PREFACE
Since each of the four volumes of
this revised and new edition of The Citrus Industry is complete in
itself, the general plan of the work must necessarily be restated in each
volume. The first volume of the revised edition, History, World Distribution,
Botany, and Varieties, was published by the University of California
Division of Agricultural Sciences in 1967. The present volume, Anatomy,
Physiology, Genetics, and Reproduction, encompasses morphology,
anatomy, physiology, mineral nutrition, genetics, breeding, seed reproduction,
and growth regulators. The remaining two volumes, Production Technology and
Biology and Control of Pests and Diseases, are in course of preparation;
the dates of publication, however, cannot yet be announced.
The first edition of The Citrus
Industry, published in two volumes, served for more than two decades as the
classic reference work on the biology and culture of citrus throughout the
world. The first volume, History, Botany and Breeding, edited by H. J.
Webber and L. D. Batchelor, was published by the University of California
Press in 1943, followed by two later reprintings.
A larger printing of the second volume, Production of the Crop, edited
by L. D. Batchelor and H. J. Webber, was published in 1948 by the University of California Press. By the l960’s, it had
become apparent that many sections of the original volumes had been rendered
obsolete by technological advances and the acquisition of new basic knowledge
merely touched upon or not considered in the original edition.
Prompted by Dean A. M. Boyce and
other colleagues, I agreed to serve as editor for a new, revised edition.
Revision of The Citrus Industry was initiated on July 21, 1961, as Citrus Research Center and Agricultural
Experiment Station Project 2015. Because of substantial expansion of coverage,
it became necessary to divide the subjects originally covered in Volume I of
the first edition into two volumes. Thus, the present volume includes much of
the subject matter that appeared in the first volume of the original work. At
the same time, most chapters in this volume represent new treatments of their
subjects, reflecting the broader base of experience and information available
to the authors as a result of the increased tempo of citrus research in the decades
since World War II.
All of the authors of chapters in
this volume are members of the staff of the University
of California, Riverside,
closely affiliated with the Citrus Research Center
and Agricultural Experiment Station at Riverside.
Their treatment of subjects therefore tends occasionally to exhibit a regional
perspective, although improved communications and transportation in the past
few decades has made it possible for citrus researchers to be more cognizant of
developments in other countries than for contributors to the original volumes.
This new edition of The Citrus
Industry is intended to present a comprehensive view of all phases of the
industry to a broad readership of researchers, administrators, teachers,
students, and knowledgeable growers. An effort was made to present material
clearly, yet scientifically, so that it might be understood by an intelligent
readership. The editor, however, considered it essential that scientific
principles on which various practices are based should be explained. Some parts
of this volume, therefore, may present material of a highly technical nature
best followed by specialists. Literature reviews for most chapters in the
volume were completed with 1966 citations, although some authors were permitted
to add significant new material during the proofreading of page proofs.
In the first edition, general
morphology, histology, and physiology of citrus were treated in a single
chapter. In this volume, anatomy and physiology are presented separately in the
first two chapters.
Chapter 1, “The Anatomy of Citrus”
by Henry Schneider, provides greatly expanded coverage on anatomy. The author
has carried out a number of original studies and developed entirely new
illustrative material to present as detailed a treatment as possible of the
morphology and developmental anatomy of each plant organ.
Chapter 2, “The
General Physiology of Citrus” by Louis C. Erickson, concentrates primarily on a
discussion of those factors that influence the physiology and metabolism of
leaves and fruit. Special attention is also given to some of the physiological
disorders of citrus, including such recent problems as those arising from toxic
airborne pollutants.
Chapter 3, "The Mineral Nutrition of Citrus,” represents a greatly extended treatment of the topic as originally
handled by Homer D. Chapman in the first edition. Chapman’s new treatment
reflects a critical examination of the vast body of recent literature that has
enhanced our understanding of the effects of certain mineral deficiencies and
excesses on citrus physiology and fruit quality. In addition, methods of
controlling nutrient disorders are outlined briefly.
Chapter 4 represents a revision of
Howard B. Frost’s original chapter on seed reproduction. Robert K. Soost has
incorporated much new knowledge on flower biology, embryo development,
cytology, and seed germination into this review of the basic biology of seed
reproduction in the genus Citrus.
Two chapters in the original
edition have been synthesized by James W. Cameron into Chapter 5, “Genetics,
Breeding, and Nucellar Embryony.” Genetics and breeding and bud variation and
selection were covered separately in the first edition. Integration of bud
variation into the genetics chapter has produced a more unified treatment of disciplines
relating to variety improvement. Cameron has also traced the history and
progress of citrus breeding activities beginning with the early work of the U.
S. Department of Agriculture and indicated the impact of nucellar embryony
research on citrus variety improvement.
In Chapter 6, C. W. Coggins, Jr.,
and H. Z. Hield examine “Plant-Growth Regulators.” Although much remains to be
learned about these substances and their role in citrus physiology, the authors
review the status of knowledge and research and discuss some of the current
applications of plant-growth regulators and their potential for the future.
The editor wishes to express his
deep appreciation to the authors of the various chapters for their wholehearted
cooperation and patience during preparation of this volume. A number of authors
also found time despite their busy schedules to assist in the review of
chapters by their colleagues.
Gratitude must also be expressed to
those who assisted in reviewing parts of the text dealing with their particular
specialties and fields of research. Reviewers were as follows: Chapter 1,
Katherine Esau, W. W. Thomson, L. C. Erickson, E. S. Ford, and Shirley C.
Tucker; Chapter 2, W. W. Jones, Walton B. Sinclair, and Franklin C. Turrell;
Chapter 3, Paul Smith and T. W. Embleton; Chapter 4, James W. Cameron, Henry
Schneider, and Philip C. Reece; Chapter 5, J. R. Furr, William C. Cooper,
Philip C. Reece, and Robert K. Soost; and Chapter 6, William C. Cooper, L. N. Lewis, L. P. Batjer, and C.
H. Hendershott.
The photograph of Robert W. Hodgson
for the dedicatory page was provided by Evelyn Hodgson, who was also helpful in
reviewing the biographical material on her late husband. C. A. Schroeder
assisted in providing information for the biographical section.
The dedicatory photograph of Howard
B. Frost was generously furnished by his daughter, Mrs. L. W. Towner.
Biographical assistance on Dr. Frost was provided by his son, Robert H. Frost,
and his brother, Henry Frost.
I wish also to express my thanks
for their assistance on editorial and publication problems to William W. Paul,
manager of Agricultural Publications, and Lucy G. Lawrence of his editing
staff.
Walter Reuther
Riverside, California
July, 1968