CIP is spearheading a global effort to improve and facilitate research on potato late blight disease, the single most costly biotic constraint to global food production. The economic and agricultural havoc brought about by late blight disease affects millions of poor people worldwide who depend on potatoes as a staple and/or cash crop.

This plant disease—which can wipe out a potato field within weeks when weather conditions are highly favorable to the pathogen—has become the most costly ever documented. With resource-poor farmers in the developing world now spending more than $750 million per year on fungicides to control late blight while still losing an additional $2.5 billion in yield, the financial toll from potato late blight is well over $3.25 billion a year.

Many of those with the greatest need for the food and income potatoes can provide are becoming increasingly reluctant to take the risks associated with planting this potentially valuable crop.

GOALS. The Global Initiative on Late Blight (GILB) was convened by CIP in 1996 to address the escalating late blight problem brought about by the appearance of new, more aggressive, fungicide-resistant strains of the pathogen, Phytophthora infestans. Experts from both developing and industrialized countries met in Lima, Peru, to develop a collaborative plan of attack on late blight. Their discussions led to a three-phase, 10-year program, targeting specific priorities for each phase. The coordination role for GILB was assigned to CIP, Lima, Peru. This program was later revised during the 1999 and 2002 GILB Conferences and the role of GILB redefined.

The overarching goal of GILB is to enhance our ability to reduce the threat that late blight poses to the potato crop, with emphasis on developing countries, and one of the major aims of GILB is to bridge the knowledge and information gap between rich and poor countries.

GILB includes researchers, technology developers, and extensionists working worldwide to solve the late blight problem. There are almost 400 members from 65 countries forming seven regional groups—Africa, Central America (including Mexico), East and Southeast Asia and Australia, Europe and East Europe, South and West Asia, South America, and North America (USA and Canada).

OUTPUTS. GILB has played a unique role in bringing together researchers and extensionists from both industrialized and developing countries. This has occurred most visibly at three GILB-organized international meetings: 11–13 July 2002 in Hamburg, Germany; 16–19 March 1999 in Quito, Ecuador; and 17–20 March 1996 in Lima, Peru. The next GILB global conference is planned for 2005. Funding will be sought to ensure, as always, broad participation from developing countries. GILB regional groups, established during GILB’99, also meet at local scientific conferences and workshops.

Late blight first appears as a few grayish specks on the plant's leaves, and then a cottony film appears. Under certain climatic conditions, the disease can easily lead to the destruction of a whole field of potatoes.

Some of GILB’s most important outputs have been in the area of communications. GILB produces an Annual Report and the GILB Newsletter, and has an active website. Country reports describing pathogen populations and the importance and distribution of the disease, as well as successful and unsuccessful control measures, are being compiled and posted. A catalog of late-blight-resistant varieties lists potato cultivars presently grown in 39 countries and where to obtain them, along with general resistance information. Such resources as breeding lines, resistant materials, plant differentials, molecular markers, and Phytophthora infestans isolate collections and elicitors offered to other researchers by GILB members are posted on the website. Relevant techniques are described or links are provided. A member search option provides contact information and specific interests of researchers worldwide. Some GILB regional and thematic groups have their own web pages. All GILB publications are available online, including proceedings from international meetings since 1996.

At the meeting in Hamburg, the GILB Steering Committee identified specific needs that GILB will address or continue to address in the future to give more orientation and focus to the initiative. These needs include information on resistant cultivars, seed production technology, pathogen biology and population structure, epidemiology and management, training opportunities, availability of expertise, and the global and regional importance of late blight. Regional development needs include communication and organization in regions, proposal development, and support for securing funding.

Predicted global late blight severity for potato production zones expressed as the number of sprays needed to control late blight. The predictions are based on Simcast, a late blight forecasting model, linked to global climate surfaces in a geographic information system.

For more information, please visit our website http://gilb.cip.cgiar.org/index.php and/or contact Greg Forbes, Global Iniative on Late Blight Coordinator, Apartado 1558, Lima 12, Peru, or at g.forbes@cgiar.org