Disease Management in Cocoa: Comparative epidemiology of witches’ broom

Witches' broom is an important Southern and Central American disease of cocoa that is estimated to reduce annual world production by some six to seven percent. The disease is still spreading into currently unaffected cocoa-producing areas. There is a risk that the pathogen, Crinipellis perniciosa, may one day spread into the major cocoa-producing areas of West Africa and South East Asia, whose economies are at times almost completely dependent on exports of cocoa. This book describes the results of an authoritative, international study resulting from collaboration among plant pathologists in South America and the Caribbean with centres of expertise in the USA and UK. The experimental programme was directed towards the development of practical, reliable and economic methods of managing witches' broom disease in a number of cocoa-growing environments. To achieve this, a series of comparative experiments under different climate and disease pressure conditions was established in six countries. Experimental methods, the resultant comparative analyses and the conclusions drawn are described in the book. The project could serve as a future model for study of both temperate and tropical pathogens and the book should therefore be of interest to plant pathologists in general, as well as those with specific interests in cocoa pathology. In addition, it should appeal to students of epidemiology and technicians faced with similar pathology problems. This book should be of interest to students in epidemiology; plant pathologists in general, as well as those with specific interests in cocoa pathology.

Table of Contents:
1 Introduction to the international witches’ broom project.- Witches broom disease of cocoa — an overview.- Cocoa production in South America.- The international witches’ broom project.- Operational structure of IWBP.- Facilities and personnel involved in IWBP.- Training element of IWBP.- The experimental programme.- 2 The pathosystem.- The pathosystem in outline.- Aspects of the pathosystem.- Managing the pathosystem.- 3 The IWBP studies.- Comparative epidemiology experiment.- Gradients from isolated sources.- Comparative phytosanitation experiments: gradients in plantations.- Interpretation of results.- 4 Comparative epidemiology studies: introduction.- Methods for comparative epidemiology experiment.- Site profiles.- 5 Comparative epidemiology experiment: Brazil.- Methods.- Results and discussion.- Comparative analysis and discussion.- Conclusions.- Management implications.- 6 Comparative epidemiology study: Colombia Caldas and Llanos Orientales.- Methods.- Results and discussion.- Conclusions.- Management implications.- 7 Comparative epidemiology study: Ecuador.- Materials and methods.- Results and discussion.- Conclusions and disease management implications.- 8 Comparative epidemiology study: Grenada.- Methods.- Results and discussion.- Conclusions.- Management implications.- 9 Comparative epidemiology study: Trinidad.- Methods.- Results and discussion.- Conclusions.- Management implications.- 10 Comparative epidemiology study: Venezuela.- Materials and methods.- Results and discussion.- Conclusions.- Management implications.- 11 Comparative epidemiology of the witches’ broom pathosystem.- Climate.- Basidiocarp production.- Phenology of susceptible host tissue.- Disease dynamics.- Infection efficiency.- General discussion and conclusions.- Diseasemanagement implications.- 12 Disease gradients of Crinipellis perniciosa on cocoa seedlings.- Materials and methods.- Results and discussion.- Implications for disease management.- 13 Comparative phytosanitation studies.- Protocol methods.- Site description and results.- Summary of results of sanitation.- Implications for disease management.- 14 Witches’ broom in Bahia, Brazil.- Witches’ broom outbreak in Bahia.- Cocoa phenology and climate at Itabuna, Bahia.- Prediction of witches’ broom epidemics.- 15 Disease management: recommendations.- New plantings.- Existing plantations.- Rehabilitation.- Conclusions.- 16 Future prospects for improvements in disease management.- Phytosanitation.- Biological control.- Fungicides.- Disease resistance and breeding.- Appendix I IWBP committees.- Appendix II IWBP workshops.- Appendix III Theses published by IWBP students.- Appendix IV IWBP experimental protocols.- References.

Review :
This useful book gives an authoritative account of past and present research - Experiental Agriculture