Handbook of Environmental Physiology of Fruit Crops

Bruce Schaffer, Peter C. Andersen

• Publisher: CRC Press
• Year: 2018
• ISBN:
  9781351442787
• Edition: 1
• Topic: Ciencias biológicas
• Subtopic: Botánica

These exciting new companion handbooks are the only ones of their kind devoted solely to the effects of environmental variables on the physiology of the world's major fruit and nut crops. Their cosmopolitan scope includes chapters on tropical and temperate zone species written by scientists from several continents. The influence of environmental factors, such as irradiance, temperature, water and salinity on plant physiology and on vegetative and reproductive growth, is comprehensively discussed for each crop. In addition to being a thorough and up-to-date set of textbooks, the organzation of the two volumes makes them an excellent reference tool. Each chapter focuses on a single crop, or a group of genetically or horticulturally related crop, and is appropriately divided into subsections that address individual environmental factors. Some chapters emphasize whole-plant physiology and plant growth and development, while other chapters feature theoretical aspects of plant physiology. Several chapters provide botanical background discussions to enhance understanding of the crop's response to its environment.

Chapter 1

Introduction

Bruce Schaffer and Peter C. Andersen

Environmental variables modulate virtually all aspects of plant growth and development. The sum of the interactions between plant genotype and the environment determines plant phenotype and plant productivity. An understanding of environmental physiology is crucial in selecting optimum sites for a given species or cultivar, to minimize the deleterious impacts of suboptimal environmental conditions and to modify or create microenvironments that are conducive to maximum productivity. Moreover, the establishment of a database on environmental physiology is essential in an era of agricultural sustainability where agricultural inputs are becoming increasingly scrutinized.

Previous review articles concerning physiological, and growth and developmental responses of fruit crops to the environment have typically addressed a specific or multiple plant response to a single environmental factor, or alternatively, a specific plant response to multiple environmental variables. In addition, few articles integrate environmental physiology with plant growth and development. Often a large volume of literature from many sources must be compiled to obtain a comprehensive coverage of the environmental physiology of a specific crop.

The purpose of this volume of The Handbook of Environmental Physiology of Fruit Crops is to provide a comprehensive reference source on the responses of temperate fruit crops to the environment. This book addresses plant responses to abiotic variables (light, temperature, water, wind, salinity, and air pollution) and when possible integrates whole plant physiology with production horticulture. The volume was designed to appeal to a wide audience of researchers, extension workers, and students interested in fruit crop physiology and is written on a level that is commensurate with a general understanding of plant physiology.

We have relied on the broad horticultural definition of fruit crops to include woody or herbaceous perennial trees, shrubs, or vines with the edible portion (fruit) an expanded and ripened ovary with attached and subtending reproductive structures.^1,2 At times we have strayed from this definition. For example, we have included strawberry, which is often grown as an annual. Most of the commercially-important temperate fruit crops are contained in this volume. However, some crops were omitted due to either the lack of available information and/or the inability to locate a qualified author. A few “warm temperate” crops, such as persimmon, are discussed in this volume although they can be cultivated in subtropical and tropical regions. Although an attempt was made to solicit chapters from highly qualified individuals, clearly there are many more individuals who would have been eminently qualified as authorities on certain crop species.

This book is generally divided according to fruit crops species or related species of fruit crops. In one chapter, “Temperate Nut Species”, many species have been combined in the discussion because of the limited available database. Crop origin, genetic diversity, botany, and ecology were often included to facilitate a discussion of environmental physiology. There is a great deal of flexibility in the orientation, content, and style of each chapter. The terminology and abbreviations used to define physiological variables are consistent within each chapter. However, there are some differences in terminology among chapters, reflecting the lack of a commonly accepted terminology among plant physiologists. Although the authors attempted to comprehensively discuss plant responses to abiotic factors, to some extent chapters reflect the authors’ particular research specialty. For certain crops such as grape, apple, and stone fruit there has been much research on environmental physiology focusing on leaf gas exchange, water relations, and carbon partitioning. The extensive database for those crops presented the authors with much flexibility to determine the scope and content of their material and allowed for an integration of several physiological responses. In contrast, little information was available for some of the fruit and nut species, and consequently, the discussion often relied more heavily on growth and developmental responses.

In addition to serving as a useful reference source, this volume of The Handbook of Environmental Physiology of Fruit Crops will underscore the limitations of our knowledge in this area and will help delineate areas in need of further research.

The physiological, growth and developmental responses in relation to the interaction among multiple environmental stresses is a topic that warrants increasing emphasis. For most fruit and nut species the database concerning the influences of environmental variables must be expanded to allow for the development of models that maximize plant productivity and resource use efficiency.

LITERATURE CITED

1.  Barden, J. A. and Halfacre, R. G., Horticulture, McGraw Hill, New York, 1979.

2.  Soule, J., Glossary for Horticultural Crops, John Wiley and Sons, New York, 1985.

Chapter 2

Apple

Alan N. Lakso

CONTENTS

I.	Introduction
	A.	Limiting Factors
	B.	Growth and Development
	C.	An Ecophysiology Viewpoint
II.	Radiation
	A.	Bases of Orchard Productivity
	B.	Orchard Light Interception
		1.	Factors Affecting Light Interception
		2.	Value of Orchard Models
	C.	Short-Term Responses to Radiation
		1.	Photosynthesis
		2.	Short-Term Carbon and Water Balance Effects
	D.	Long-Term Responses of Exposure to Radiation
		1.	Photosynthesis
			a.	Fruiting
			b.	Potential Mechanisms of Light Exposure Effects
			c.	Flower Bud Development
			d.	Fruit Growth and Set
			e.	An Example of Utilization of Physiology
III.	Temperature
	A.	General Effects
		1.	Effects of Yearly Patterns of Temperature
		2.	Growing Season Temperature Effects
		3.	Seasonal Respiratory Costs
		4.	Photosynthesis
	B.	High Temperature Effects
		1.	Fruit Set
		2.	Water Relations with High Temperatures
	C.	Low-Temperature Effects
		1.	Cold During the Growing Season
		2.	Dormancy
		3.	Cold Hardiness
IV.	Water Deficits
	A.	Terminology and Fundamentals
		1.	Total Water Potential (Ψw)
		2.	Osmotic Potential (Ψπ)
		3.	Turgor Potential (Ψp)
		4.	Significance of Plant Resistance to Control of Leaf Water Potential (Ψ1)
	B.	Orchard Microclimate and Management Considerations
		1.	Whole-Crop Water Use
	C.	Overview of Apple Water Relations
		1.	Drought Avoidance/Escape
		2.	Drought Tolerance by Maintaining High Water Potentials
			a.	Reduction of Water Loss
				i.	Stomatal and Cuticle Resistances
				ii.	Reduction of Radiation Absorbed
				iii.	Reduction of Leaf Area
			b.	Maintenance of Water Uptake
		3.	Drought Tolerance at Low Water Potentials
			a.	Maintenance of Turgor
		4.	Cell Elasticity and Size
V.	Flooding
	A.	Growth and Productivity
	B.	Differences in Rootstock Response
	C.	Sensitivity and Response to Pathogens
VI.	Other Environmental Factors
	A.	Salinity
	B.	Pollutants
		1.	Air Pollutants
		2.	Acid Deposition
	C.	Atmospheric CO2
VII.	Conclusions
	A.	Needs for Future Research
Acknowledgments
References

I. INTRODUCTION

The environmental physiology of the apple (Malus domestica Borkh.) has been extensively researched compared to many other fruit crop species. Since a comprehensive review of this entire knowledge base is beyond the scope of a review of this size, this chapter will be interpretive rather than comprehensive, emphasizing (1) knowledge developed primarily since the last major reviews on radiation, water, temperature, etc. (mostly work in the 1980s), (2) integration of knowledge with a view toward whole-plant and crop physiology, (3) interactions of physiological responses to multiple environmental factors in the field, and (4) identification of remaining roadblocks and new opportunities to apply this knowledge to solve problems of apple production.

The reader is referred to several excellent reviews of apple physiology and morphology on which this chapter is based^{1, 2, 3, 4, 5, 6, 7, 8, 9} as well as general reviews and books that are applicable.^{10, 11, 12, 13} The reader is referred to several useful books and reviews and references therein for methods and techniques.^{14, 15, 16, 17, 18} This review will emphasize carbon and water relations of apple trees growing in temperate zones. Since the apple is grown for fruit production, the discussions will primarily concern the range of conditions normally occurring in a producing orchard rather than in extreme conditions.

A. LIMITING FACTORS

Before discussing individual environmental factors that affect productivity, it is worthwhile to consider the concepts of limiting factors. Monteith¹⁹ has emphasized that each resource (light, CO₂, water, nitrogen, phosphorus, boron, etc.) and each process (light interception, photosynthesis, respiration, leaf area development, translocation, nutrient uptake, nitrogen reduction, protein synthesis, hormone transport, ion exchange processes, etc.) is essential for productivity. However, that does not mean that any one resource or process is necessarily controlling the variations in crop productivity. It is important to understand that many processes can be essential without ever being important to the variations in crop productivity (for example, water is essential, but accounts for little of the variations in productivity in irrigated orchards). The primary role of the crop physiologist is to determine which resources or processes are limiting crop performance at any given time and ideally determine a feasible way to overcome the limitation.

There is no a priori reason to believe that any one resource or process is always limiting to a crop. It is much more likely that there are periods of differing resource or process limitations during the developmental stages of the crop. Environmental resources (light, water, etc.) or conditions (temperature, humidity) may limit crop development at certain times depending on the crop sensitivity and how extreme the environment may be. Additionally, plant status, such as crop load, may greatly change the relative sensitivity of the plant to an environmental stress or resource limitation.

Interactions of plant development and the environment should be kept in mind when evaluating the plant’s response to any particular environmental factor. A useful analogy is that of pullin...