August 2, 2009

Godzilla vs. Phytophthora infestans - or The year of Zero Tomatoes

You may be noticing that tomatoes are doing poorly this year. We may have to worry about the H1N1 Swine Flu, but Tomatoes are worries about the early emergence and outbreak of the Potato Famine Blight, or 'Late Blight'.
No, not the summer;s biggest hit directed by Michale Bay, this is a real life horror, at least for Tomatoes. It's the fungus known as Phytophthora infestans, and this year, it is everywhere ensuring that practically no one will be harvesting tomatoes this year.

Some quick facts, first, no tomato variety is immune to this so forget thinking about next years crop being a variety of immune plants. Second, this is not a new disease, it's been around in the US since the 1840's, but if you are thinking in your head that you never remembered an outbreak like this when your parents gardened, you might be right, since many new strains have emerged since the 1990's that are more virulent. Third, the species Phytopthora infestans comes from Mexico, originally living in populations of other solanum species, but these newer outbreaks are a result of modern agricultural methods, over population and the migration of invasive species as we ourselves become more transient. Look, we may all want to blame someone like Wal Mart, Home Depot or any big box store, but the fact is that there are just too many of us humans moving virus' and fungi around. Since according to the US Dept. of Agriculture's Invasive Species page, this disease is caused by poor weather, excessive moisture for more than 8 hours, infected plants and wind. So although we may want to point fingers at the wholesale nursery, perhaps we should point the fingers at modernity and ourselves, for ultimately, the cause is overpopulation which has lead to global warming, climate change, the need for big box stores, etc etc etc. Still, I will grow tomatoes again, next year. Reality is that there isn't much I can do about this since I am equally at blame. IF we all sprayed fungicide, then we would not have this problem, right? But then we would piss off the organic gardeners, but then again, are they to blame? See? The blame game doesn't work. We just all need to be more aware and careful next year.

A recent article in the New York Times confirmed the rumor that a blight is ruining crops of tomatoes in the North East US from Maine to Georgia. The blight, called Late Blight, it the same blight that caused the Potato Famine in Ireland in the nineteenth century.
According to Newsday "Late blight disease is a fungus that causes white-mold encircled gray spots on leaves and stems that causes the plant to blacken, wilt and die. It's the same disease that caused the Irish Potato Famine in the 1840s, and it has never occurred this early or widespread in the United States.

Two weeks ago I had noticed that our plants we're becoming damaged, and although I attributed it to the unusually wet and cold summer we are having in the north east US, the damage, which consists of leaves shriveling and dieing from the ground, up, looked exactly like the fungus I usually get at the end of the summer. I expect this every year, since the soil I plant in had grown tomatoes for nearly 100 years, being that I live in my grandparents home. Even with raised bed, red plastic mulch and hay, I still get most every virus and fungus known, it seems. Tomatoes for me, always do best in containers, where I can use sterilized soil so that any soil based pathogen will not splash onto the foliage, but this year is extraordinarily bad. I think we will have no tomatoes at all, and I think I will be pulling the plants from the garden, and tossing the containers, since this latest outbreak of Late Blight is spread by spores in the air, all hope is lost for any big tomato harvest.

But something else stood out from the article, worth examining, and that is who is to blame. Interestingly, some experts are pointing fingers to the bog box stores, for spreading the blight. They even point out the exact grower, Bonnie Plants, a wholesale grower in Alabama. I don't have enough information beyond the NYT article, but apparently scientists have traced the genetic source to this grower. I am sure we will all know more, soon, but the concept is plausible. The grower denies the accusation, stating that the soil based pathogen exists everywhere, and has for a long time. Then of course, there is the weather, which has been record-breakingly cold and wet, so truly, who is to blame here.

According to the 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. Dennis Thomas, Bonnie Plants’ general manager, said five of the recalled plants showed signs of late blight.

Thomas, also noted earlier this month in Albany's Times Union newspaper, “We are not responsible" for late blight in the Northeast. As the nation's largest tomato plant producer, Thomas says Bonnie's grows hundreds of millions of tomato plants in over 60 locations each year in 38 states.

“If late blight shows up, we're going to get some of it," he noted in a phone interview. “But we're constantly doing our best to prevent it. No matter what we do, we can't overcome the ideal weather conditions late blight thrives on. Our name has been destroyed, and un-rightfully so."

There are two strains of late blight — tomato and potato — but the illness can jump from one species to the other. It is highly contagious: A single open lesion on a plant can produce hundreds of thousands of infectious spores. If you are an organic grower, the summer of tomatoes is done, or it never started. If you don't freak out about Fungicides ( as I don't, since, hey, I use bleach to sterilize pots and the toilet), then spray cautiously.

"Hot, sunny weather, which can kill late blight, could dramatically slow or eliminate the fungus’s spread over the next week, experts said. “I see a day like today that’s overcast and windy, those spores are flying around everywhere, and rain tonight will bring it all down to the ground,” Meg McGrath, a vegetable pathologist on the faculty of the Cornell horticulture research center in Riverhead, said on Thursday. “The disease loves these conditions.”

McGrath warns that home growers are at risk more than the commercial grower because of the difference in fungicides available to them, and overall knowledge about the disease. She likens the difference in chemicals available to an over-the-counter medicine and a prescribed medicine, as commercial farmers have licenses allowing for more potent products. But application of “over the counter" sprays, vigilant observance, and proper disposal of infected plants should work for home gardens, she said. Clipping leaves and stems on the bottom of plants helps prevent obtaining late blight, as rain drops often bounce off the ground and wet the plant, making it more susceptible to attracting infected spores.

"Fungicides can protect unaffected plants from disease, but there is no cure for late blight. Organic farmers, who are not permitted to use powerful synthetic fungicides like chlorothalonil, have very few weapons against this aggressive pathogen. Some home growers and organic growers are trying as a last resort, copper sulfate spray, but most will find this spray ineffective in the long run."

So what about potatoes?

Sadly, they are in trouble too, at least for the home grower and the organic grower. All plants related to Tomatoes can be affected including eggplants.

In the end, no matter if the blame game can pin point who is at fault or not, we in the North East and parts of the south will be relying on canned tomatoes for another year.

Even the Dahlia, Canna and the Bananas are not doing well at all this year, with the cold weather and rain.


  1. Great indepth post. Thanks for covering the detail of blight in all its horror ! And sorry that yours have succumbed.
    I am growing tomatoes in pots in the UK and we too have had a wet, cool summer. I bought some bordeaux mixture to use (contains 30% tetracopper tricalcium sulphate) and am just working up to spraying. I don't really want to but I know I will really regret that decision if I get blight.

  2. Great article! I live in the mountains of NC (zone 6). Several years ago we would lose all our tomatoes to this late blight just as the fruit would start to ripen. I even skipped growing them one year. But ever since we got two dairy cows and, thus, plenty of manure we haven't had a problem with the blight. My Brandy wines are 5 feet tall and loaded with green tomatoes. They are ripening a bit late due to the cool weather this summer but I think side dressing with plenty of manure has been the key for us to avoid the blight.

  3. Anonymous2:50 PM

    You need to read "Diet for a small Planet" It is NOT to many people....that is propaganda.....It is Gov. control...wake up!

  4. I have read 'Diet for a Small Planet', but propaganda? I find that hard to believe, but I do agree with you that Govt, too is to blame, but what do you suggest is the solution? Oregonian conspiracy theorists aside, the fact is that It is peopl, humans, who believe and spread propaganda, not plants and animals. If blame is to be had, it is us.

  5. Anonymous11:53 AM

    everyone needs to view "the world according to Monsanto"
    it's free on youtube.
    monsanto and syngento have been developing fungi for decades.
    they can spray fungi on crops.
    Clinton did it to the Columbian coca fields
    monsanto makes fungiside.
    2+2 equals crop failures.Google agro-terrorism, agro-business,
    just a little researce will revealshocking info.
    god help us.

  6. Thanks for the great post, t goes to show that no matter how hard us humans try to outwit mother nature she has a way of biting back.

  7. That's article doesn't cover the actual reason to over come this problem


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  8. Great post! I bought my two Bonnie plants at Home Depot in April and we cerrtainly had the cool, perpetually rainy weather in the mid-Atlantic last week. I have spent hours today trimming away the affected leaves and stems and have a question regarding all of the beautiful, large green tomatoes that are seemingly unaffected.. If there are no spots or discoloration of any kind on the tomatoes can they be eaten (fried or pickled/canned) or do they need to be tossed? I must have fifty or so but I am hesitant to move forward without knowing. Thanks!

  9. I have always been a lover of tomatoes and my greatest weakness is Italian dishes especially pasta with lots and lots of tomato sauce. There are many things that you can enjoy from eating tomatoes or tomato-based meals and drinking tomato juices.
    how to grow tomatoes


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