It’s as if the Black Plague had come again to do its ghastly work.
“Why are they dying?” many are asking. “What’s killing them?”
They mean, thank goodness, what’s killing tomatoes – not people.
One neighbor down the street had a prolific tomato garden, starting to blush from pink to bright-red, when in just a few days the hundreds of plumplings turned scabby-brown and soggy, rapidly rotting. The same thing happened to another neighbor’s tomato patch. It made me glad I decided not to plant tomatoes this season. I didn’t have to because I have a pantry whose shelves are lined with canned pasta sauce, tomato chunks and salsa from last summer’s bountiful crop.
Because my last year’s crop was so prolific, people assumed I’d know the answer to why tomatoes are dying. I didn’t. But I was determined to find the answer. So I called one of my favorite trusty resources – the Stearns County University of Minnesota Extension Service.
The question no more than tripped from my lips, when Brenda said, “Late blight. Oh yes, it’s late blight.”
She told me the Extension Service has been peppered with questions about this season’s decimated tomato gardens. The decimation is statewide, Brenda noted.
Like a vicious invading army, late blight is caused by fungus-like organisms called oomycetes. Its scientific name is the lethal-sounding phytophthora infestans, and infest it certainly does, like gangbusters. It’s a scourge of both tomatoes and potatoes and can wipe out entire fields of those crops in a matter of days.
Brenda said this season’s weather was the “perfect storm” for the spread of late blight. Despite the heat spells, there were periods of cool and damp weather. Late blight is caused by spores that germinate like wildfire after they’ve infected a tomato (or potato) plant. Thriving on moisture, they cause lesions on the leaves and stems and on the tomatoes themselves – lesions that resemble dried splotches and dark-brown scabby patches. In just one day, under “ideal” damp conditions, a lesion can produce up to 300,000 spores. The spores quickly spread to other plants and also become windborne, traveling to other areas, other tomato patches. Thus the rampant tomato infection gallops on like one of the dreaded Four Horsemen, wielding his deadly scythe.
Tomato plants can be susceptible to “early blight” and to “septoria leaf spot,” although those infestations are unlikely to kill the entire plant. Late blight is merciless. At least it doesn’t over-winter, but all tomato plants should be destroyed and any “volunteer” plants that might pop up next spring from seeds from this year’s infected plants should be removed immediately come May.
Late blight is so lethal it caused the horrific Irish Potato Famine in the 1840s during which an estimated 1 million people died of starvation and another million emigrated, many of them to the United States. Ireland, like other northern European countries, had become dependent on potatoes as an easily grown food crop after it was brought to the New World from Peru. Unlike many crops, the potato is a complete food, meaning people can survive on it even when other food sources are lacking in the diet. Thus, in poverty-stricken Ireland, so many were utterly dependent on potatoes. When the late blight struck, misery followed. To this day, it’s heartbreaking to read about the suffering of that famine, with accounts of children eating seaweed and bark in a futile effort to survive while parents, too hungry even to cry, looked on helplessly.
Sadly, such famines, caused by many factors, still happen with terrible regularity, such as in the Sahel zone of northern Africa.
Most of us can thank our lucky stars we are not dependent on a one-crop diet. We are fortunate the United States and most other countries have a thriving and varied agricultural network. Yes, the loss of garden-patch tomatoes is disappointing. Yes, the scourge of phytophthora infestans was rampant this season. But in the larger scheme of things, so what?
Next spring, we will plant our tomatoes and, once again, we will hope for the best.
