Late blight (LB) is widely recognized as the single worst disease of food crops. The fungus-like pathogen Phytophthora infestans can rapidly adapt through mutation or migration, making efforts to combat it like playing leapfrog.
LB results in an estimated $10 billion worth of losses each year in potato crops of the developing world alone. The impact on developing countries is especially harsh as they are home to the majority of potato farmers, many of whom depend on potato for economic survival and food security.
An insidious problem related to LB is the health risk to farmers and their families as a result of chronic exposure to the pesticides employed to control the disease. The most common products used – dithiocarbamates, such as mancozeb – break down into suspected carcinogens.
Rising pressure from climate change is adding greater urgency to the problem. “With warming trends, which accelerate the spread of the disease, we are seeing increased risk in areas as diverse as the Andean highlands, the lake region of Sub-Saharan Africa, parts of Central Asia, and southwest China and Nepal, not to mention Northern Europe and the United States,” notes Greg Forbes, CIP plant pathologist.
In November 2009, CIP coordinated a meeting in Bellagio, Italy, uniting scientists from 21 developed and developing countries to plan a global strategy for combating LB disease.
The result was Late Blight: Action Plan for an Effective Response to a Global Threat, a white paper directed at policymakers and donors. It recommends five actions for employing rapid solutions to the LB problem based on existing capacities and technologies.