Charged polymers: A sticky solution for our pesticide problem

Charged polymers: A sticky solution for our pesticide problem

By Navneeta Kaul

A team of MIT researchers have developed an innovative additive-based approach to make pesticides “stickier”, increasing efficiency and reducing the amount needed to keep crops pest-free. This groundbreaking innovation has the potential to revolutionize the agriculture industry.

The pesticide problem:

Traditional pesticides have contributed to substantial increases in agricultural yields over the past few decades. Pesticides are used to prevent or control pests including weeds, insects, and plant pathogens. However, only 2% of the sprayed pesticides stick to plant surfaces while the other 98% goes off to waste. Due to the hydrophobic nature of plant surfaces, sprayed pesticides bounce off quickly. Wind-drift can also carry the sprayed pesticides away from the plants. As a result, pesticide residues leak into the soil or water resources leading to pollution. Moreover, these pesticides are toxic to biological organisms. Due to the ineffective retention of these pesticides on plants, farmers resort to the rampant use of pesticides which is costly and extremely harmful to the environment. Today more than ever, there is a critical need to modify pesticide formulations to enhance the retention of pesticides on the plant surfaces.

Designing effective agricultural sprays:

In recent years, multiple approaches have been used to improve pesticide drop retention on plants. One common approach is to add surfactants to the pesticide solutions. Surfactants cause a reduction in the surface tension and promote spreading of droplets on the plant’s surface. However, this approach has not been very beneficial as the droplets are more prone to wind-drift and rapid evaporation. The winner of the 2018 Lemelson-MIT student prize, Maher Damak, and his team have come up with a novel additive-based approach to increase pesticide deposition on plants. The additive, composed of a negatively charged polymer (polyacrylic acid) and a positively charged polymer (poly-ethyleneimine) is mixed with the pesticide solution. These polymers serve as a nucleation site for other molecules causing liquid retention. What makes this invention even more interesting is that the polymers are natural, FDA approved, biodegradable, biocompatible, and safe for the environment. This innovation could cut the pesticide usage and fix problems associated with pesticides.

Half of this leaf was sprayed with water (left) and the other half with charged polymers (right). The contrast in coverage is clear. Image courtesy of Maher Damak.

In a candid interview with Prescouter, Maher revealed that his pesticide additive formulation has generated a lot of interest in farmers. It has also attracted a lot of commercial interest as the solution is

“easy to use and can lead to a tenfold increase in pesticide retention. The polymers can be mixed with any water-based solution so the farmers can reap economic benefits by its usage”.

Usually, farmers have to wait from several hours to days to re-enter the fields after pesticide spray to avoid toxicity. Additive-based pesticides will limit the toxic-effects and avoid the associated health hazards.

What’s next?

The team intends to form a startup soon to bring the invention to the commercial market. Currently, the team is doing trials with farmers in Florida and Italy with an objective of replicating the results from the laboratory in the field. The results are being used to form a database of all the plants that respond well to the solution. So far, preliminary results seem to be promising for the plants tested, Maher tells PreScouter. With support from TATA Trusts from India, the team intends to foray into the developing countries of the world with this exciting innovation to boost agricultural production.

Maher Damak in a field trial site in Florida

With additive-based pesticides, crop yields could potentially increase which could feed an ever-expanding population. Moreover, farmers could save up to 10 times on pesticides, something that could seriously disrupt a market that generated over $50 billion revenue worldwide in 2016.


If you have any questions or would like to know if we can help you with your innovation challenge, please contact our Chemicals & Materials lead, Ryan Moran at rmoran@prescouter.com.

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