to Varying Conditions of Soil Moisture 



AND Humidity 66 



Influence of Soil Moisture on Vegetative Growth— New Shoots and their 

 Leaves; Annual Rings and Trunk Circumference; Moisture Supply and the 

 Growth Period in Early Spring; the "Second Growth " of Midsummer or Late 

 Summer — Influence of Water Supply on the Development of Fruit — Size; 

 Yield; Shape and Color; Composition; Disease Resistance and SusceptibiHty 

 — Residual Effects of Soil Moisture — On Vegetative Growth; on Yields — 

 Influence of Atmospheric Moisture on Growth — In General; Russeting of 

 Fruit; Fruit Setting — Summary. 



CHAPTER VI 



Pathological Conditions Associated with Excesses and Deficiencies in 



Moisture 83 



Disturbances Due to Moisture Excesses — The Splitting of Fruit; (Edema; 

 Fasciation and Phyllody; Chlorosis; Rough Bark or Scaly Bark Disease; 

 Watercore — Disturbances Due to Moisture Deficiencies — Defoliation, 

 Premature Ripening of Wood — Dieback — Cork, Drought Spot and Related 

 Diseases — Fruit-pit; Cork; Surface Drought Spot; Deep-seated Drought 

 Spot; Dieback and Rosette; Bitter-pit; Jonathan-spot; Black-end — Silver 

 Leaf — Lithiasis — Summary. 



SECTION II 



Nutrition 



CHAPTER VII 



Plant Nutrients and Their Absorption 101 



Distribution of Elements Found in Ash — In Tissues of Different Kinds; in 

 Tissues of Different Age; at Different Seasons — Absorption — The Osmotic 

 System — Displacement — Availability of Ash Constituents — Availability 

 and Solubility Distinguished; Factors Influencing Solubility; Availability of 



