Independent Expert

Andrew Kniss

Associate Professor of Weed Ecology & Management, Department of Plant Sciences at the University of Wyoming

Andrew Kniss is an Associate Professor of Weed Ecology & Management in the Department of Plant Sciences at the University of Wyoming. He has a PhD in Agronomy with a minor in Statistics. Andrew's research program focuses on developing weed management programs in agronomic crops, especially sugarbeet, winter wheat, corn, and dry edible beans.

He has authored or co-authored 20 peer-reviewed journal articles and 1 book chapter. He teaches undergraduate and graduate level courses including Ecology of Plant Protection, Weed Science & Technology, and Applied Dose Response Analysis. He recently received the Outstanding Weed Scientist – Early Career award from the Western Society of Weed Science, and serves on the Board of Directors of the Weed Science Society of America. He grew up on a small farm in Nebraska. His interest in weeds began early in life after being forced against his will to pull nightshade berries out of dry bean windrows prior to harvest (he now thanks his dad for that experience).

From this Expert

Posted On: Monday, 9/23/2013 4:31 pm
A: The soil half-life of glyphosate is approximately 47 days (with a range of 2 to nearly 200 days depending on soil type and various environmental conditions). But it is not active for a vast majority of that time. In order for glyphosate to be active as a herbicide, it must first (obviously) enter the plant. But glyphosate binds very tightly to soil particles almost immediately upon reaching the soil, and pesticides are not absorbed by plants while they are bound to the soil. Glyphosate is... Continue Reading
Posted On: Tuesday, 7/30/2013 10:01 pm
A: Planting of Bt crops has significantly lowered the use of insecticides in cotton and corn. After over a decade of widespread Bt crop use, it is not too surprising that some insect pest populations are now evolving resistance to this trait. Consequently, farmers may be using insecticides to combat these Bt-resistant pests. It is important to note, though, that Bt-resistant insects are not the only reason for using an insecticide in addition to Bt corn hybrids; some farmers use the two tools in... Continue Reading
Posted On: Tuesday, 7/30/2013 8:13 pm
A: There is simply no reason to believe that there is any link between increased use of glyphosate and increased prevalence of Autism Spectrum Disorder (ASD). Certainly, glyphosate use has increased due to widespread use of glyphosate-resistant crops. And there also appears to be an increase in the prevalence in ASD over the same time period. But just because two things happen at the same time, does not mean there is a causal relationship (or any relationship, for that matter). For example,... Continue Reading
Posted On: Monday, 7/29/2013 3:06 pm
A: To really address this question, it is important to put “toxic poison” into perspective. It is true that pesticides are, by definition, toxic. But toxicity is relative; recall the old adage that the dose makes the poison. What may be a “toxic poison” to one species may actually be quite safe, and even a food source, to another. For example, chocolate is a toxic poison to dogs, but a nice treat to us. Pesticides should be considered in a similar context. Even though a pesticide is a toxic... Continue Reading

Are herbicides responsible for the decline in Monarch butterflies?

By Andrew Kniss (Independent Expert) on Thursday, May 15, 2014 - 18:01

Andrew Kniss discusses the decline in monarch butterfly populations and the claim that glyphosate-resistant GM crops are reducing milkweed habitat.
  • Impact on Environment