Late blight, a virulent, highly contagious fungus, is quickly destroying most of the field-grown tomatoes in the Northeast. To add insult to injury, late blight came early, undermining normal prevention methods.
This is a strain of the fungus that caused the Irish potato famine in the mid-1800s (supposedly brought there in the holds of ships from America). In as little as a couple of days, it can wipe out a field with hundreds of plants.
It has been about 15 years since agriculture here has been hit this hard.
“By the time you see black spots on the leaves or tomatoes, it’s too late,� said Gordon Ridgway, of Ridgway Farm in Cornwall. At the small, organic farm on Town Street, the family watched in dismay as 700 plants were wiped out almost overnight.
At McEnroe Farm in Millerton, Ray McEnroe reported 6,000 plants were hit.
“You could watch it spread through the field,� he said. “The worst part is there is nothing you can do about it. You can’t save any of them.�
Like influenza, the spores are always present to some degree. Like choosing to get a flu shot, or not, farmers have tough choices to make about whether they should use chemicals to protect their plants. And in that same vein, late blight has the ability to mutate and become resistant to herbicides — although most fungicides theoretically remain effective.
But organic farmers can only hope their plants will not be hit. If they spray, they lose their organic designation. If they don’t, they can lose their entire crop. Others take preventive measures, spraying a fungicide in late August or September, when an outbreak might typically occur.
What prompts an outbreak are the right conditions: plants, the presence of the spores and — mainly — wet weather. The spores, airborne on wind or in rain, stick to wet leaves. The longer they stay, the greater the risk of infection.
Until the last couple of weeks, hardly a day went by without some rain, triggering a blight of disastrous proportions.
A good impulse, tragic results
It could not have come at a worse time. But it is hardly an unfortunate coincidence. The irony is, the bad economy and an increase in interest in home-grown foods may be at the root of the problem. This summer has seen a huge increase in backyard gardens, planted by people trying to combat the rising cost of fresh food.
And home gardeners are unlikely to recognize blight when it appears and to pull up plants before their spores can become airborne.
“All it takes is one,� said Jude Boucher, an educator with the University of Connecticut Cooperative Extension System. “Just one infected plant can start an outbreak, but it would likely be pretty isolated. This year, we started out way behind the eight ball with tens of thousands of homeowners buying infected plants from big box stores.�
The infected seedlings have been traced to Wal-Mart, Home Depot, Lowe’s and Kmart stores and were sold as early as April. All of the stores in the Northeast buy from one distributor, Bonnie Plants, a 91-year-old company based in Union Springs, Ala., with 62 greenhouse complexes in 38 states. Cornell University claims it tracked the spore-carrying plants to a Georgia greenhouse.
Although the company’s owner denies responsibility, in late June it recalled the suspect plants, at a reported loss of about $1 million.
“Not that blaming anyone is going to change anything at this point,� Boucher said. “But I hope the USDA, which doesn’t normally do on-farm inspections, will be all over that grower next year.�
Farmers will see red
For farmers, financial impacts are difficult to determine.
“It depends on what kind of crop we would have gotten,� Ridgway said. “But it’s safe to say, because there is also a big investment in growing tomatoes, that even small farmers will lose thousands.�
Freund’s Farm Market in East Canaan counts on its popular tomatoes to attract shoppers to the store. The plants grow up to 10-feet tall in a dedicated greenhouse — where they are protected from airborne spores.
“Almost all of our tomatoes are in the greenhouse,� Theresa Freund said, “so we’re good.�
She did acknowledge there is a risk that ventilation systems will pull blight spores in, but remains confident.
“We got leaf mold in June, which is pretty common. We stripped our plants to control it. Our tomato crop is a little smaller, but demand is down so we’re OK.�
Freund said they last lost a crop of tomatoes in 1992. That was a wet summer, like this one, and all of the tomatoes rotted in the field.
Spores are spreading fast
Boucher reported spotty impacts across Connecticut, but predicted by the end of the month “only a lucky few will not be hit.�
In Putnam, he saw a 2-acre potato field that late blight “ripped through� in two days. The largest loss here to date is a 45-acre field in New Haven County.
In New York state, every county reports significant problems with the disease.
Tough tomato love: bag or burn it
Combating the problem is going to take some knowledge — and a lot of tough love.
Immediate measures to help stop the spread include pulling up tomato plants or cutting them at the stem, bagging plants in plastic and throwing them away. For large fields, burning with a propane torch is the recommended method.
While the spores won’t survive over winter and contaminate soil — they will succumb to both UV light and frost — they do get into potato tubers, where they can find a comfy home until spring.
“Farmers have to resist letting their potato fields get too bad. Some will try to let them go as long as possible to get potatoes big enough to harvest. That’s OK if they are ruthless about culling out and destroying anything that looks suspicious,� Boucher said. “In the spring, they have to be equally diligent about managing wild potatoes. If the tubers are affected this year, the new plants next year will have blight.�
Gardeners must also be careful not to put potentially infested plants into composters. Temperatures can remain high enough inside, even in the dead of winter, to incubate spores.
Boucher repeats: “All it will take is one,� meaning that if just one farmer or gardener fails to do a thorough cleanup, a massive blight can easily be triggered again next year.
Infested tomato fields should be dealt with quickly.
“Hanging on is a big mistake,� Boucher said.
Otherwise, the best immediate way to curb the spread is a few days of hot, dry weather, like those the past week has brought. It remains to be seen if the recent heat has done the trick.
A lesson to be learned here, Boucher said, is that anyone seeking to support locally grown produce by planting their own gardens should start by buying locally produced seedlings.
Submitted
