In the heart of Puebla, Mexico, lies a small potato-farming village. It's the place where I was raised. The vibrant green of ancient forests has been overshadowed by the relentless expansion of ubiquitous non-organic potato farms that surround our local river which supplies water to our village. Growing up in this agricultural community, I witnessed firsthand the devastating impact of glyphosates, the chemical herbicides used widely in these potato farms. The once pristine forests, home to trees that have stood tall for centuries, have been stripped away, leaving behind sick animals and polluted Puebla rivers. It is a crisis that demands urgent attention and an innovative solution.

*A Puebla, Mexico forest and river decimated by pesticide and fungicide use for non-organic potato farming.* Glyphosates travel from the soil to the adjacent river and negatively impact the health of local Puebla villagers.

Glyphosate is not primarily used as a fungicide. It is a broad-spectrum herbicide that is widely used to kill weeds and other unwanted plants. It works by inhibiting an enzyme involved in plant growth, which leads to the death of the treated plants. Glyphosate is the active ingredient in many herbicide formulations, with the most well-known brand being Roundup. While glyphosate is not primarily a fungicide, there have been instances where it has been used to control fungal diseases indirectly. For example, if glyphosate is used to eliminate weeds that serve as hosts for fungal pathogens, it can indirectly reduce the spread of those pathogens. However, this is not its primary or intended use.

Glyphosates are a class of herbicides that have been widely used in agriculture for decades. However, there is growing concern about the environmental and health impacts of glyphosates. Numerous countries across the world have banned their use including Germany, the nation where Bayer A.G. is headquartered. Bayer A.G. is a multinational pharmaceutical and life sciences company that acquired Monsanto, the company that originally developed and produced the herbicide Roundup. This acquisition took place in 2018. As a result, Bayer now owns the Roundup brand and is responsible for its production and distribution. Roundup contains the active ingredient glyphosate and has been the subject of controversy and legal cases due to concerns about its potential health risks and environmental effects. Exposure to glyphosate, the world's most widely used herbicide, increases the risk of a cancer called non-Hodgkin lymphoma by 41 percent, according to an analysis from researchers in the UW Department of Environmental & Occupational Health Sciences [8].

UV-C light is a type of ultraviolet radiation that has been shown to be effective at killing fungi with 99.998% efficacy. In recent years, there has been growing interest in the use of UV-C light as a non-chemical fungicide. A recent 2022 study published on Wiley by researchers at the University of Florida found that “UV treatments applied once or twice weekly were as effective as the best available fungicides”, study author Natalia Peres, PhD said at the time. “It’s not a one-time fluke.” [6]. Fortunately, as this University of Florida research outlines, there is hope on the horizon. The emergence of UV-C as a potential replacement for glyphosates has sparked excitement among experts in the field of agriculture and vertical farming. This non-chemical and non-toxic alternative holds the promise of revolutionizing the way we approach fungicide use in agriculture. By harnessing the power of ultraviolet radiation, we can combat fungal pathogens while minimizing harm to the environment and human health. The research conducted by the University of Florida underscores the potential of UV-C light as a non-chemical alternative for fungicide management. The findings offer hope for farmers seeking sustainable fungi and pest control methods that minimize the use of toxic pesticides. While further research is needed to optimize UV-C application techniques and assess its effectiveness in different cropping systems, the study paves the way for a promising future where UV-C light could replace chemical fungicides and contribute to a more environmentally friendly and sustainable agricultural system.

UV-C radiation, specifically in the range of 200-280 nm, has been extensively studied for its ability to inactivate various viruses and pathogens, including the SARS-CoV-2 virus responsible for the COVID-19 pandemic [1]. This same mechanism of action can be applied to fungal pathogens in agriculture. The direct absorption of UV-C photons by nucleic acids and capsid proteins disrupts their structure, rendering the pathogens inactive and unable to cause harm [1]. Furthermore, recent research has shown that far UV-C radiation, in the range of 200-230 nm, is equally effective in pathogen inactivation and offers the advantage of minimal harm to mammalian skin and eye tissues [2].

*UV is a spectrum of light that is split into four spectral areas. Vacuum UV, or UVV (100 to 200 nm), UV-C (200 to 280 nm), UV-B (280 to 315 nm), and UV-A (315 to 400 nm).*

The potential benefits of UV-C and far UV-C in agriculture and vertical farming are substantial. These technologies provide non-chemical alternatives that reduce reliance on harmful pesticides, such as glyphosates. By adopting UV-C and far UV-C, farmers can cultivate crops without jeopardizing the health of local wildlife and water sources, a critical concern for communities like mine.

Several countries have already recognized the dangers of glyphosates and taken steps to ban their use. Austria, Luxembourg, and Malta were among the first to implement bans, citing environmental and health concerns [5]. France followed suit, with their ban motivated by the desire to protect biodiversity and public health [5]. Similarly, countries like the Netherlands, Italy, Norway, Qatar, Saudi Arabia, Argentina, and Thailand have restricted the use of glyphosates, signaling a global shift away from these chemical herbicides [5].

The bans on glyphosates highlight the urgent need for alternative solutions in agriculture. UV-C and far UV-C offer a path forward, not only by mitigating environmental and health risks but also by improving the efficiency and effectiveness of pathogen control. Recent studies have demonstrated that far UV-C radiation is three-to ten-fold more effective than conventional UV-C in killing fungal pathogens, such as Botrytis cinerea and Penicillium expansum, without negatively impacting plant health [3]. This greater efficacy translates into increased field area coverage and improved disease protection for crops.

The use of UV-C light as a fungicide has several advantages over the use of glyphosates. First, UV-C light is non-toxic to humans and animals. Second, UV-C light does not leave any harmful residues on the plants. Third, UV-C light is effective against a wide range of fungi. As concerns about the environmental and health impacts of glyphosates continue to grow, UV-C light is a promising alternative for controlling fungal diseases in agriculture. UV-C light is non-toxic, leaves no harmful residues, and is effective against a wide range of fungi. These advantages make UV-C light a potential replacement for glyphosates as a non-chemical fungicide.

*An estimated 6.1 billion kilos of glyphosate has been sprayed across resistant crops globally from 2005 to 2014, and is used at both industrial and consumer levels* [7].

Adopting UV-C technology in agriculture comes with its challenges. The infrastructure required for widespread implementation and the need for further research and development are significant considerations. However, the potential rewards are immense, not only for potato farming communities in Puebla but for agricultural practices worldwide. By embracing these innovative solutions, we can protect our forests, preserve biodiversity, and safeguard the health of both farmers and consumers.

In conclusion, the transition from glyphosates to UV-C in agriculture and vertical farming represents a paradigm shift towards sustainable and environmentally friendly practices. Farmers will have to learn to deploy UV-C via portable UV-C wands, UV-C tunnels, or UV-C robotics technologies, and this transition will take years to materialize. Despite the need for more research, the use of UV-C light as a fungicide is a promising development in sustainable, chemical-free farming. UV-C light is a non-toxic, residue-free alternative to glyphosates that could help to reduce the environmental and health impacts of agricultural production. The devastation caused by chemical herbicides can be reversed, and the health of our ecosystems restored. Let us draw inspiration from the forests that once flourished in my village and strive for a future where our agricultural methods align harmoniously with nature. Together, we can cultivate a greener, and healthier world!

- Arely Guerrero Valderrabano L.C.N. & Steven Grabenheimer

References:

Nature.com - UV-C irradiation is highly effective in inactivating SARS-CoV-2 [1]

Tandfonline.com - Far UV-C radiation: An emerging tool for pandemic control [2]

Sciencedirect.com - Potential of far ultraviolet (UV) 222 nm light for management of fungal pathogens [3]

Linkedin.com - Arely Guerrero Valderrabano's Post [4]

Liebertpub.com - A Review of Recent Evidence for Utilizing Ultraviolet Irradiation [5]

Wiley - https://onlinelibrary.wiley.com/doi/10.1002/ps.7263 [6]

DailyMail - https://www.dailymail.co.uk/sciencetech/article-11141171/Worlds-popular-weed-killer-Roundup-causes-dramatic-convulsions-worms-study-warns.html [7]

UW Department of Environmental & Occupational Health Sciences (DEOHS) - https://deohs.washington.edu/edge/blog/can-roundup-cause-cancer#:~:text=Exposure%20to%20glyphosate%2C%20the%20world's,Occupational%20Health%20Sciences%20(DEOHS). [8]