Aloe vera is a plant that is widely used for its medicinal and cosmetic properties, but its peels or rinds are usually discarded as waste.
However, a recent study has found that aloe vera peels could be used as a natural pesticide, helping farmers protect staple food crops from harmful insects.
How aloe vera peels can deter and kill insects
MAHMUD HAMS/AFP via Getty Images
The study, conducted by researchers from the University of Texas Rio Grande Valley and presented at the American Chemical Society meeting in August, showed that aloe vera peels contain bioactive compounds that can act as a feeding deterrent and insecticide for agricultural pests.
The researchers collected waste plastic from a beach in Ireland, where they found expanded polystyrene (EPS), a type of foam-like polyester that is used for insulation and packaging.
They noticed that the EPS had colonies of bacteria growing on it, which suggested that the bacteria could be using the plastic as a source of carbon and energy.
The researchers hypothesized that aloe vera peels have specific defense chemicals that repel or kill insects.
To test this, they collected and dried out the peels and then extracted the compounds with different solvents.
They then tested the extracts on two common crop pests: the fall armyworm, which attacks maize, rice, and wheat; and the diamondback moth, which attacks cabbage, broccoli, and cauliflower.
The results showed that the extract made with dichloromethane (DCM), a solvent commonly used in organic chemistry, had the highest insecticidal activity against both pests.
The DCM extract reduced the feeding and survival of the insects by more than 80%.
The researchers also identified six compounds from the DCM extract that were responsible for the insecticidal effect.
These compounds belong to different chemical classes, such as anthraquinones, chromones, and flavonoids.
The researchers explained that these compounds may interfere with the insects' nervous system, digestive system, or reproductive system, causing them to avoid eating, become sick, or die.
They also suggested that these compounds may have synergistic effects, meaning that they work better together than individually.
First, using aloe vera peels as a pesticide could help reduce the use of synthetic pesticides, which can have negative impacts on human health, soil quality, water resources, and biodiversity.
Second, using aloe vera peels as a pesticide could help reduce plastic waste, which is a major environmental problem.
Third, using aloe vera peels as a pesticide could help increase crop yields and food security, especially in developing countries where pests cause significant losses.
However, there are also some challenges and limitations that need to be addressed before using aloe vera peels as a pesticide on a large scale.
For one, the optimal dose and application method of the extracts need to be determined to ensure their effectiveness and safety.
There is also the issue on availability and cost of aloe vera peels need to be assessed to ensure their feasibility and affordability.
Moreover, the environmental fate and impact of the extracts need to be evaluated to ensure their biodegradability and non-toxicity.
Aloe vera peels could be a promising source of natural pesticides for food crops.
However, more research is needed to optimize and validate this method before it can be applied in practice.
