When farmers spray their fields with pesticides or other treatments only about 2% of the spray sticks to the plants. Much of it just bounces off the plant, lands on the ground , and becomes part of the run off the flows to our rivers and streams…often causing serious pollution.
MIT to the rescue.
A team of researchers at MIT has found a way to combine two inexpensive additives to the spray that greatly reduces the amount of spray that bounces off. First off we have to understand that many plants have a tendency to be hydrophobic(water repelling). The new approach will have the spray divided into two portions. One portion is given an additive with a negative electric charge, the other given an additive with a positive charge. When two of the oppositely charged droplets meet on a leafs surface they form a water attracting defect. that sticks to the surface and increases the retention of further droplets.
This project was aimed at assisting communities in India, and throughout the developing world. Spraying of pesticides is typically done from a tank on a farmers back, and since reducing the amount of pesticide wasted..reduces the farmers overall costs…and reduces the overall soil and water pollution.
The lab tests show the new system could allow farmers could get a good effect , but only use 1/10th as much pesticide or other spray. The polymer additives are natural and biodegradable and so will not contribute to runoff pollution.
This new approach looks promising in the lab, and with a bit off tweaking will be ready to take to the field shortly.