Potato late blight

W. Pérez � G. Forbes


Potato late blight

© International Potato Center (CIP), 2010

ISBN 978-92-9060-391-7

CIP publications contribute important development information to the public arena.

Readers are encouraged to quote or reproduce material from them in their own

publications. As copyright holder CIP requests acknowledgement, and a copy of the

publication where the citation or material appears. Please send a copy to the

Communication and Public Awareness Department at the address below.

International Potato Center

P.O. Box 1558, Lima 12, Peru
cip@cgiar.org � www.cipotato.org

Cover picture: Ricardo Orrego

Produced by the CIP Communication and Public Awareness Department (CPAD)

Production Coordinator

Cecilia Lafosse

Design and Layout

Elena Taipe and contributors from Graphic Arts

Printed by Tarea Asociación Gráfica Educativa

Press run: 300

June 2010



Preface 5

Introduction 7

The pathogen 9

The disease 16

Management of late blight 19

Evaluation of late blight resistance 28

Literature 32




The development of new technologies has given specialists a better understanding of

the biology of

Phytophthora infestans (Mont.) de Bary. However, much of this information is

presented piecemeal in specific publications that at times are difficult to understand. Inte-

grating all the new information can be even more difficult. This guide is an attempt to

present some of the new information in a summarized form that gives a broad view of the

problem. The CIP (International Potato Center) Project for Integrated Management of Late

Blight has developed a wide variety of training activities for professionals, technicians and

community leaders, as well as participatory research programs using the Farmer Field School

methodology to facilitate knowledge transfer. Furthermore, integrated management strate-

gies have been developed together with national researchers and rural development institu-

tions, considering agro-ecosystem care, farmer and environmental health, all of which are

particularly affected by inappropriate and inefficient use of fungicides.

We hope this guide will be useful for researchers, teachers, students, technicians and

farmers interested in this topic. Chapters on the pathogen, the disease and integrated man-

agement attempt to cover as much information as possible. For this reason, special care has

been taken in analyzing some of the specialized and recent bibliography in order to present

the information in a didactic and objective way. The chapter on evaluation of disease resis-

tance has been laid out based on specialists’ experience and aims to be a useful guide for

those who need to evaluate resistance of new varieties or evaluate new control strategies.

The authors

“He who loves practice without theory is like the sailor who boards ship without a rudder and

compass and never knows where he may cast. “

Leonardo da Vinci