Tomato blight a growing problem in northeast

By Julia Green
JR Lawrence’s vegetable garden in the back yard of his Swart Street, Margaretville home is a source of a variety of summer vegetables. Cucumbers, broccoli, cabbage, carrots, parsnips, beans, carrots, beets, peppers and squash all line the perimeter of his yard, interspersed with floral plants like dahlias and black-eyed Susans.
There is one crop that will be noticeably missing from his late-summer produce, however: tomatoes.
About a month ago, Lawrence’s six tomato plants fell victim to late blight, a disease of which plant pathologists have reported an outburst in the region this summer.
“I don’t know if mine had it originally,” he said. “But Quarltere’s grows their own, so if somebody else in the village bought them from Wal-Mart or somewhere… in the Village of Margaretville, just one person needs to get it and it would spread to everybody.”
Late blight, the disease responsible for the devastating potato famine in Ireland in the 1840s, is one of the most ruinous diseases affecting potatoes and tomatoes around the world. If uncontrolled, it can result in complete destruction of potato and or tomato crops.
Generally, the blight makes its way to the northeast gradually from the south and reaches the local region in the fall, when people have already harvested their tomatoes. This year, however, experts familiar with the blight speculate that big-box stores imported their tomatoes from the south and the blight arrived in the northeast in late spring, after which it was airborne and spread to the gardens of local growers.
And garden hobbyists aren’t the only ones missing out: a number of farms in the Hudson Valley that have had to decimate their entire crops of tomatoes due to the disease.
Late blight makes its initial appearance on potato or tomato leaves as pale green, water-soaked spots that often originate at the tips or edges of the leaves. The marks quickly grow and change color to a dark brown or purplish black.
Other signs of blight are dependent upon the weather. In times of high humidity or wet conditions, a white moldy growth is often visible on the lower leaf surfaces. In drier conditions, infected leaves will dry up quickly and the white mold will disappear.
Late blight can also appear on green tomato fruit as large brown leathery lesions, which, in moist conditions, will develop into white mold growth and may ultimately result in a slimy rotting of the entire fruit.
Local growers of tomatoes should be especially vigilant about keeping an eye on their tomato plants, as, according to the Ohio State University Extension Fact Sheet on Plant Pathology for the Late Blight of Potato and Tomato, development of the blight “is favored by cool, moist weather [and] nights in the 50s and days in the 70s accompanied by rain, fog or heavy dew are ideal.”
The blight spreads easily and quickly, as spores are easily dislodged by wind and rain and can be blown into neighboring fields or gardens within a five- to ten-mile radius. Lesions may appear on plant leaves within three to five days of infection.
While farmers know the signs and how to dispose of infected plants, home gardeners are at risk of spreading the disease by incorrect disposal of affected plants.
At the monthly meeting of the Town of Middletown Town Board, Supervisor Len Utter announced that the Middletown Transfer Station will accept tomato plans for disposal to help stay the spread of the blight. While the transfer station does not generally accept lawn waste, tomato plants will be accepted in an attempt to help control the blight.
Local gardeners in the Town of Middletown who are concerned that their plants may have been exposed to the late blight are encouraged to dispose of their tomato plants.
To dispose of the plants, local gardeners should ensure that the tomato plants are in clear plastic garbage bags that are tied closed prior to transporting them to the transfer station, where the plants will ultimately be composted at the county landfill in Walton – a process that destroys the spores.