Aloe vera plant peels, typically discarded as agricultural waste, have been discovered by scientists to have insect-repelling properties. Meaning that they can serve as a natural insecticide for crops. 

We know by now that the aloe plant has long been used for treating wounds, skin issues, and promoting digestive health over thousands of years. So, this newfound discovery could represent a significant breakthrough in controlling insects that consume crop plants. 

“It’s likely that millions of tons of aloe peels are disposed of globally every year. We wanted to find a way to add value and make them useful,” said Debasish Bandyopadhyay, who was the primary investigator on the project, in a press release from the American Chemical Society (ACS). 

The team of researchers from the University of Texas Rio Grande Valley will present the results of their study at ACS’ fall meeting. 

Bandyopadhyay’s interest in the potential insect-repelling qualities of aloe plant rinds came around when he visited a local aloe production center with a colleague. 

During their visit, they observed insects attacking the plants but avoiding the aloe vera leaves. After gaining approval from the company’s CEO, Bandyopadhyay brought some aloe rinds back to the laboratory for further investigation. 

Aloe insecticide 

Home gardeners have actually been using aloe vera gel combined with ingredients like garlic and onions as a natural insecticide. However, the use of aloe peels isn’t that common.  

At an industrial scale, these peels are typically treated as agricultural waste and processed into biomass, which can improve soil quality on aloe farms. 

But according to experts, this practice isn’t really eco-friendly, as decomposition of agricultural waste generates methane and other harmful greenhouse gases that contribute to climate change. 

 

 

“By creating an insecticide that avoids hazardous and poisonous synthetic chemicals, we can help the agricultural field. But if the peels show good anti-mosquito or anti-tick activity, we can also help the general public,” Bandyopadhyay said. 

The primary investigator has been exploring the possibility of repurposing aloe peels to create a natural pesticide. This innovation could offer valuable assistance to farmers in regions such as India, Africa, and parts of the Americas, which have tropical and subtropical climates. 

Moreover, the development of this pesticide might offer an alternative and environmentally friendly approach to disposing of aloe peels. Also, it could provide aloe producers with additional sources of income. 

“The goal is to recycle this waste in a meaningful way while making aloe production greener and more sustainable,” said Bandyopadhyay. 

Finding the insect-repellent qualities 

During Bandyopadhyay’s research on the insecticidal potential of aloe peels, Bandyopadhyay and the research team started to air-dry the peels at room temperature without any exposure to light to preserve the plant’s bioactivity. Then, they tried getting various extracts using dichloromethane (DCM), hexane, methanol, and water. 

Before, the research team has reported that the extracts contained a compound called octacosane, which had mosquito-killing properties. But in the current experiments, the team found that DCM was more effective as an insecticide than the previous extract; this drove them to analyze the compounds further. 

In their newer investigation, the team found more than 20 compounds within the aloe vera peels—many showed antifungal, antibacterial, or other health-related benefits as well as insecticidal properties. Another good thing was that the compounds were found to be non-toxic; so they will be no significant safety concerns with the peels. 

In the future, Bandyopadhyay and the team plan to do more tests to examine if the insecticidal qualities could get rid of pesky insects in agricultural settings. Additionally, they’re also exploring the potential anti-tick or anti-mosquito properties of these compounds so that us regular consumers can use it. 

“By creating an insecticide that avoids hazardous and poisonous synthetic chemicals, we can help the agricultural field. But if the peels show good anti-mosquito or anti-tick activity, we can also help the general public,” Bandyopadhyay said. 

 

 

Needing for more natural insecticide/pesticide 

As we move towards a greener future, we also need more developments that are least harmful towards the environment. According to a recent report by the Institute of Environmental Sciences (CML) from Leiden University, Dutch surface water contains too many toxic pesticides. In the Netherlands, there’s a similar crisis with nitrogen. 

“We will have to improve our ways of life together with many sectors in the Netherlands,” said Minister Harbers.  

The environmental organization Natuur & Milieu commissioned the CML to study 153 natural and recreational areas in the Netherlands. More specifically, it studied the presence of the 38 most toxic chemical pesticides in surface water. 

Between 2014 and 2021, the harmful substances were found in 80% of these areas. What’s concerning is that in 40% of these locations, the pesticide levels went beyond established environmental standards, sometimes surpassing them up to a hundred times. Simply out, there’s a significant threat to the aquatic life in these areas. 

Studying the substances 

The study focuses on substances categorized by the European Union as Candidates for Substitution (CfS). Basically, this classification indicates that some substances or products carry a certain level of risk, but they are essential in agriculture.  

As a result, they will only be replaced when some other practical alternatives become accessible. 

Ecologist Marco Visser, who led the study, said, “Substances on this list may be carcinogenic or disrupt reproduction.”  

It is also known that some of these substances can affect soil organisms. Now, soil may not seem so urgent, but organisms like fungi and worms are a crucial foundation for healthy ecosystems and food production. 

Visser stated, “Since 2014, there has been a general improvement in water quality when looking at the combined toxicity of all measured pesticides. However, there seems to be little improvement when specifically looking at CfS substances.”  

 

 

Minimal improvement 

In their report, Visser and colleagues note that their findings are consistent with earlier studies that also showed no significant decline in the rising of standards from 2014 to 2021. The continuous presence of these pesticides isn’t surprising, since their use hasn’t been reduced significantly. 

The constant use of the conventional pesticides goes against the Dutch government’s goal set in 2013, which aimed to reduce the exceeding amount of toxic substances in surface water by 90% by 2023.  

Moreover, by 2027, all European Union member states must meet the targets set out in the European Water Framework Directive. Back in May 2022, the Council for the Environment and Infrastructure (Rli), warned that the current policies were unlikely to meet these goals.  

If there’s no change, this could lead to consequences for economic activities beyond 2027, similar to the Dutch nitrogen crisis. 

To address this issue, Binnenlands Bestuur contacted Minister Mark Harbers, to which Harbers responded with a statement that the government is committed to doing whatever’s possible to meet the goals. However, the minister realized that not everything is as simple as they seem.

“Not only to prevent the Netherlands from coming to a standstill but also to ensure an adequate supply of fresh drinking water. So, there is no choice but to achieve this. We will have to improve our ways of life in many sectors in the Netherlands,” Harbers said.

The incongruence between water quality and pesticide policies 

The Netherlands is a place where many rivers meet; at the same time, it’s responsible for over 50% of the pollution, Harbers also have his comment about the relaxed approval process for certain pesticides as a concern since their regulations are more lenient compared to rules to maintain water quality. 

Going forward, Harbers planned to harmonize these two systems in collaboration with the European Commission. As for now, the ministry is in the process of developing an “impulse program” to speed up improvement in water quality. 

 

Sources

https://www.ecowatch.com/aloe-peels-insecticide.html  

https://phys.org/news/2023-09-news-reveals-pesticides-dutch-natural.html  

https://www.express.co.uk/life-style/garden/1776426/natural-pesticide-protect-plants-pests