Gotham Grazer Blog

Fighting Biology with Biology

Could fungi be the best way for farmers to ward off pests?

A kudzu bug killed by  Beauveria bassiana , seen growing out of the body.  Courtesy of Brian Lovett/University of Maryland Entomology

A kudzu bug killed by Beauveria bassiana, seen growing out of the body.
Courtesy of Brian Lovett/University of Maryland Entomology

Use of fungal pesticides is on the rise, and their popularity may continue to increase over the next few years.  

What are the pros?
Most obviously, fungal pesticides do not affect human, animal or environmental health in the way that synthetic pesticides do.  They can target specific pests, rather than eradicating all biodiversity in an area.  And since they are living organisms, they can evolve with the pest, preventing resistance. 

The cons?
As of right now, fungal pesticides are more expensive than synthetic pesticides, which is an automatic turnoff for farmers.  Their effectiveness can also be altered by environmental conditions, such as humidity and temperature, making them less dependable.

For more details on this topic, check out the original article on NPR.

The Dose Makes The Poison

An article in The Washington Post is convincing readers that pesticide residues pose no risk, but it's a bit more complicated than that.

The Environmental Working Group keeps a “Dirty Dozen” list, which identifies the top 12 fruits and vegetables with the highest amount of pesticide residues.  The goal of the list is to educate consumers about what they are putting into their bodies, and to encourage them to purchase organic versions of these crops.  However, according to this article in The Washington Post, the list actually discourages people from buying fruits and vegetables all together.

A study performed by The Illinois Institute of Technology, where 500 low-income Chicago residents were surveyed on their organic/non-organic buying habits, found that upon learning about the “Dirty Dozen” list, consumers were less likely to buy any fruits and vegetables at all, regardless of their status on the list. 

Toxicologist Carl K. Winter says that consumers should not be wary about eating non-organic foods.  According to Winter, the pesticide residues on these fruits and vegetables “pose no risk to consumers,” because “actual exposure levels are typically millions of times lower than those that are of health concern.”  (There are many scientists and professionals that would disagree with this, but for the purposes of this blog post, we will assume that Winter is correct.)

In a nutshell, this article is saying that since there are nearly-zero health effects from pesticide residues, it is not necessary to buy organic produce. That’s worthy information to share with the public, but it ignores an important entity that does face true risks from pesticide usage: the environment.

When conventional farms use pesticides, they are contributing to the pollution of our air and water systems, diminishing biodiversity, and destroying soil health.  On the other hand, organic farms do the opposite - they deter pests without using synthetic chemicals.  This, along with other organic farming practices, can help to cleanse the environment of pollutants, improve biodiversity, and increase soil organic matter.  Organic farms become living ecosystems, whereas conventional farms have one goal: produce, produce, and produce. 

Although this article makes some valid points, it does a disservice to its readers by painting the picture that we shouldn’t bother with buying organic food.  Yes, you can be healthy without eating organic - this is something that we stress to our Gotham Grazer students all the time.  But in order to eat healthy and protect the planet, buying organic food is going to be necessary. 

Shedding Light on Genetically Modified Crops

Are genetically modified crops fulfilling their ultimate goal - solving hunger?

According to The New York Times, the answer is no.  This article takes a closer look at the failures (and successes) of GMOs, and unpacks a lot of the misconceptions and controversies surrounding the industry.  

Photo by Jeremy M. Lange for The New York Times

Photo by Jeremy M. Lange for The New York Times

The article compares crop yields and pesticide usage in Europe, where genetically modified seeds are outlawed, to North America, where genetically modified seeds are part of conventional farming methods. The results show that the U.S. and Canada have not seen any dramatic improvement in crop yields, while herbicide use has increased drastically:

"Since genetically modified crops were introduced in the United States two decades ago for crops like corn, cotton and soybeans, the use of toxins that kill insects and fungi has fallen by a third, but the spraying of herbicides, which are used in much higher volumes, has risen by 21 percent."

Such an increase in herbicide use has had noted effects on the environment, from the development of herbicide-resistant weeds to the pollution of groundwater.  Additionally, more herbicides means more toxic residues on our foods.  While many people argue that genetically modified crops are dangerous to humans, there is no scientific evidence that proves this; it is the over-use of pesticides, however, that has been shown to negatively impact human health.

What can we do?

When it comes to increasing yields, genetically modified crops are not getting the job done. And in any case, kicking production into high-gear on tired and depleted soils isn't exactly the most sustainable way to feed the rising population.  To truly address the issue of hunger, we need to adapt our cities and towns to be self-sufficient in crop production.  Abandoned lots, empty buildings, manicured lawns, and secure rooftops - such spaces exist almost everywhere, and they are the perfect places for gardens and greenhouses.  It's time to make locally grown food the solution!