Late Blight: A Lesson in Buying Local?

If you have kept up with news in the Northeast, or the vegetable blogosphere, you may have noticed the term "late blight" cropping up in articles with overtones of desperation. My first exposure was an article by the New York Times entitled “Outbreak of Fungus Threatens Tomato Crop,” accompanied by a picture of some seriously sickly tomatoes (picture from NYT shown at left). Being the professed tomato enthusiast that I am, this headline immediately caught my eye as I scanned the homepage a few weeks ago. And it has only continued to infiltrate the news.

The fungus, called late blight, acts according to its name—it typically strikes tomato plants late in the season (around August or September) when conditions are cooler. The spores of this pathogen, officially titled Phytophthora infestans, are found in the soil and are incredible contagious, meaning that small outbreaks, while not uncommon, can be devastating. But this year the Northeast region, New York in particular, is experiencing a particularly wet June, which has caused a widespread outbreak that is both unprecedented and economically devastating.

In an area that typically sold locally-grown tomatoes at or below $20 a box (wholesale), consumers may soon be paying up to $40 a box. Doubling the price could be extremely harmful to area growers, and the farmers markets that display their wares. And with cases being reported as far west as Ohio, it is important that even mid-west growers are wary of this disease and its implications as the spread continues.

And beyond the statement of caution, what else can be taken from this article? Another reason to buy locally grown vegetables. Following is a quote from the original NYT article:

“Professor Fry, who is genetically tracking the blight, said the outbreak spread in part from the hundreds of thousands of tomato plants bought by home gardeners at Wal-Mart, Lowe’s, Home Depot and Kmart stores starting in April. The wholesale gardening company Bonnie Plants, based in Alabama, had supplied most of the seedlings and recalled all remaining plants starting on June 26."

Now, it is important to remember that big-box stores like those listed above, and even Bonnie Plants, are not responsible for the outbreak. This fungus has been around for years and the weather conditions have abetted its spread tremendously. But, the very nature of these larger stores makes it easier for pathogens, such as late blight, to spread more easily. Because, to echo the statements of Mr. John Mishanec (a pest management specialist at Cornell also quoted in the article) these garden centers are not required to undergo inspection by the Department of Agriculture, and their employees are not often trained to spot harmful diseases.

Having worked in my family’s greenhouses for over six years I can fully appreciate this statement. Each spring, John Day, who works for the Ohio Department of Agriculture, stops in to check out our Garden Center. Because he comes in every year he knows his way around, and usually just gives one of us the heads-up before meandering about the facilities. This visit results in a quick report and oftentimes a few updates concerning common “ailments” for the region (some years we are on the lookout for spider-mite on roses, some years its blossom end-rot, and some years it is simply aphids). His inspection, along with my Uncle Gerry’s degree in Horticulture, makes it possible for us to spot diseases/pests early on and treat them accordingly. This essential responsibility, to us, is simply another "given" when buying from local growers.

Unfortunately, this is the guarantee you won’t always get at a big-box store.

Now, I have done some checking around to see if late blight is something we ought to be worrying about in our region. After speaking with Tony Nye, OSU Extension Educator in Agriculture, and John Day, our Department of Agriculture inspector, it doesn’t look like late blight is cause for concern in our region just yet. This was reiterated by area farmer Brad Bergefurd, who reported similar symptoms in a few plants, but nothing that has been confirmed. (All three mentioned Blossom-End Rot as the larger concern for our region, for more information check out my earlier blog entry HERE).

To be safe, however, be on the lookout for symptoms of late blight, which include brown spots on leaves, fungal growth on underside of leaf (sometimes white), black spots on stem, and firm brown spots on tomato fruit.

For another grower’s perspective, and a personal account from the Northeast, check out the article Tomato Disappointment: A Farmer’s Perspective on Late Blight in the Northeast.

For a profile of the pathogen itself, check out this Science Daily article HERE.