This book is largely based upon investigations by the authors. The lack of exact knowledge and the frequently grossly inaccurate statements regarding the nature and extent of the root systems of vegetable crops have shown the need for intensive study. In dealing with the various vegetable crops the usually very meager data from other investigations have been added to present, so far as possible, a general view of root development of vegetable crops in the United States. No attempt has been made to include all of the root investigations in foreign countries but enough has been given to supplement adequately those in America and, it is believed, to include most of the important findings. The literature cited will direct the student who may wish to look further into foreign investigations.
The present work is a companion volume to Weaver's "Root Development of Field Crops." It is designed for the use of investigators and producers as well as to meet the needs of 'students of vegetable gardening.
In the study of root systems in relation to cultural practice, Thompson's "Vegetable Crops," Bailey's "The Principles of Vegetable Gardening," and similar works have been found very helpful. But in all cases original sources have been freely consulted in an attempt to correlate the root relationships with gardening practice.
All of the drawings with the accompanying root descriptions are original. Because of the great labor and expense involved in this work it could not have been accomplished except for the encouragement and financial support given by the Carnegie Institution of Washington. To this Institution the authors are under deep obligation for permission to publish this book as a companion volume to "Root Development of Field Crops." The authors are further indebted to Dr. Herbert C. Hanson for valuable assistance in the excavation of the roots at Lincoln. The senior writer is also indebted to a number of his students and especially to Mr. T. L. Steiger, Mrs. L. B. Mathews, and Miss Annie Mogensen for most of the illustrations and other valuable help. The authors wish to express their thanks to Professor T. J. Fitzpatrick for much helpful criticism in reading the manuscript and proof.
THE AUTHORS.
LINCOLN, NEBRASKA,
June, 1927.
Modifying the root environment -- Adaptation of roots to environment -- Root adaptation and crop production -- Interrelations of plant, soil, and climate -- Activities of roots in subsoil -- Method of root study -- Conditions for growth at Lincoln, Neb. -- Soils -- Number and size of plats -- Tillage -- Precipitation -- SoiI moisture -- Temperature -- Humidity -- Evaporation -- Conditions for growth at Norman, Okla. -- Soil -- Method of planting and tillage -- Precipitation -- Soil moisture -- Other factors -- Conditions for growth during the fall and winter.
Early development -- Relation of absorbing area to soil moisture -- Midsummer growth -- Maturing plants -- Summary -- Comparison with roots of field corn -- Relation of root habits to crop production -- Cultivation -- Fertilizers -- Suckering.
Southport White Globe onion -- Early development -- Effect of soil structure on root development -- Half-grown plants -- Mature plants -- Death of the older roots -- Yellow Bermuda onion -- Early development -- Half-grown plants -- Growth during the winter and second spring and summer -- Summary -- Other investigations on onions -- Relation of root system to cultural practice.
Early development -- Half-grown plants -- Maturing plants -- Summary.
Early development -- Growth during the winter -- Mature plants -- Summary.
Early development -- Mature plants -- Summary -- Other investigations on asparagus -- Habit of underground parts in relation to cultural practice -- Soil preference -- Transplanting -- Growing the seedlings -- The permanent bed -- Food storage in relation to harvesting -- Relation to mulch and humus -- Summary.
Mature root system -- Summary -- Relation of root system to cultural practice.
Early development -- Midsummer growth -- Maturing plants -- Root development of seed beets -- Summary -- Other investigations on beets -- Root habit compared with the sugar beet -- Root habits in relation to cultural practice.
Early development -- Half -- grown plants -- Midsummer development -- Root development of seed plants -- Root development compared with beet -- Summary -- Other investigations on Swiss chard -- Root development in relation to cultural practice -- Effect on soil structure.
Early development -- Half -- grown plants -- Mature plants -- Summary -- Other investigations on spinach -- Root development in relation to cultural practice.
Copenhagen Market cabbage -- Early development -- Midsummer growth -- Mature plants -- Summary -- Early Flat Dutch cabbage -- Mature root system -- Seed cabbage -- Development of roots and tops as affected by cultivation -- Other investigations on cabbage -- Relation of root system to cultural practice -- Cultivation -- Transplanting -- Relation of roots to competition and disease.
Early development -- Half-grown plants -- Maturing plants -- Summary -- Other investigations on cauliflower -- Root habits in relation to cultural practice.
Early development -- Later development -- Mature plants -- Summary -- Other investigations on kohl-rabi.
Early development -- Midsummer growth -- Mature plants -- Root development the second season -- Summary -- Other investigations on turnip -- Root development in relation to cultural practice.
Early development -- Later development -- Maturing plants -- Summary.
Mature plants -- Summary -- Root habit in relation to cultural practice.
Early Scarlet Turnip White -- tipped radish -- Early development -- Effect of soil structure on root development -- Two-months-old plants -- Mature plants -- Summary -- The Early Long Scarlet radish -- Early development -- Later development -- Mature plants -- Summary -- Other investigations on radish -- Root development in relation to cultural practice.
Mature plants -- Summary -- Other investigations on strawberries -- Root habits in relation to cultural practice.
Early development -- Later development -- Mature plants -- Summary -- Other investigations on peas -- The development and rôle of root tubercles -- Root development in relation to cultural practice.
Common or Kidney bean -- Early development -- Midsummer growth -- Mature plants -- Summary -- Lima bean -- Early growth -- Midsummer growth -- Maturing plants -- Summary -- Other investigations on beans -- Root habit in relation to cultural practice.
Early development -- Later development -- Maturing plants -- Summary -- Other investigations on okra.
Early development -- Midsummer growth -- Maturing plants -- Growth of carrots during winter and spring -- Mature plants -- Summary -- Other investigations on carrots -- Root habit in relation to cultural practice.
Champion Moss Curled parsley -- Early development -- Midsummer growth -- Summary -- Extra Double Curled parsley -- Other investigations on parsley -- Root habit in relation to cultural practice.
Early development -- Midsummer growth -- Plants in autumn -- Growths of roots during winter and spring -- Mature plants -- Summary -- Other investigations on parsnips -- Root habit in relation to cultural practice.
Methods of propagation -- Early growth -- Midsummer growth -- Mature plants -- Summary -- Root habits of certain sweet -- potato relatives -- Root habit in relation to cultural practice -- Soils and fertilizers -- Water relations -- Cultivation, rooting of vines -- Pruning and spacing -- Harvesting -- Summary.
Early root development and its relation to transplanting -- Later growth -- Maturing plants -- Summary -- Other investigations on tomatoes -- Experiments on root distribution, cultivation, and water conservation -- Root habits in relation to cultural practice -- Preparation of the soil -- Transplanting -- Spacing -- Cultivation -- Fertilizers -- Pruning -- Effects of roots on soil.
Early development -- Mature plants -- Summary -- Other investigations on eggplant.
Early development -- Half -- grown plants -- -- Maturing plants -- Summary -- Root habits in relation to cultural practice.
The cucurbits or vine crops -- Early development of cucumber -- Half-grown plants -- Maturing plants -- Summary -- Other investigations on cucumber -- Root system in relation to cultural practice.
Early development -- Half-grown plants -- Maturing plants -- Summary -- Other investigations on muskmelon -- Root habit in relation to cultural practice.
Early development -- Half-grown plants -- Mature plants -- Summary -- Other investigations on watermelons -- Root habits in relation to cultural practice.
Early development -- Midsummer growth -- Maturing plants -- Determination of the rate of growth -- Summary -- Other investigations on squash -- Root development in relation to cultural practice -- Roots of cucurbits in relation to disease.
Early growth -- Midsummer growth -- Maturing plants -- Summary.
Early growth -- Effect of soil structure on root development -- Half-grown plants -- Mature plants -- Summary -- Effect of cultivation on root and shoot development -- Other investigations on lettuce -- Relation of root system to cultural practice.