We have been having a lot of late blight questions this year. One important question many people are asking is "Is it safe to eat a tomato infected with late blight?" Here is a very informative and important answer to the question:
Yes, the unaffected parts probably are safe to eat. The conclusion unaffected tissue is safe to consume if diseased sections are adequately removed is based on several points. This pathogen does not produce a toxin that can make people sick, as a few plant pathogens can do. Plant pathogens cannot infect people. No food safety issues have been found with other diseases that affect tomato fruit or potato tubers.
Late blight appears to be like other more common diseases, in that these do not appear to affect plant tissue beyond the area of infection. Many home gardeners often cut off diseased tissue rather than throw out the entire fruit or tuber having found the healthy appearing part of these to taste fine. To date, this practice has not been associated with any human health issues.
Diseases like late blight are not considered a health concern for commercial tomato processing. Fruits are sorted to remove affected ones, but this is because of the impact on fruit quality. For home canning, only disease-free, preferably vine-ripened, firm tomatoes are recommended in the USDA Complete Guide to Home Canning because fungal pathogens may raise tissue pH (which has been supported by recent studies) and thereby allow growth of potentially harmful microorganisms, such as Salmonella. Deterioration can occur quickly after infection; therefore, affected tomatoes and potatoes should be salvaged and consumed right away.
This was taken from Cornell University's Department of Horticulture Web site, www.hort.cornell.edu. The most important message about consuming late blight is in bold. We are trying to get the word out that home gardeners should not can tomatoes infected with late blight.
Anne Lenox Barlow is the horticulture educator with Cornell Cooperative Extension in Clinton County. CCE offices may be reached in Clinton County at 561-7450; Essex County, 962-4810; and Franklin County, 483-7403. E-mail your questions to askMG@cornell.edu.