By SHELLY STRAUTZ-SPRINGBORN
Michigan Correspondent

RIVERSIDE, Calif. — The University of California, Riverside, recently was awarded a $9 million five-year grant from the USDA National Institute of Food and Agriculture (NIFA) to research late blight in potatoes and tomatoes.
Howard Judelson, a professor of plant pathology at UCR, received the grant. He will lead a multidisciplinary team of extension faculty and researchers – plant pathologists, molecular biologists, epidemiologists, plant breeders, sociologists and economists – at universities, government labs and a nonprofit research institution nationwide.

Late blight, caused by a fungus-like microbe, is a plant disease that mainly attacks potatoes and tomatoes. It was largely responsible for the Irish Potato Famine in the mid-19th century.

With world potato production weighing in at about 320 million tons per year – 20 million tons in the United States – and the world tomato production totaling about 120 million tons per year, with 13 million tons in the U.S., late blight is a major problem worldwide. Total costs of the disease are estimated at more than $7 billion per year, which can drive farmers out of business and increase food prices.

Judelson said the research will emphasize providing growers with better tools for managing the disease. These include better systems for making disease management decisions, plant varieties that are more resistant, tools for rapid identification of the pathogen and tools for characterizing pathogen strains.
The researchers also will test and expand the use of social media and smart phone technology to communicate with growers.

“Late blight is a global problem,” Judelson said. “To manage this disease, which is favored by cool, moist weather, we need a multipronged approach. In this research project, we will develop an integrated plan of research, education and extension that includes developing diagnostic tools, resistant plants through breeding and biotechnology and systems to provide improved management guidelines to growers.

 “If we know what is found in a certain state at the beginning of an epidemic, and we know what the traits are, we can inform growers the disease is there and give them information about how to tailor disease management to that particular genotype in that area. In the first year, we will be able to tell them if the disease is present. In subsequent years, we will have more information about the strains.

“With this information, we will be able to help growers tailor their fungicide applications, depending on whether the strains are resistant to fungicides,” he added.

Judelson said researchers also hope to identify whether a particular genotype is more aggressive on tomatoes or potatoes in an effort “to make management of the disease more efficient.

“We’re hoping the tools we are developing will help the average grower reduce the number of spray applications per season,” he said.

USDA Under Secretary for Research, Education and Economics Cathie Woteki recently visited Riverside to make a formal announcement of the research grant and meet with Judelson as well as other UCR scientists and administrators.
“More than 40 percent of current crop production among the top 10 food crops is lost to pests and diseases annually and that is a huge loss for farmers,” Woteki said. “USDA is funding this project to help agricultural producers win the future, by ensuring our country can keep producing the food needed to meet rising global demand in a sustainable way.”

Late blight symptoms include the appearance of dark lesions on leaf tips and plant stems. In humid conditions, white mold appears under the leaves. Infected potatoes show gray or dark patches outside; inside, such potatoes show reddish brown lesions.

A threat to home gardeners and commercial farmers, the disease can wipe out tomato and potato fields within a week.

The disease is caused by Phytophthora infestans, the most significant pathogen of potatoes and a noteworthy tomato pest. Spores of the pathogen primarily travel in air, eventually landing on plants where they colonize leaves and cause them to die. Spores also can enter the soil to reach potato tubers and destroy them. Available fungicides tend to be expensive and have potentially adverse environmental effects. Moreover, some strains of the pathogen are resistant to some fungicides.

In the U.S., late blight is seen predominantly on potatoes in Eastern states such as Maine, New York and Pennsylvania, and outbreaks also occur in the Midwest and West. Tomato production from Florida up the East Coast is also vulnerable to the disease. In California, late blight is mostly seen in the central valley in the early season, when conditions are moist and cool.

UCR will be joined by scientists at Purdue University; the University of Kentucky; Cornell University; the USDA-Agricultural Research Service in Corvallis, Ore.; the University of Idaho; the Scottish Crop Research Institute; North Carolina State University; the University of Florida; La Universidad Autónoma Chapingo, Mexico; the Boyce Thompson Institute; the University of Maine; Oregon State University; Pennsylvania State University; the University of Wisconsin; the University of Maryland; and the University of South Carolina.
Of the $9 million total award, $4.3 million is budgeted to UCR for research and education activities; the rest will be shared among the other 16 institutions.