Coffee Rust: Epidemiology, Resistance and Management

Ajjamada C. Kushalappa

• Publisher: CRC Press
• Year: 2019
• Print ISBN: 9781315891675
• eBook ISBN: 9781351087674
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

This highly informative monograph will provide a basic reference on coffee rust for both investigators in the field and those entering it. The research conducted has been organized based on principles of epidemiology and plant disease management, providing both theoretical and practical information. This approach enables discussion of the past, present and future of coffee rust research in broad plant patholog-ical areas of biology, epidemiology, genetics and breeding for disease resistance, fungicide technology and application, and disease management. In addition, an analysis of epidemics, breeding programs, and other rust management practices in India, Kenya and Brazil are included. This new text will contain over 45 figures and 40 tables for both investigators in the field and those just entering it.

Chapter 1

INTRODUCTION

Ajjamada C. Kushalappa

Table of Contents

• I. Importance
• II. History, Spread, and Distribution
• III. Symptoms
• IV. Etiology and Taxonomy
• V. Host Range
• References

I. Importance

After petroleum, coffee is the most important product in international world trade. Thus coffee growing is a very important agricultural occupation, upon which more than 50 countries are dependent for their economy, especially foreign exchange.¹

The amount of green coffee produced by various countries is presented in Table 1.² Almost 50% of total world coffee is produced by Brazil and Colombia. Total world trade involves annually about 60 million bags with another 19 million bags being consumed by the coffee producing countries themselves. The total value of the coffee crop can be estimated to be about $15 billion annually.² The two main cultivated coffee species are Coffea arabica and C. canefora, responsible for about 75% and 25% of total coffee production, respectively.³

Coffee rust, caused by Hemileia vastatrix Berkely and Broome, is one of the seven most important diseases and pests of tropical plants.⁴ It has been considered as one of the most catastrophic plant diseases of all time, along with blight of potato, stinking smut of wheat, black stem rust of wheat, club root of cabbage, and wilt of banana. It is a “classic plant disease”, because it was one of the earliest plant diseases to be studied scientifically and because of the major impact it had on the coffee industry in countries where it was introduced before effective control measures were discovered. The disease was largely responsible for the replacement of Arabica coffee plantations with tea in Sri Lanka, which was at one time Queen of the Orient and known everywhere as the greatest coffee producing land in the world. Coffee rust was introduced to Sri Lanka in the 1860s, and in a few years, coffee production decreased sharply in this country.⁵ The British, who were importing coffee from Sri Lanka, changed their drinking habits to tea as the coffee shipments stopped.⁶

Very soon other countries of the Orient and Africa began to take the place of Sri Lanka in the coffee business, but one after another they also suffered from rust. Amazingly, coffee plantations in the western hemisphere were not affected by rust until recently. Gradually, the western countries especially Brazil and Colombia, became major exporters of coffee.

The great initial impact of coffee rust in many Asian and African countries was reduced after the discovery and use of Bordeaux mixture in the 1880s and also by the replacement of susceptible C. arabica cultivars with more resistant C. canephora, mainly cv. Robusta. The importance of rust increased again when rust invaded the American continent in the 1970s with its large susceptible C. arabica plantations which are responsible for 80% of all Arabica production. Chemical control measures developed in Africa and Asia were soon transferred to Brazil and other American countries. Despite the effectiveness of various fungicides, mainly copper compounds, rust is still responsible for a yield reduction of 20% or more in various countries. In Brazil, the major coffee producing country, losses have been estimated to be about 30% if no control measures are taken.⁷

The damage of coffee rust is due not only to the reduction in the photosynthetic leaf surface area at the lesion site but also to the pathogen induced leaf fall. When the attack is severe, the whole plant may become defoliated, causing dieback of branches. The berry yield is reduced not only during the current year due to the reduction in the photosynthetic area but also in the following year by reduction of fruiting branches. Although the plants may become weakened, they normally recover from rust attacks, especially when nutrition is adequate. Death of plants may occur only with extremely high disease severity.

The several names given to the disease are listed in Table 2. The most commonly used names are coffee leaf rust or orange coffee rust. The orange coffee rust should not be confounded with powdery coffee rust, caused by H. coffeicola.

The importance of this book is partly due to the scattered way most research on leaf rust has been published, often only in congress abstracts, dissertations, and research reports with very restricted distribution.

Many of the recent publications are cited in the Review of Plant Pathology. A bibliography on coffee, including coffee rust, has been published by PROMECAFE/IICA,⁸ and an annotated bibliography by CAB/CMI.⁹ Many of the earlier works are included in the publications listed by Stevenson and Beam,¹⁰ More recently, reviews have been published, such as those of Nutman and Roberts¹¹ and Rayner,¹² describing much of the work done in East Africa, Mayne with special reference to India,¹³ Chaves and collaborators,¹⁴ Saccas and Charpentier,¹⁵ Waller,⁶ and a symposium book edited by Fulton.¹⁶ During the past decade, in various countries of Latin America many informative bulletins and advisories have been published to create awareness among growers and extension workers, and to furnish basic knowledge to local researchers. Many originated from special conferences organized by the Instituto Interamericano de Cooperacion para la Agricultura (IICA). Some of the major organizations that took the initiative to organize national and international meetings, to conduct or finance research, and to train technical people were the Instituto Brasileiro de Cafe (IBC), Brazil; PROMECAFE/IICA, Costa Rica; Comision Mexico-Guatemala para la Prevencion y Control de la Roya del Cafeto, Guatemala; Junta del Acuerdo de Cartagena (Junac), Peru; Organismo Internacional Regional de Sanidade Agropecuaria (OIRSA), El Salvador, etc.

TABLE 1
Green Coffee Production by Various Countries (in 1000 Bags of 60 kg)²

TABLE 2
Different Names of Coffee Rust

II. History, Spread, and Distribution

The origin of coffee rust is controversial. Since C. arabica originated in Ethiopia, it has been suggested that the rust also originated in the mountainous regions of this country,⁵ where it has also native names. Some believe that it originated from central Africa.¹⁷ Theories on the origin of rust will be discussed in detail in Chapter 6, in relation to its coevolution on different coffee species. Probably the first report of rust was that of a British explorer, in 1861, in the region of Lake Victoria of Kenya in east Africa.¹⁸ The first record of coffee rust in cultivated trees was in Sri Lanka in 1869. F...

Table of contents

• Cover
• Title Page
• Copyright Page
• Preface
• The Editors
• Contributors
• Table of Contents
• Chapter 1 Introduction
• Chapter 2 Biology and Epidemiology
• Chapter 3 Rust Management: An Epidemiological Approach and Chemical Control
• Chapter 4 Chemical Control Practices around the World
• Chapter 5 Natural Enemies and Biological Control
• Chapter 6 Resistance
• Chapter 7 Breeding Programs
• Index