Andrew Kniss

Herbicide resistance predates herbicides by over 80 years

July 27, 2016February 15, 2018 - by Andrew Kniss

The Weed Science Society of America (WSSA) recently posted a press release headlined “WSSA Scientists Say Herbicide Resistance Predates Genetically Engineered Crops by 40 Years.” From the WSSA release: You may think weeds resistant to herbicides are a new phenomenon linked to the overuse of glyphosate in genetically engineered crops, but according to the Weed Science Society of America (WSSA) nothing could be further from the truth. This year marks only the 20thanniversary of glyphosate-resistant crops, while next year will mark the 60th anniversary …

Spraying a herbicide study (video)

June 24, 2016February 15, 2018 - by Andrew Kniss

I took this video a couple weeks ago with a GoPro attached to our small-plot research sprayer. I thought I’d post it here in case anyone was interested in how we apply herbicides for our research. We also use a lot of hand equipment, but this rig works great for our larger studies (4 acres in this particular trial). A commercial rig could cover 4 acres in just a few minutes, but it took us about 6 hours to do …

As consumers shift to non-GMO sugar, farmers may be forced to abandon environmental and social gains

May 12, 2016February 15, 2018 - by Andrew Kniss

Dan Charles at NPR has recently done two interesting pieces about sugar production. In the first, he uses sugar as a proxy to look at the environmental costs and trade-offs of growing food in different places. It makes for an interesting comparison because there are two completely different crops (sugarcane and sugarbeet) that can be grown to produce the exact same product, refined sugar. The two crops have very different climatic needs, pest management requirements, and growing seasons. It is an …

What does a GMO label tell you about herbicide use?

March 24, 2016February 15, 2018 - by Andrew Kniss

There has been quite a bit of discussion lately about various food companies deciding to label their products for GMO content in response to Vermont’s GMO labeling bill. I’m still mostly indifferent to GMO labels, and frankly, have grown tired of this particular debate. But there seems to be at least one misconception that I wanted to briefly address. If you follow the GMO issue at all, you’re probably aware that a large majority of GMO crops currently being grown are herbicide …

Agroecology / Crops / GMO / Herbicide Resistance / Herbicides / Imported from Control Freaks

Everything in Agriculture is a Trade-Off

March 14, 2016June 7, 2019 - by Andrew Kniss

The idea of trade-offs is familiar to everyone. None of us have unlimited money, time, or energy. We make decisions every single day about how to spend our money, our time, and our energy. Do I buy the red shirt or the blue shirt? Do I watch the football game or go to the concert? Should I ride my bike to work or hope I can find a good parking place? Do I call a plumber or try and fix the sink myself? Do …

Herbicide Diversity Trends in US Crops, 1990-2014

February 2, 2016February 15, 2018 - by Andrew Kniss

There are two things that I think just about every weed scientist can agree on: herbicide resistant weeds make weed management more difficult; and the key to battling herbicide resistant weeds (or any weeds, really) is to use a diverse weed management program. One aspect of a diverse weed management program is herbicide diversity. The quickest way to select for herbicide resistant weeds is to use the same herbicide over and over again. I’ve expressed heavy skepticism in the past …

How to Make a Natural Weed Killer

January 6, 2016February 15, 2018 - by Andrew Kniss

Well over a year ago, I wrote about a homemade herbicide containing salt, vinegar, and dish soap. “Many of you have probably seen it posted to Facebook or Twitter or Pinterest, or on your favorite home gardening site. One of my favorite descriptions calls it a “magical, natural, weed killing potion.” That particular potion certainly kills weeds, but it isn’t natural (and it certainly isn’t chemical-free). It contains dish soap and vinegar, both of which are synthesized industrially, so it isn’t natural by most definitions of the word. That’s disappointing, …

The role of reflected light quality in crop-weed interactions

December 15, 2015February 15, 2018 - by Andrew Kniss

This post is a slightly edited excerpt from an article we wrote for Reflections magazine. Plants need light – this is one of the first biology lessons children learn in school. Plants convert sunlight into forms of energy the plant can use to grow. Nearly everything humans eat is derived in some way from photosynthesis, whether the tomato picked from a garden or a ribeye steak that once grazed on grass. Sunlight seems like a plentiful enough resource, but there’s …

Enlist Duo registration being withdrawn by EPA due to “synergistic effects”

November 25, 2015February 15, 2018 - by Andrew Kniss

Chris Clayton at DTN is reporting this morning that EPA is withdrawing registration of Enlist Duo herbicide. The decision was posted yesterday in court documents. From the DTN report: “The filing was posted in a Ninth Circuit Court of Appeals case filed by the Natural Resources Defense Council and the Center for Food Safety against Dow AgroSciences and EPA over the regulatory approval of Enlist Duo.” Withdrawal of the herbicide’s registration will effectively make it illegal to use this herbicide, …

The cost of preventing herbicide resistance

November 16, 2015February 15, 2018 - by Andrew Kniss

In my last post, I reviewed some recent research that suggests one of the best ways to delay the evolution of herbicide resistant weeds is to use mixtures of effective herbicides. Resistance is initially a very rare trait within a weed species, so the probability that any particular individual plant will be resistant to two herbicides is extremely low. The second herbicide is likely to kill any weeds that are resistant to the first herbicide, and vice versa. The theory behind this practice …