Jan 13, 2020 1:44 AM

Barton Ag Instructor Dr. Vic Martin - Was Resistance Inevitable? Part I

Posted Jan 13, 2020 1:44 AM
Barton Community College Ag Instructor Dr. Vic Martin
Barton Community College Ag Instructor Dr. Vic Martin

The Drought Monitor shows thing essentially unchanged from the previous week. Barton and Pawnee Counties remain in good shape with most of Stafford County listed as abnormally dry. Today’s topic may seem a bit early, or too late, and involves pesticide resistance developing in weeds and insects, especially weeds. Even most people not involved in agriculture are aware of resistance issues that have developed over the last four or so decades with the advent and increased usage of pesticides. Why be concerned now? Several reasons including all the challenges with new chemistries and the restrictions being placed on them for one. And a larger reason is how to we prevent this in the future? First, let’s look at how it happened.

The best place to start is to define a pesticide, something that kills a pest whether a disease, insect, or weed. For simplicity, let’s consider herbicides. Modern herbicides came into their own after WWII. All have one thing in common, they have a particular mode of action – how they kill the plant. Some are quite selective and only kill specific species or types of plants while others are nonselective and simply kill plants. There are many modes of action. Some target photosynthesis, some cellular respiration, while others affect cell division. And they target a particular aspect of a given biological process. They are grouped into different classes based on how they act.

Now let’s look at a selective herbicide, one that only targets certain species or types of plants – say a broadleaf herbicide such as dicamba. When sprayed on a field of corn it damages and hopefully kills broadleaf weeds like pigweed species. It is also sprayed on the corn but doesn’t harm the corn even though the corn takes it in. The corn is able to metabolize, or breakdown, the chemical so it doesn’t damage the crop.

Roundup ® or glyphosate was originally a nonselective herbicide and was effective on most, not all, plants. It didn’t matter if it was a broadleaf or grass. Even before the problems of today, glyphosate wasn’t equally effective on all plants. Some were harmed but not killed while others were resistant or able to metabolize the chemistry. By the mid-1990s Monsanto had developed and released Roundup Ready soybean and then corn cultivars which now include crops like alfalfa and canola. They were able to genetically engineer these crops to metabolize glyphosate.

Now what does this have to do with weed resistance? Say an average pigweed plant flowers. It is possible to produce well over one hundred thousand seeds and these are produced sexually so all the seeds are not identical genetically. So if you spray them with an herbicide they are susceptible to most will be affected and die. But out of say 100,000 seeds some will be different enough genetically they will not be killed or only damaged and able to produce seed and pass on that trait. A very few over time are going to be different enough that they are able to metabolize the chemistry and will essentially be resistant and they reproduce. So if a producer uses the same chemistry all the time without variation, the result is a shift in the plant population form susceptible to non-susceptible plants. The plants have evolved. This is what has happened.

Next week – Part II

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Jan 13, 2020 1:44 AM
Why Kansas CO2 emissions are at lowest level in 40 years
A wind turbine rises over Kansas. Brian Grimmett / Kansas News Service

By BRIAN GRIMMETT, Kansas News Service

WICHITA, Kansas — As global carbon dioxide emissions break records, Kansas is headed in the opposite direction — reducing emissions for 10 straight years.

Kansas’ decline is largely due to the rapid adoption of wind energy and a slow move away from coal powered electricity. That is to say: Kansas produces less carbon dioxide, or CO2, the powerful greenhouse gas that’s released into the atmosphere when we burn fossil fuels and is a major driver of climate change.

According to the U.S. Energy Information Agency, Kansas emitted 58.2 million metric tons of CO2 in 2017. That’s good enough to make Kansas only the 31st largest emitter in the U.S.

While it’s below the national average, on a global scale: “Kansas, if it were its own country, would be one of the top 60 CO2 emitters,” said Joe Daniel, an energy analyst at the Union of Concerned Scientists.

So, when Kansas sees a reduction in emissions like it has in the past decade, it matters, he said.

The decline began in 2007, when total CO2 emissions in Kansas peaked at nearly 80 million metric tons.

Where CO2 comes from

So how did the state reduce its annual CO2 emissions by as much as the entire country of Bolivia so quickly? Three graphics explain it all.

First, it’s helpful to know the source of Kansas’ CO2 emissions. In 2017, about half of total CO2 emissions came from burning fossil fuels, such as coal and natural gas, to create electricity. The rest was mostly from burning gasoline and diesel in our cars and trucks.

The recent reductions aren’t transportation-related, because, despite more efficient and cleaner burning engines, additional people and cars have offset the difference. In fact, total transportation emissions in Kansas have barely changed in the past 40 years.

That leaves electric power generation.

The decline of coal

As the graph shows, energy-related CO2 emissions began to plummet in the mid-2000s. Specifically, it’s emissions from coal-fired power plants.

While some of the reductions are likely due to plant upgrades and federal environmental regulations that forced coal plants to clean up what was coming out of their smoke stacks, it’s mostly because plants burned less coal.

Coal plants in Kansas only produced about 20,000 gigawatt hours of electricity in 2018, compared to an average of about 35,000 gigawatt hours during the 2000s.

Daniel said the decline is largely due to economics. With the fast growth of cheap wind-generated electricity in Kansas, it’s become less profitable to run coal plants.

“I don’t think a month has gone by where I haven’t read a study about the poor economics of either coal plants, or coal mines, or the companies that invest in those properties,” Daniel said.

The rise of wind

About 36% of all electricity produced in Kansas is from wind, the highest percentage of any U.S. state.

Twenty years ago, there was no such thing.

Part of the rapid growth of the industry is obvious: You wouldn’t put a wind turbine in a place with no wind, and there’s a lot of wind in Kansas.

Plus, federal and state tax incentives encouraged developers to jump into the market.

And it’s increasingly cheaper to build a wind farm.

Just this year, Kansas saw four new wind farms come online, adding enough capacity to power 190,000 homes for a year.

“Will we see four wind projects come online every year for the next five years? No,” said Kimberly Gencur-Svaty, director of public policy at the Kansas Power Alliance. “But I do think we’ll probably continue at a pace of where we’ve averaged the last 20 years, which is a project or two.”

How low can it go?

Ashok Gupta with the Natural Resources Defence Council said the move to renewable energy and subsequent decrease in CO2 emissions will be vital to reducing the impacts of climate change.

But, he wondered if it will be fast enough, especially in states that have a lot of wind.”

“We should be going by 2030 to pretty much carbon-free electricity,” he said.

While some states like Colorado have begun to adopt 100% renewable energy goals, Kansas has not. Even if Kansas were to get to 100% renewable energy, there’s still the nearly 20 million metric tons of transportation emissions to worry about.

Achieving a clean electrical grid will also be key to reducing those emissions, Gupta said, even if it also means another, different shift in the way things are currently done.

“We have to start making sure that our transportation and our buildings are moving to all electric,” he said. “That’s the strategy for the next 10 years.”

Editor's note: This story was corrected  on Dec. 30 to show the coal plants produced gigawatt hours of electricity, not megawatt, and that there are 20 million metric tons of transportation emissions, not 20 metric tons.

Brian Grimmett reports on the environment, energy and natural resources for KMUW in Wichita and the Kansas News Service. You can follow him on Twitter @briangrimmett or email him at [email protected] The Kansas News Service is a collaboration of KCUR, Kansas Public Radio, KMUW and High Plains Public Radio focused on health, the social determinants of health and their connection to public policy.