Tainan, Taiwan
December 11, 2009
Source: AVRDC The World Vegetable Center Newsletter
Over 160 years ago, late blight disease wiped out potato harvests in Europe, leading to massive starvation and the Irish potato famine. This year the disease decimated tomatoes and caused severe hardship to farmers in the northern United States. From 16-20 November 2009, late blight experts from 20 countries across the globe gathered in Bellagio, Italy to harness scientific resources and develop a robust and comprehensive strategy for defense against the disease. Dr. Mathew Abang, a plant pathologist at AVRDC – The World Vegetable Center, Regional Center for Africa, Tanzania, was part of the discussion.
You met with other scientists to map out a new battle plan to beat this old scourge. What makes late blight so devastating?
Late blight remains the single greatest threat to tomatoes and potatoes, two of the world’s most important crops in terms of income generation, food security, and nutrition. It is caused by a highly contagious, fungus-like pathogen— Phytophthora infestans—and it leads to billions of dollars of losses each year. Recent estimates are as high as $10 billion on potato alone.
While we do not have official global estimates for tomatoes, the disease equally accounts for several billion dollars in lost tomato production.
Late blight has been causing trouble for farmers for more than a century. Why the big fuss now?
Rising rates of hunger and malnutrition worldwide combined with the increased pressure of climate change add greater urgency to the problem. With climate change, the impact of late blight is
expected to worsen because rising temperatures accelerate its development and spread.
Why is late blight a difficult disease to control?
“Contagious” is the key word here. This pathogen ignores international boundaries. Dr. Greg Forbes, a plant pathologist at the International Potato Center and organizer of the Bellagio meeting, explained how late blight risk is increasing in areas as diverse as the Andean highlands, the northern USA, the lake region of sub-Saharan Africa, northern Europe, parts of Central Asia, and southwest China and Nepal. It can survive in a broad of a range of climatic and geographic conditions, and only a global plan of action will address the problem. This new initiative on late blight is a united effort to curb the pathogen.
Could you explain how late blight has a ripple effect in developing countries?
The impact on women in developing countries is especially harsh, as tomato production and marketing is a major source of income and women depend on the crop to fight poverty and
malnutrition. With the loss of a tomato crop, small-scale farmers are deprived of much-needed cash income and a prime source of micronutrients for health. Farmers and their families further risk chronic exposure to the pesticides they employ to control late blight. The most common products used – the dithiocarbamates, such as mancozeb – break down into suspected carcinogens.
Late blight threatens tomato production throughout the highlands of sub-Saharan Africa, including Madagascar. What is AVRDC doing to combat the pathogen?
AVRDC has developed tomato lines showing good field resistance so far in Tanzania. Efforts are being made to test these lines in other African highland locations and to develop lines with durable resistance as part of an integrated disease management strategy. As part of the New Initiative on Late Blight, our researchers will collaborate with other scientists on breeding for
late blight resistance; on the development side, capacity building to improve late blight management will be the focus. In Bellagio, we worked to assess the problem from multiple
perspectives, to design a global strategy capable of addressing priority needs and opportunities. As budgets decline for agricultural research, though, we will need to be innovative and creative in our approach. The group is working on a white paper to inform and educate policy makers in agricultural research and development on pressing needs for late blight research.
The East African Fresh Produce Journal highlighted AVRDC’s new late blight-resistant tomato varieties ‘Meru’ and ‘Kiboko’ in a recent issue.
READ MORE:
New Initiative on Late Blight: http://sites.google.com/site/bellagiolbnov2009/home
Topics
Species
