Examines the broad subject of biological control of plant pathogens in a unified framework of concepts and principles. Among the principal themes is the fact that slight changes in an environmental factor often produce striking effects in plant-microbe interactions.

From the Preface:

Our original intention in writing this book was to revise and update our Biological Control of Plant Pathogens. However, it was clear already from the first efforts that we were writing a completely new book and that was the first volume would therefore still be useful to workers in this field. Furthermore, the quantity of new information on biocontrol was so large that to incorporate it into a second edition was almost impossible. Our decision to build on and extend the principles of the first book, rather than to revise it, was strengthened when the American Phytopathological Society (APS) suggested in early 1982 that they reprint our first book which had been out of print for two and a half years. This solved the problem of continued availability of the first book and led to our agreement that APS would also publish the second book as a companion volume.

This book differs from the first in several important respects. The broad subject of biological control of plant pathogens – whether of aerial or subterranean plant parts, whether viroids, viruses, prokaryotes, fungi, or nematodes – is treated in an integrated, unified framework of concepts and principles. Relevant information is included from soil physics on the water and gaseous environment of soil, and from soil microbiology on microbial biomass and biomass turnover in the soil. Mechanisms of biological control are emphasized and related to current concepts of plant physiology, soils, and microbiology. Although some of the aspects covered are outside our expertise, we hope that our perspective as biocontrol specialists may provide useful insights to the experts of these subjects and motivate them to apply these phenomena in biological control. One of the principal themes of this book, only briefly discussed in our early work, is that slight changes in an environmental factor often produce striking effects in interacting among microorganisms, or between them and the crop plant, and provide an effective means of achieving biological control of plant pathogens.

The Nature and Practice of Biological Control of Plant Pathogens

Why Biological Control?

Biological Control Answers Many Agricultural Problems
Increasing Crop Production Within Existing Resources
Avoiding Development of Pathogen Resistance to Chemicals
Adopting Practices Compatible with Sustainable Agriculture
Biological Balance
Effects of Agriculture on Biological Balance
Historical Constraints on the Use of Biological Control with Antagonists
The Potential of Gene Manipulation

Developmental History of Biological Control of Plant Pathogens

Introduced Antagonists
Resident Antagonists
Mycoparasites
Suppressive Soils
Some Landmark Events of the Past Fifty Years
Conferences and Symposia on Biological Control

Components of Biological Control

Definition of Biological Control
The Pathogen as a Component of Biological Control
Antagonists as Components of Biological Control
The Host Plant as a Component of Biological Control
Role of the Abiotic Environment in Biological Control
Biological Control Related to Other Controls

Approaches to Biological Control

Biological Control of Inoculum
Biological Destruction of Dormant Propagules
Prevention of Inoculum Formation
Displacement of the Pathogen in Crop Residue
Manipulation of Factors Inherent in the Pathogen
Biological Protection Against Infection
Protection of Plant Material
Protection of Roots with Biological Seed Treatments
Biological Protection of Foliage and Flowers
Inoculation of Pruning Wounds with Antagonists
Cross Protection and Induced Resistance
Virus Control by Cross Protection
Control of Fungus Pathogens by Cross Protection
Use of Multilines and Variety Mixtures
Vesicular-Arbuscular Mycorrhizal Fungi

The Pathogen in Biological Control

Food and Energy Management by Parasites During Parasitism
Preventing Accumulation of Excess Nutrients
Polluting the Infection Site or Lesion
Modifying the Physical Environment of the Host
Converting Food into New Propagules
Micovirus Infections and Hypovirulence
Hypovirulence in Endothia parasitica and its Role in Biocontrol
Pathological Effects of Hypovirulence in Rhizoctonia solani
Hypovirulence in Gaeumannomyces graminis var. tritici
Maintenance and Defense in the Absence of a Suscept--The Bear Market After a Bull Market
Diversification as a Method of Resource Management; Saprophytic Survival
Survival as Dormant Propagules in Soil
Initiation and Maintenance of Growth in Response to a Suscept--The Beginning of a Bull Market After a Bear Market Inoculation
Pathogen Response to the Host; Water Requirements of Pathogens

The Host and Biological Control

Plant Water Potentials
Plant Water Potentials for Pathogen Growth and for Biological Control with Antagonists
Influence of Plant Water Potentials on Resistance of Plants to Pathogens
Plant Temperature
Leaf Temperatures for Growth of Pathogens and for Biological Control by Antagonists
Influence of Plant Temperature on Resistance of Plants to Pathogens
Predisposition by Chilling Injury and Freezing
Oxygen in Plants and in the Root Zone
Mineral Nutrition and Ionic Balance
Nutritional Environment and Antagonistic Interactions Among Microorganisms on Plant Surfaces
Root Exudation, Dynamics of Root Growth, and Colonization of the Rhizophere and Rhizoplane
Exudation and Leaching from Aerial Parts
Colonization of Aerial Parts by Microorganisms
Debris as a Source of Nutrients on Aerial Parts of Plants
Protection of Leaves and Flowers by the Phylloplane Microbiota
Compartmentalization and Biological Control of Decay in Trees
The Active Role of the Host in Biological Control
Cell - Cell Communication Between Plants and Microorganisms
Cell Membrane Integrity as a Factor in Success of the Host-Pathogen Interaction
Host Defense by Physical or Chemical Containment of the Pathogen
Cross Protection and Induced Resistance
Direct Antagonism of the Pathogen by a Nonpathogen
Induced Resistance
Enhanced Host-Plant Resistance with Mycorrhizae

The Soil Ecosystem and Biological Control

Soil Water and Aeration as Factors in Biological Control
Some Basic Concepts
Water Potential Requirements for Growth, and the Relative Competitive Advantage of Microorganisms in Soil
Soil Water Content and Diffusion of Solutes
Water-Filled Pores and the Motility of Soil Microorganisms
Soil Aeration and Biological Control
The Microbial Biomass of Soil
Amounts and Methods of Measurement; Influence of Heat Treatments and Fumigation
Soil Fungistasis
Crop Residue Decomposition in Relation to Biological Control
Pathogen-Suppressive Soils
General and Specific Suppression
Soils Suppressive to Gaeumannomyces graminis var. tritici
Fusarium-Suppressive Soils
Phytophthora-Suppressive Soils
Pythium-Suppressive Soils
Biological Control of Rhizoctonia solani in Suppressive Soil

Introduction of Antagonists for Biological Control

Antagonists as Soil Treatments
Introduction of Hyperparasites
Introduction of Saprophytes for Colonization of Treated Soil
Antagonists Applied with the Planting Material
Biological Seed Treatments
Inoculation of Cuttings and Transplants
Postplanting Treatment with Antagonists
Postharvest Biological Control

Antagonistae Vitae

Agricultural Practices and Biological Control

Cropping System
Preplant Soil Treatments
Tillage
Organic Amendments
Flooding
Solar Heating of Soil
Fertilization and Adjustment of Soil pH
Methods and Date of Planting
Irrigation Practices
Modification of the Environment to Favor Antagonists
Alleviation of Predisposing Plant Water Stress
Selection of the Best Combination of Practices

Perspectives

Detection of Effective Antagonists
Unexploited Opportunities for Biological Control
Unusual Approaches to the Discovery of Biological Control
Biological Control in Less Developed Countries, and Some Lessons for the Agriculture of More Developed Countries
A Partner at the Feast
Expectations for Biological Control