Weeds that like a sip of Roundup now and then
First the glorious days of advanced farming brought us corn stalks that eat tractor tires. Now there’s a weed that likes to drink weed killers, especially Roundup. Recently Palmer amaranth “completely overran” most of the soybean test plots at Bayer CropScience’s test plots in Illinois, in the words of DTN/Progressive Farmer editor, Pam Smith, despite having an arsenal of herbicides thrown at it. She describes some of the plots as “forests of pigweed.” I shouldn’t joke about this because it really is a serious problem, but I just can’t help it. At least 20 years ago, in New Farm magazine, a Rodale publication I was working for at the time, we reported weeds becoming immune to herbicides and the herbicide industry hee-hawed us for being organic nitwits. So pardon me while I hee-haw right back.
Palmer amaranth is one of about 60 recognized kinds of pigweed or amaranth (we call it redroot in my neck of the woods). The Palmer type is native to the arid southwest but finds other climates just fine, especially in drought years. First it marched across the southern states and now is invading the Midwest. I have a great hunch that other pigweeds like the kind that plagues my garden will also become glyphosate-resistant if they haven’t already. Ironically, the weedkiller industry is now advocating crop rotation along with their herbicides as the way to control weeds, which of course is what wise farming understood long before Roundup came around.
What makes this situation almost amusing is that Palmer amaranth is at least 8000 years old and makes nutritious food for humans. Amaranth was a staple in the Aztec diet as well as Mississippian Indian cultures of the mound-building era. To this day, the seeds or grains of this “weed” are popped and mixed with honey to make a popular snack in Mexico called alegria. Grain amaranth is still found in seed catalogs (Seeds of Change, for one). Back in the 1970s and 80s, the Rodale Institute, under the aegis of Bob Rodale, began seriously to experiment with pigweed and the Rodale Institute remains today an excellent source of information on it. The first time I saw a whole field of pigweed in neat, long rows on the Rodale farm, I nearly went into cultural shock. This weed, which I had been taught from childhood was consummate evil, was arrayed in agronomic splendor across the landscape. But I became convinced that Bob was onto something and for quite a few years wrote enthusiastically about farmers and gardeners who tried to grow amaranth as a food crop.
But American society is not geared for pigweed farming. The seeds are so tiny that they are devilish hard to harvest and handle with piston engine power. Prehistoric hunters and gatherers painstaking gathered and ground the grain into good food because that’s what they did. We will still hunt and gather wild nuts, berries, mushrooms and fish for fun but not for work. We don’t do pigweed because we don’t need to do it and there’s no cultural glamor in it. We could change, I suppose. Harvesting marijuana is just as painstaking as harvesting pigweed but quite a few people are willing to do that, it seems. There may come a day when that will be true of pigweed too and it won’t be illegal. Until then, we must try to poison nutritious free food into extinction to suit the goals of industrial grain production. Some days I wonder if it might not be better to culturally engineer humans to enjoy small scale garden farming than to genetically engineer weeds to save large scale agribusiness.