Chapter 1

GENERAL PRINCIPLES UNDERLYING PLANT CULTURE

Chapter Page

I.--INTRODUCTION TO PLANTS 3

II.--ROOTS 9 Uses of roots to plants 9 Habit of growth of roots 11 Conditions necessary for root growth 20

III.--SOILS 23 Relation of soil to plants 23 Classification of soils 26 How were soils made? 30 Soil texture 37

IV.--RELATION OF SOILS TO WATER 39 Importance of water to plants 39 Sources of soil water 40 Attitude of soils toward water: Percolation Absorption from below Power to hold water 40 The effect of working soils when wet 45

V.--FORMS OF SOIL WATER 48 Free water 48 Capillary water 49 Film water 50

VI.--LOSS OF SOIL WATER By surface wash By percolation and leaching By evaporation By transpiration How to check these losses 53

VII.--SOIL TEMPERATURE 57 How soils are warmed 58 How soils lose heat How to check loss of heat 59 Conditions which influence soil temperature 60 Value of organic matter 61

VIII.--PLANT FOOD IN THE SOIL 63

IX.--SEEDS 70 Conditions necessary for sprouting 70 Seed testing 75 How the seeds come up 77 Use of cotyledons and endosperm 79

X.--SEED PLANTING 81 Depth of planting: Operation of planting Planting machines 81 Seed classification 85 Transplanting 87

XI.--SPADING AND PLOWING 90 Spading the soil 90 Plowing 91 Why we spade and plow 91 Parts of a plow 92 Characteristics of a good plow 95 The furrow slice 96 How deep to plow 96 "Breaking out the middles" 97 Ridging the land 98 Time to plow 98 Bare fallow 100

XII.--HARROWING AND ROLLING 101 Harrowing: Why we harrow Time to harrow 101 Types of harrows 102 Rolling 106

XIII.--LEAVES 108 Facts about leaves 108 The uses of leaves to plants: Transpiration Starch making Digestion of food Conditions necessary for leaf work 109 How the work of leaves is interfered with 115

XIV.--STEMS 120 What are stems for? 120 How the work of the stem may be interfered with 126

XV.--FLOWERS 128 Function of flowers 128 Parts of flowers 129 Functions of the parts: Cross pollination 130 Value of a knowledge of the flowers 134 Fruit 136